WO2018116991A1 - Method for decomposing polyoxalate - Google Patents
Method for decomposing polyoxalate Download PDFInfo
- Publication number
- WO2018116991A1 WO2018116991A1 PCT/JP2017/045158 JP2017045158W WO2018116991A1 WO 2018116991 A1 WO2018116991 A1 WO 2018116991A1 JP 2017045158 W JP2017045158 W JP 2017045158W WO 2018116991 A1 WO2018116991 A1 WO 2018116991A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- polyoxalate
- chelating agent
- oxalic acid
- water
- crack
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 32
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 claims abstract description 169
- 239000002738 chelating agent Substances 0.000 claims abstract description 57
- 235000006408 oxalic acid Nutrition 0.000 claims abstract description 53
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 44
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 36
- 229910001424 calcium ion Inorganic materials 0.000 claims abstract description 28
- 230000007062 hydrolysis Effects 0.000 claims abstract description 26
- 238000006460 hydrolysis reaction Methods 0.000 claims abstract description 26
- 239000002516 radical scavenger Substances 0.000 claims description 32
- 150000001875 compounds Chemical class 0.000 claims description 16
- 238000000354 decomposition reaction Methods 0.000 claims description 13
- VXYADVIJALMOEQ-UHFFFAOYSA-K tris(lactato)aluminium Chemical compound CC(O)C(=O)O[Al](OC(=O)C(C)O)OC(=O)C(C)O VXYADVIJALMOEQ-UHFFFAOYSA-K 0.000 claims description 7
- ABLZXFCXXLZCGV-UHFFFAOYSA-N Phosphorous acid Chemical compound OP(O)=O ABLZXFCXXLZCGV-UHFFFAOYSA-N 0.000 claims description 5
- KXDHJXZQYSOELW-UHFFFAOYSA-N Carbamic acid Chemical compound NC(O)=O KXDHJXZQYSOELW-UHFFFAOYSA-N 0.000 claims description 4
- CKLJMWTZIZZHCS-REOHCLBHSA-N L-aspartic acid Chemical compound OC(=O)[C@@H](N)CC(O)=O CKLJMWTZIZZHCS-REOHCLBHSA-N 0.000 claims description 4
- 235000003704 aspartic acid Nutrition 0.000 claims description 4
- OQFSQFPPLPISGP-UHFFFAOYSA-N beta-carboxyaspartic acid Natural products OC(=O)C(N)C(C(O)=O)C(O)=O OQFSQFPPLPISGP-UHFFFAOYSA-N 0.000 claims description 4
- 230000001737 promoting effect Effects 0.000 abstract description 4
- 229940116315 oxalic acid Drugs 0.000 description 45
- QXDMQSPYEZFLGF-UHFFFAOYSA-L calcium oxalate Chemical compound [Ca+2].[O-]C(=O)C([O-])=O QXDMQSPYEZFLGF-UHFFFAOYSA-L 0.000 description 30
- 239000012530 fluid Substances 0.000 description 28
- 239000000243 solution Substances 0.000 description 25
- 239000011575 calcium Substances 0.000 description 16
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 15
- 239000007789 gas Substances 0.000 description 15
- 239000007788 liquid Substances 0.000 description 15
- 238000005185 salting out Methods 0.000 description 15
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 13
- 150000003839 salts Chemical class 0.000 description 11
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 10
- 239000002245 particle Substances 0.000 description 10
- 238000001556 precipitation Methods 0.000 description 10
- 239000007864 aqueous solution Substances 0.000 description 9
- 239000013078 crystal Substances 0.000 description 8
- 229920000747 poly(lactic acid) Polymers 0.000 description 8
- 239000004626 polylactic acid Substances 0.000 description 8
- 239000000843 powder Substances 0.000 description 8
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 7
- 239000001110 calcium chloride Substances 0.000 description 7
- 229910001628 calcium chloride Inorganic materials 0.000 description 7
- 239000000463 material Substances 0.000 description 7
- 238000006116 polymerization reaction Methods 0.000 description 7
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- -1 aluminum lactate Chemical class 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- QKNYBSVHEMOAJP-UHFFFAOYSA-N 2-amino-2-(hydroxymethyl)propane-1,3-diol;hydron;chloride Chemical compound Cl.OCC(N)(CO)CO QKNYBSVHEMOAJP-UHFFFAOYSA-N 0.000 description 4
- FYBLWUVZITWWEZ-UHFFFAOYSA-N Cl.[Ca] Chemical compound Cl.[Ca] FYBLWUVZITWWEZ-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 239000000872 buffer Substances 0.000 description 4
- 238000004821 distillation Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000002844 melting Methods 0.000 description 4
- 230000008018 melting Effects 0.000 description 4
- 239000002244 precipitate Substances 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- JNELGWHKGNBSMD-UHFFFAOYSA-N xanthone Chemical compound C1=CC=C2C(=O)C3=CC=CC=C3OC2=C1 JNELGWHKGNBSMD-UHFFFAOYSA-N 0.000 description 4
- DCCWEYXHEXDZQW-BYPYZUCNSA-N (2s)-2-[bis(carboxymethyl)amino]butanedioic acid Chemical compound OC(=O)C[C@@H](C(O)=O)N(CC(O)=O)CC(O)=O DCCWEYXHEXDZQW-BYPYZUCNSA-N 0.000 description 3
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- LOMVENUNSWAXEN-UHFFFAOYSA-N Methyl oxalate Chemical compound COC(=O)C(=O)OC LOMVENUNSWAXEN-UHFFFAOYSA-N 0.000 description 3
- 229960005261 aspartic acid Drugs 0.000 description 3
- 239000013522 chelant Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- 150000002009 diols Chemical class 0.000 description 3
- 230000003301 hydrolyzing effect Effects 0.000 description 3
- 239000003112 inhibitor Substances 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 238000005065 mining Methods 0.000 description 3
- 239000003345 natural gas Substances 0.000 description 3
- 239000003002 pH adjusting agent Substances 0.000 description 3
- 238000002360 preparation method Methods 0.000 description 3
- 230000002829 reductive effect Effects 0.000 description 3
- URDCARMUOSMFFI-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(2-hydroxyethyl)amino]acetic acid Chemical compound OCCN(CC(O)=O)CCN(CC(O)=O)CC(O)=O URDCARMUOSMFFI-UHFFFAOYSA-N 0.000 description 2
- SZHQPBJEOCHCKM-UHFFFAOYSA-N 2-phosphonobutane-1,2,4-tricarboxylic acid Chemical compound OC(=O)CCC(P(O)(O)=O)(C(O)=O)CC(O)=O SZHQPBJEOCHCKM-UHFFFAOYSA-N 0.000 description 2
- HEDRZPFGACZZDS-UHFFFAOYSA-N Chloroform Chemical compound ClC(Cl)Cl HEDRZPFGACZZDS-UHFFFAOYSA-N 0.000 description 2
- 229940120146 EDTMP Drugs 0.000 description 2
- 102000004190 Enzymes Human genes 0.000 description 2
- 108090000790 Enzymes Proteins 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- DBVJJBKOTRCVKF-UHFFFAOYSA-N Etidronic acid Chemical compound OP(=O)(O)C(O)(C)P(O)(O)=O DBVJJBKOTRCVKF-UHFFFAOYSA-N 0.000 description 2
- 229920002907 Guar gum Polymers 0.000 description 2
- QPCDCPDFJACHGM-UHFFFAOYSA-N N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC(O)=O QPCDCPDFJACHGM-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- YDONNITUKPKTIG-UHFFFAOYSA-N [Nitrilotris(methylene)]trisphosphonic acid Chemical compound OP(O)(=O)CN(CP(O)(O)=O)CP(O)(O)=O YDONNITUKPKTIG-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 125000002947 alkylene group Chemical group 0.000 description 2
- 238000005422 blasting Methods 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 2
- NFDRPXJGHKJRLJ-UHFFFAOYSA-N edtmp Chemical compound OP(O)(=O)CN(CP(O)(O)=O)CCN(CP(O)(O)=O)CP(O)(O)=O NFDRPXJGHKJRLJ-UHFFFAOYSA-N 0.000 description 2
- 150000002148 esters Chemical group 0.000 description 2
- 229960004585 etidronic acid Drugs 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000002657 fibrous material Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 239000008187 granular material Substances 0.000 description 2
- 239000000665 guar gum Substances 0.000 description 2
- 229960002154 guar gum Drugs 0.000 description 2
- 235000010417 guar gum Nutrition 0.000 description 2
- 239000012263 liquid product Substances 0.000 description 2
- 229910052749 magnesium Inorganic materials 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 150000007522 mineralic acids Chemical class 0.000 description 2
- 150000007524 organic acids Chemical class 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 229960003330 pentetic acid Drugs 0.000 description 2
- 235000011007 phosphoric acid Nutrition 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000002455 scale inhibitor Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000006228 supernatant Substances 0.000 description 2
- 230000001629 suppression Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 239000002562 thickening agent Substances 0.000 description 2
- DIWZKTYQKVKILN-VKHMYHEASA-N (2s)-2-(dicarboxymethylamino)pentanedioic acid Chemical compound OC(=O)CC[C@@H](C(O)=O)NC(C(O)=O)C(O)=O DIWZKTYQKVKILN-VKHMYHEASA-N 0.000 description 1
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- BYEAHWXPCBROCE-UHFFFAOYSA-N 1,1,1,3,3,3-hexafluoropropan-2-ol Chemical compound FC(F)(F)C(O)C(F)(F)F BYEAHWXPCBROCE-UHFFFAOYSA-N 0.000 description 1
- 125000001140 1,4-phenylene group Chemical group [H]C1=C([H])C([*:2])=C([H])C([H])=C1[*:1] 0.000 description 1
- ZXNFXBYPFOIXKT-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(carboxymethyl)amino]-4,4-dihydroxybutanoic acid Chemical compound OC(O)CC(C(O)=O)N(CC(O)=O)CCN(CC(O)=O)CC(O)=O ZXNFXBYPFOIXKT-UHFFFAOYSA-N 0.000 description 1
- RAEOEMDZDMCHJA-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-[2-[2-[bis(carboxymethyl)amino]ethyl-(carboxymethyl)amino]ethyl]amino]acetic acid Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CCN(CC(O)=O)CC(O)=O)CC(O)=O RAEOEMDZDMCHJA-UHFFFAOYSA-N 0.000 description 1
- DMQQXDPCRUGSQB-UHFFFAOYSA-N 2-[3-[bis(carboxymethyl)amino]propyl-(carboxymethyl)amino]acetic acid Chemical compound OC(=O)CN(CC(O)=O)CCCN(CC(O)=O)CC(O)=O DMQQXDPCRUGSQB-UHFFFAOYSA-N 0.000 description 1
- IKEUZCGOPYSHNN-UHFFFAOYSA-N 2-[bis(carboxymethyl)amino]benzoic acid Chemical compound OC(=O)CN(CC(O)=O)C1=CC=CC=C1C(O)=O IKEUZCGOPYSHNN-UHFFFAOYSA-N 0.000 description 1
- CIEZZGWIJBXOTE-UHFFFAOYSA-N 2-[bis(carboxymethyl)amino]propanoic acid Chemical compound OC(=O)C(C)N(CC(O)=O)CC(O)=O CIEZZGWIJBXOTE-UHFFFAOYSA-N 0.000 description 1
- BHPQYMZQTOCNFJ-UHFFFAOYSA-N Calcium cation Chemical compound [Ca+2] BHPQYMZQTOCNFJ-UHFFFAOYSA-N 0.000 description 1
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 1
- FCKYPQBAHLOOJQ-UHFFFAOYSA-N Cyclohexane-1,2-diaminetetraacetic acid Chemical compound OC(=O)CN(CC(O)=O)C1CCCCC1N(CC(O)=O)CC(O)=O FCKYPQBAHLOOJQ-UHFFFAOYSA-N 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 206010053759 Growth retardation Diseases 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 235000011941 Tilia x europaea Nutrition 0.000 description 1
- 235000008853 Zanthoxylum piperitum Nutrition 0.000 description 1
- 244000131415 Zanthoxylum piperitum Species 0.000 description 1
- 239000008351 acetate buffer Substances 0.000 description 1
- RUSUZAGBORAKPY-UHFFFAOYSA-N acetic acid;n'-[2-(2-aminoethylamino)ethyl]ethane-1,2-diamine Chemical compound CC(O)=O.CC(O)=O.CC(O)=O.CC(O)=O.CC(O)=O.CC(O)=O.NCCNCCNCCN RUSUZAGBORAKPY-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical group 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- DIZPMCHEQGEION-UHFFFAOYSA-H aluminium sulfate (anhydrous) Chemical compound [Al+3].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O DIZPMCHEQGEION-UHFFFAOYSA-H 0.000 description 1
- 125000002029 aromatic hydrocarbon group Chemical group 0.000 description 1
- 238000009412 basement excavation Methods 0.000 description 1
- CDQSJQSWAWPGKG-UHFFFAOYSA-N butane-1,1-diol Chemical compound CCCC(O)O CDQSJQSWAWPGKG-UHFFFAOYSA-N 0.000 description 1
- MWQHNOBPQBRERZ-UHFFFAOYSA-N butane-1,4-diol;dibutyl(oxo)tin Chemical compound OCCCCO.CCCC[Sn](=O)CCCC MWQHNOBPQBRERZ-UHFFFAOYSA-N 0.000 description 1
- KQBTUOVABZLXGP-UHFFFAOYSA-N butane-1,4-diol;ethane-1,2-diol Chemical compound OCCO.OCCCCO KQBTUOVABZLXGP-UHFFFAOYSA-N 0.000 description 1
- 230000009920 chelation Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 150000001805 chlorine compounds Chemical class 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 125000000113 cyclohexyl group Chemical group [H]C1([H])C([H])([H])C([H])([H])C([H])(*)C([H])([H])C1([H])[H] 0.000 description 1
- JGFBRKRYDCGYKD-UHFFFAOYSA-N dibutyl(oxo)tin Chemical compound CCCC[Sn](=O)CCCC JGFBRKRYDCGYKD-UHFFFAOYSA-N 0.000 description 1
- 238000000113 differential scanning calorimetry Methods 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 230000009422 growth inhibiting effect Effects 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 238000005342 ion exchange Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 239000004571 lime Substances 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 1
- 125000001624 naphthyl group Chemical group 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 235000005985 organic acids Nutrition 0.000 description 1
- 238000001139 pH measurement Methods 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 1
- 229920001748 polybutylene Polymers 0.000 description 1
- 239000004926 polymethyl methacrylate Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- UYCAUPASBSROMS-AWQJXPNKSA-M sodium;2,2,2-trifluoroacetate Chemical compound [Na+].[O-][13C](=O)[13C](F)(F)F UYCAUPASBSROMS-AWQJXPNKSA-M 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 125000000383 tetramethylene group Chemical group [H]C([H])([*:1])C([H])([H])C([H])([H])C([H])([H])[*:2] 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
- 235000020681 well water Nutrition 0.000 description 1
- 239000002349 well water Substances 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/06—Clay-free compositions
- C09K8/12—Clay-free compositions containing synthetic organic macromolecular compounds or their precursors
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C59/00—Compounds having carboxyl groups bound to acyclic carbon atoms and containing any of the groups OH, O—metal, —CHO, keto, ether, groups, groups, or groups
- C07C59/01—Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups
- C07C59/08—Lactic acid
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F5/00—Compounds containing elements of Groups 3 or 13 of the Periodic System
- C07F5/06—Aluminium compounds
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/25—Methods for stimulating production
- E21B43/26—Methods for stimulating production by forming crevices or fractures
Definitions
- the present invention relates to a polyoxalate decomposition method that hydrolyzes polyoxalate in water, and more specifically, underground resources such as petroleum, natural gas, and shale gas are collected using a hydraulic fracturing method.
- the present invention relates to a method of hydrolyzing a polyoxalate used as a flow path controlling agent.
- the technique using the hydraulic fracturing method is widely adopted to collect underground resources.
- this method for example, as disclosed in Patent Document 1, first, a well formed by excavation with a drill or the like is filled with a fluid. The fluid is then pressurized to generate a crack from the well. Through this crack, underground resources such as oil and gas are collected.
- Such a method is also called a hydraulic fracturing method, and the fluid used in this method is also called a fracturing fluid.
- the generation of cracks significantly increases the cross section of the well's resource inflow, and the underground resource can be efficiently collected.
- it is widely applied to mining of shale gas produced from a relatively shallow underground layer.
- a preliminary blast called perporation is performed in a horizontal well prior to the generation of cracks due to fluid pressurization.
- Such preliminary blasting produces a large number of small cracks along with relatively large cracks in the deep part of the well.
- the fluid flows into these cracks by press-fitting the fracture fluid into the well.
- a load is applied to these cracks, and the cracks grow to a size suitable for resource collection.
- a hydrolyzable material that temporarily closes the crack may be used.
- a diverting agent that temporarily closes a part of a crack that has already been generated may be used.
- This flow path control agent is sometimes called a sealing material. That is, a part of the crack that has already been formed is closed with a flow path control agent, and the fluid filled in the well is pressurized in this state, so that the fluid enters the other crack. Thereby, the crack grows greatly, and many large cracks can be generated effectively.
- a hydrolyzable material is used as such a flow path control agent. This is because it is necessary to temporarily close the crack and to have a property of decomposing with time.
- Patent Documents 1 and 2 disclose using polylactic acid powder or polylactic acid fibrous materials as the flow path control agent. Since such a flow path control agent hydrolyzes and disappears with time, environmental pollution due to remaining in the ground can be effectively prevented. Moreover, it does not hinder the collection of gas and oil as resources.
- polyoxalate (or polyoxalate copolymer) is more hydrolyzable than polylactic acid and has a faster hydrolysis rate at low temperatures. Furthermore, it has the characteristic as a hydrolysis promoter which accelerates
- polyoxalate is surely superior in hydrolyzability than polylactic acid, and also has a function of promoting hydrolysis of polylactic acid, and is expected to be put into practical use as a flow path control agent.
- the hydrolyzable advantage may not be fully exhibited. That is, the flow path control agent penetrates into the crack already generated in the well by pressurization using the fracturing fluid and closes the crack. Can be effective. Further, in the pressurization for the next generation of cracks, it is possible to prevent the cracks already generated from collapsing. Further, after generating an effective number of cracks for gas recovery, the flow path control agent hydrolyzes to open the closed cracks. When polyoxalate is used as a flow path control agent, the cracks are not sufficiently opened, often resulting in inconvenience that the cracks are closed by solid particles, impeding its practical use. is there.
- an object of the present invention is to provide a polyoxalate decomposition method in which polyoxalate is hydrolyzed without producing solid particles that close cracks.
- Another object of the present invention is to provide a flow path control agent that is suitably used when generating cracks for natural resource mining by hydraulic fracturing using a fracturing fluid.
- the present inventors have conducted many experiments on the hydrolysis of polyoxalate in water, and as a result, when Ca is present in water, the calcium oxalate produced by the hydrolysis of polyoxalate cracks. The present inventors have found that this is a cause of clogging particles and have completed the present invention.
- a polychelate that promotes hydrolysis of polyoxalate by coexisting a chelating agent for capturing Ca ions or an oxalic acid scavenger reactive with oxalic acid or oxalate in the water is provided.
- the chelating agent is represented by the following formula: X ⁇ Y Where X is the molar amount of the chelating agent, Y is the molar amount of Ca ions present in the water, Used in an amount that satisfies the conditions expressed by (2)
- the chelating agent is any one of an aminocarboxylic acid chelating agent, a phosphonic acid chelating agent, and an aspartic acid chelating agent, (3)
- the oxalic acid scavenger is either Al or an Al compound, (5)
- the Al compound is aluminum lactate, Is preferred.
- the present invention further provides a flow path control agent comprising a polyoxalate and an oxalic acid scavenger.
- a flow path control agent comprising a polyoxalate and an oxalic acid scavenger.
- an Al compound particularly aluminum lactate, is preferably used as the oxalic acid scavenger.
- polyoxalate decomposition method of the present invention a means of allowing a chelating agent to coexist in water in which the polyoxalate is hydrolyzed is employed. That is, polyoxalate produces oxalic acid and alcohol by hydrolysis, but oxalic acid produced by hydrolysis reacts with Ca (particularly Ca ions) present in water to produce calcium oxalate. This calcium oxalate precipitates as crystal particles, and these particles are a factor and remain in cracks formed by hydraulic crushing. As a result, it becomes difficult to collect underground resources (for example, shale gas and natural gas) from the crack.
- underground resources for example, shale gas and natural gas
- the polyoxalate decomposition method of the present invention aims to improve the efficiency of collecting underground resources using the hydraulic crushing method by suppressing the precipitation of calcium oxalate as described above.
- the object of the present invention can be achieved by capturing oxalic acid or oxalate. That is, in the polyoxalate decomposition method of the present invention, a means is adopted in which an oxalic acid scavenger reactive with oxalic acid or oxalate coexists in water in which the polyoxalate is hydrolyzed.
- generated by the hydrolysis of polyoxalate reacts with an oxalic-acid capture
- the production of calcium oxalate is suppressed, and it is possible to effectively prevent clogging of cracks formed by hydraulic crushing.
- generation by hydraulic fracturing The graph which shows the precipitation amount of the calcium oxalate in Al and Ca ion coexistence.
- ⁇ Principle of crack generation> When mining resources using a fluid (fracturing fluid), as shown in FIG. 1, a preliminary blast (perpendicular) is carried out in the deep portion of the well 1 that is drilled by a drill or the like and extends in the horizontal direction. Thus, a large crack 3a and a small crack 3b are formed (see FIG. 1A).
- the large cracks 3a can be used for collecting resources as they are, but the number thereof is small and it is not sufficient for efficiently collecting a large amount of resources. For this reason, the operation
- a diverting agent 5 is used as the flow path control agent 5.
- a hydrolyzable resin powder or a fibrous material is used as the flow path control agent 5.
- Such a flow path control agent 5 is normally added to the fluid press-fitted into the well. When this fluid is press-fitted into the well, the flow path control agent 5 enters the large crack 3a, thereby closing the large crack 3a (see FIG. 1B).
- the fluid pressure effectively acts on the portion other than the crack 3a. For example, a large fluid pressure is applied to the small crack 3b generated at the time of the first preliminary blasting, and the crack 3b grows greatly, so that the whole well 1 has a suitable size for collecting resources. Thus, the crack 3a can be formed.
- the flow path control agent 5 needs to be decomposed to open the closed crack 3a. This is because shale gas and natural gas are collected through the crack 3a as described above. For this reason, as the flow path control agent 5, hydrolyzed resin powder or the like is used.
- polyoxalate is excellent in hydrolyzability at low temperature.
- it is excellent in hydrolyzability at a temperature of 50 ° C. or lower, and therefore has been proposed for use as the flow path control agent 5.
- a gas existing in a relatively shallow formation such as shale gas
- it exhibits moderate hydrolyzability particularly at a temperature of 50 ° C. or less, and as soon as possible after forming the crack 3a by hydraulic fracturing. This is because the polyoxalate satisfies such required characteristics.
- the precipitation of calcium oxalate can also be effectively prevented by allowing an oxalic acid scavenger that captures oxalic acid or oxalate to coexist in water in which polyoxalate is hydrolyzed. Therefore, by using the oxalic acid scavenger instead of the chelating agent or together with the chelating agent, the hydrolysis performance of the polyoxalate can be effectively exhibited.
- the polyoxalate used as the hydrolyzable resin material is a polymer having an ester unit composed of oxalic acid and a diol as a main constituent unit.
- This main structural unit is represented by the following formula (1): —COCO—O—R 1 —O— (1)
- R 1 is a diol residue. It is represented by The diol residue R 1 is typically an alkylene group such as methylene, ethylene, propylene, butylene, etc., and most preferably ethylene or butylene.
- This polyoxalate can be obtained, for example, by a transesterification reaction between dimethyl oxalate and ethylene glycol or butanediol.
- R 2 is a divalent cyclic group containing an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring, for example, a benzene ring group, a naphthalene ring group, a cyclohexane ring group, particularly a p-phenylene group, or methylene
- An alkylene group such as ethylene
- the weight average molecular weight Mw of such polyoxalate is in the range of 5,000 to 200,000, particularly 5,000 to 100,000. Is desirable.
- the chelating agent used in the present invention is a multidentate ligand that coordinates to a metal ion to form a chelate compound.
- the chelating agent is particularly used for capturing Ca ions.
- Such a chelating agent is not particularly limited as long as it reacts with Ca ions to produce a water-soluble chelate compound, but water-soluble crystal powder or liquid product is particularly preferably used.
- Resins or fibrous chelating agents are also known, but these are not suitable because they can remain in water and cause clogging of cracks.
- chelating agents for crystal powder or liquid products polymerized phosphate (inorganic), aminocarboxylic acid (organic), phosphonic acid chelating agents, and aspartic acid chelating agents are known. Yes.
- any type of chelating agent can be used, but aminocarboxylic, phosphonic and aspartic chelates in that they are chemically stable and do not adversely affect the environment. Agents are preferably used.
- aminocarboxylic acid-based chelating agents include ethylenediaminetetraacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, dicarboxymethylglutamic acid, 2-carboxyphenyliminodiacetic acid, S, S-ethylenediamine.
- Disuccinic acid methylglycine diacetic acid, 1,2-cyclohexanediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid (HEDTA), dihydroxyethylethylenediaminetetraacetic acid (DHEDDA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraamine hexaacetic acid (TTHA) and the like.
- HEDTA hydroxyethylethylenediaminetriacetic acid
- DHEDDA dihydroxyethylethylenediaminetetraacetic acid
- DTPA diethylenetriaminepentaacetic acid
- TTHA triethylenetetraamine hexaacetic acid
- phosphonic acid chelating agents include amino trimethylene phosphonic acid (NTMP), hydroxyethane diphosphonic acid (HEDP), phosphonobutane tricarboxylic acid (PBTC), and ethylenediaminetetramethylene phosphonic acid (EDTMP). Can
- aspartic acid chelating agent examples include L-aspartic acid diacetic acid (ADSA).
- ADSA L-aspartic acid diacetic acid
- EDTA ethylenediaminetetraacetic acid
- the above chelating agent reacts at 1: 1 regardless of the valence of the ion and binds to the metal ion to form a stable chelate compound. Therefore, such a chelating agent has the following formula in order to completely capture Ca ions: X ⁇ Y Where X is the molar amount of the chelating agent, Y is the molar amount of Ca ions present in the water, It is preferable to use it in an amount satisfying. In addition, since the amount of Ca ions eluted in the water injected into the well is usually about 1000 ppm at most, it is desirable to use this chelating agent in excess with this amount as clear. Furthermore, other polyvalent metals can be captured by using an excessive amount of a chelating agent. Thereby, the production
- the oxalic acid scavenger used in the present invention is a water-soluble compound that reacts quickly with oxalic acid or oxalate (particularly calcium oxalate) to form a water-soluble oxalic acid derivative compound.
- a metal compound that reacts with oxalic acid to form a water-soluble salt in preference to Ca can be used.
- the metal of such a compound include metals having a lower ionization tendency than K, Ca, Na and Mg.
- K, Na, and Mg reacts with oxalic acid to form a salt, it ion-exchanges with Ca to generate calcium oxalate, and does not react with the generated calcium oxalate. Therefore, it is not suitable as an oxalic acid scavenger.
- examples of the Al compound used as the oxalic acid scavenger include Al salts of various organic acids and Al salts of inorganic acids (for example, aluminum sulfate, aluminum chloride, aluminum nitrate, etc.).
- the Al salt may react with Ca or Ca ions present in water to produce a water-insoluble Ca salt, or may produce chlorides that are undesirable for the environment. Therefore, an Al compound suitable as an oxalic acid scavenger is most preferably an Al salt of an organic acid or an Al salt of an inorganic acid, such as aluminum lactate or aluminum chloride.
- the oxalic acid scavenger used in the present invention is present in the water into which polyoxalate is added so that it can effectively suppress the formation of calcium oxalate by reacting with Ca ions present in the water. It is used in an appropriate amount depending on the amount of Ca ions present. Generally, the amount of Ca per total amount (M + Ca) of Ca ions present in water and metal M (for example, Al) in the oxalic acid scavenger is 80 mol% or less, preferably 55 mol% or less, most preferably It is preferable to use an oxalic acid scavenger so that is 25 mol% or less.
- ⁇ Hydrolysis of polyoxalate> hydrolysis of polyoxalate in the presence of a chelating agent is performed at an underground temperature where cracks are generated by, for example, hydraulic fracturing, and particularly excellent hydrolysis of polyoxalate at low temperatures.
- the polyoxalate and the chelating agent can be mixed on the ground with the polyoxalate pellets and the chelating agent, and can be press-fitted into the well, or the polyoxalate and the chelating agent. It is also possible to prepare an aqueous solution containing the mixture with the surface and press-fit the aqueous solution into the well. Further, when the chelating agent is in the form of crystal powder, a flow path control agent in which polyoxalate and chelating agent are mixed is prepared in advance, and the flow path control agent is added to the mesh particle size (residual screen particle size).
- the chelating agent can be coated or encapsulated with a material that dissolves in pH, temperature, or water, and can be press-fitted. In such a flow path control agent, it is necessary to contain a chelating agent in excess of the amount of Ca ions present in water (or the upper limit of the amount of Ca ions normally present).
- the pH of water into which the polyoxalate and chelating agent are added should be adjusted to a predetermined range. is required. For example, when EDTA is used, the pH is adjusted to 5 or more by adding an alkali or the like.
- a crack support material such as proppant (sand etc.) used so that cracks do not collapse due to underground pressure can be supplied to the water in the well where the polyoxalate and the chelating agent are added.
- guar gum, xanthone, or the like can be added as a thickening agent so that cracks are rapidly generated by pressurization.
- underground temperature hydrolysis temperature
- Scale inhibitors such as acids and inorganic phosphoric acids can also be used.
- hydrolysis of polyoxalate using an oxalic acid scavenger is carried out at an underground temperature where cracks are generated by, for example, hydraulic fracturing, and particularly excellent hydrolyzability of polyoxalate at low temperatures.
- an underground temperature of 30 to 70 ° C, particularly 30 to 50 ° C. That is, the present invention is preferably applied to sampling of shale gas having such underground temperature.
- the polyoxalate and the oxalic acid scavenger can be mixed on the ground with the pellets of the polyoxalate and the oxalic acid scavenger and pressed into the well, or the mixture of the polyoxalate and the oxalic acid scavenger It is also possible to prepare an aqueous solution containing it on the surface and press-fit this aqueous solution into the well. Further, a flow path control agent in which polyoxalate and an oxalic acid scavenger are mixed is prepared in advance, and the flow path control agent is made of a granular material or powder having a mesh particle size (residual screen particle size) of 5000 ⁇ m or less.
- the oxalic acid scavenger may be coated or encapsulated with a material that dissolves in pH, temperature, or water, and then injected.
- a flow path control agent preferably contains 10 parts by mass or more, particularly about 15 to 100 parts by mass of the oxalic acid scavenger per 100 parts by mass of the polyoxalate.
- the amount of Ca ions present in the well is at most about 1000 ppm, when the oxalic acid scavenger is blended in such an amount, when the oxalic acid scavenger is injected into the water in the well, the oxalic acid scavenger
- the amount of Ca with respect to Ca is equal to or greater than the above-described range, so that the formation of calcium oxalate can be constantly suppressed and crack closure due to calcium oxalate can be effectively avoided.
- a crack support material such as proppant (sand etc.) used to prevent cracks from collapsing due to underground pressure can be supplied to the well water to which polyoxalate and oxalic acid scavenger are added. it can.
- guar gum, xanthone, or the like can be added as a thickening agent so that cracks are rapidly generated by pressurization.
- underground temperature hydrolysis temperature
- a chelating agent that reacts with calcium ions a calcium oxalate aggregation inhibitor, a calcium oxalate precipitation inhibitor, and a low molecular weight polymer having a carboxyl group that has a calcium oxalate crystal growth inhibitory effect.
- Scale inhibitors such as phosphonic acid and inorganic phosphoric acid can also be used.
- the above-described method for hydrolyzing polyoxalate according to the present invention can make effective use of the excellent hydrolysis performance to effectively generate cracks by pressurizing the fracturing fluid. Moreover, the operation
- the obtained PEOx had a melting point of 165 ° C. and a weight average molecular weight Mw of 100,000.
- Salting out amount (%) 100 ⁇ (residual weight) / (theoretical salting out amount)
- Theoretical salting-out amount (g) charged polyoxalate (mol) ⁇ Calcium oxalate molecular weight (g / mol)
- EDTA ethylenediaminetetraacetic acid: manufactured by Wako Pure Chemical Industries, Ltd.
- EDTA ethylenediaminetetraacetic acid: manufactured by Wako Pure Chemical Industries, Ltd.
- Tris-HCl buffer pH 9.0
- 10 ml pH adjuster
- a liquid and B liquid were prepared.
- Liquid A 1% calcium chloride aqueous solution
- B liquid 1% aluminum lactate aqueous solution
- C liquid 1% aluminum chloride aqueous solution
- Table 2 3 ml of 1% oxalic acid aqueous solution was added thereto and heated in an oven at 70 ° C. for 2 hours. The supernatant was discarded and dried at 90 ° C. for 5 hours, and the amount of precipitate was measured. The results are shown in Table 2. Moreover, it is a graph which shows the amount of Ca with respect to the precipitation amount of calcium oxalate, and Al.
Abstract
The present invention provides a method for decomposing a polyoxalate, which hydrolyzes a polyoxalate in water, and which is characterized by promoting the hydrolysis of the polyoxalate by having a chelating agent for trapping Ca ions or an oxalic acid trapping agent coexistent in the water, said oxalic acid trapping agent being reactive with oxalic acid or an oxalic acid salt.
Description
本発明は、水中でポリオキサレートを加水分解するポリオキサレートの分解方法に関するものであり、より詳細には、石油、天然ガス、シェールガスなどの地下資源を、水圧破砕法を利用して採取する際に、流路制御剤（ｄｉｖｅｒｔｉｎｇ ａｇｅｎｔ）として使用されるポリオキサレートを加水分解する方法に関する。
The present invention relates to a polyoxalate decomposition method that hydrolyzes polyoxalate in water, and more specifically, underground resources such as petroleum, natural gas, and shale gas are collected using a hydraulic fracturing method. The present invention relates to a method of hydrolyzing a polyoxalate used as a flow path controlling agent.
地下資源の採取のために、水圧破砕法を用いた手法が広く採用されている。この手法では、例えば、特許文献１にも開示されているように、まず、ドリル等による掘削により形成された坑井を、流体で満たす。次いで、この流体を加圧することにより、坑井から亀裂を生成させる。そして、この亀裂を通して、石油（オイル）やガスなどの地下資源を採取するというものである。かかる方法は、水圧破砕法とも呼ばれ、この方法で使用される流体は、フラクチュアリング流体とも呼ばれる。
このような手法によれば、亀裂の生成により、坑井の資源流入断面が著しく増大し、効率よく地下資源の採取を行うことができる。特に、比較的地中の浅い堆積層から産出するシェールガスの採掘などに広く適用されている。 The technique using the hydraulic fracturing method is widely adopted to collect underground resources. In this method, for example, as disclosed inPatent Document 1, first, a well formed by excavation with a drill or the like is filled with a fluid. The fluid is then pressurized to generate a crack from the well. Through this crack, underground resources such as oil and gas are collected. Such a method is also called a hydraulic fracturing method, and the fluid used in this method is also called a fracturing fluid.
According to such a technique, the generation of cracks significantly increases the cross section of the well's resource inflow, and the underground resource can be efficiently collected. In particular, it is widely applied to mining of shale gas produced from a relatively shallow underground layer.
このような手法によれば、亀裂の生成により、坑井の資源流入断面が著しく増大し、効率よく地下資源の採取を行うことができる。特に、比較的地中の浅い堆積層から産出するシェールガスの採掘などに広く適用されている。 The technique using the hydraulic fracturing method is widely adopted to collect underground resources. In this method, for example, as disclosed in
According to such a technique, the generation of cracks significantly increases the cross section of the well's resource inflow, and the underground resource can be efficiently collected. In particular, it is widely applied to mining of shale gas produced from a relatively shallow underground layer.
ところで、上記の水圧破砕法においては、流体加圧による亀裂の生成に先立って、水平坑井中でパーポレーションと呼ばれる予備爆破が行われる。このような予備爆破により、この坑井の深部に比較的大きな亀裂と共に、多数の小さな亀裂が生成する。この後、この坑井内にフラクチュアリング流体を圧入することにより、これら亀裂に流体が流入する。その結果、これら亀裂に負荷が加えられ、資源の採取に好適な大きさ亀裂に成長していくこととなる。
By the way, in the hydraulic fracturing method described above, a preliminary blast called perporation is performed in a horizontal well prior to the generation of cracks due to fluid pressurization. Such preliminary blasting produces a large number of small cracks along with relatively large cracks in the deep part of the well. Thereafter, the fluid flows into these cracks by press-fitting the fracture fluid into the well. As a result, a load is applied to these cracks, and the cracks grow to a size suitable for resource collection.
フラクチュアリング流体を用いて、このように亀裂を生成させ、この亀裂を通して資源ガスを採取する水圧破砕法には、この亀裂を一時的に塞ぐ加水分解性材料が使用されることがある。
In a hydraulic fracturing method in which a crack is generated using a fracturing fluid and resource gas is collected through the crack, a hydrolyzable material that temporarily closes the crack may be used.
例えば、既に生成している亀裂の一部を一時的に塞ぐ流路制御剤（ｄｉｖｅｒｔｉｎｇ ａｇｅｎｔ）が使用されることがある。この流路制御剤は、目止材と呼ばれることもある。即ち、既に形成されている亀裂の一部を流路制御剤で閉塞しておき、この状態で坑井内に充填された流体を加圧することにより、他の亀裂内に流体が侵入する。これにより、該亀裂が大きく成長していくこととなり、多くの大きな亀裂を効果的に生成することができるわけである。このような流路制御剤としては、加水分解性材料が使用される。亀裂を一時的に塞ぐものであり、経時により分解する性質を有していることが必要であるからである。
特許文献１及び２には、この流路制御剤として、ポリ乳酸粉末やポリ乳酸の繊維状物を使用することが開示されている。このような流路制御剤は、経時と共に加水分解して消失するため、地中に残存することによる環境汚染を有効に防止することができる。また、資源であるガスやオイルの採取を阻害することもない。 For example, a diverting agent that temporarily closes a part of a crack that has already been generated may be used. This flow path control agent is sometimes called a sealing material. That is, a part of the crack that has already been formed is closed with a flow path control agent, and the fluid filled in the well is pressurized in this state, so that the fluid enters the other crack. Thereby, the crack grows greatly, and many large cracks can be generated effectively. A hydrolyzable material is used as such a flow path control agent. This is because it is necessary to temporarily close the crack and to have a property of decomposing with time.
Patent Documents 1 and 2 disclose using polylactic acid powder or polylactic acid fibrous materials as the flow path control agent. Since such a flow path control agent hydrolyzes and disappears with time, environmental pollution due to remaining in the ground can be effectively prevented. Moreover, it does not hinder the collection of gas and oil as resources.
特許文献１及び２には、この流路制御剤として、ポリ乳酸粉末やポリ乳酸の繊維状物を使用することが開示されている。このような流路制御剤は、経時と共に加水分解して消失するため、地中に残存することによる環境汚染を有効に防止することができる。また、資源であるガスやオイルの採取を阻害することもない。 For example, a diverting agent that temporarily closes a part of a crack that has already been generated may be used. This flow path control agent is sometimes called a sealing material. That is, a part of the crack that has already been formed is closed with a flow path control agent, and the fluid filled in the well is pressurized in this state, so that the fluid enters the other crack. Thereby, the crack grows greatly, and many large cracks can be generated effectively. A hydrolyzable material is used as such a flow path control agent. This is because it is necessary to temporarily close the crack and to have a property of decomposing with time.
また、ポリオキサレート（或いはポリオキサレート共重合体）は、ポリ乳酸よりも加水分解性が高く、低温での加水分解速度が速い。さらには、ポリ乳酸の加水分解を促進する加水分解促進剤としての特性も有している。このため、かかるポリオキサレートについて、特許文献３～５には、ポリ乳酸と共に、或いはそれ単独で、流路制御剤としての使用が本出願人により提案されている。
Also, polyoxalate (or polyoxalate copolymer) is more hydrolyzable than polylactic acid and has a faster hydrolysis rate at low temperatures. Furthermore, it has the characteristic as a hydrolysis promoter which accelerates | stimulates hydrolysis of polylactic acid. For this reason, Patent Documents 3 to 5 propose the use of such polyoxalate together with polylactic acid or alone as a flow path control agent by the present applicant.
ところで、ポリオキサレートは、確かにポリ乳酸よりも加水分解性に優れ、また、ポリ乳酸の加水分解を促進するという機能も有しており、流路制御剤としての実用化が期待されるのであるが、ポリオキサレートが添加される水の水質によっては、その加水分解性による利点が十分に発揮されないことがあった。即ち、流路制御剤は、フラクチュアリング流体を用いての加圧によって既に坑井内に生成している亀裂内に侵入し、該亀裂を閉塞するため、次の亀裂発生のための加圧を効果的にすることができる。また、該次の亀裂発生のための加圧に際しては、既に生成している亀裂の崩壊を防止することができる。さらに、ガス回収のために効果的な数の亀裂を発生させた後は、流路制御剤は加水分解して閉塞していた亀裂を開放する。
ポリオキサレートを流路制御剤として用いた場合、この亀裂の開放が十分に行われず、亀裂が固体粒子により閉じられているという不都合をしばしば生じ、その実用化が妨げられているのが実情である。 By the way, polyoxalate is surely superior in hydrolyzability than polylactic acid, and also has a function of promoting hydrolysis of polylactic acid, and is expected to be put into practical use as a flow path control agent. However, depending on the water quality of the water to which the polyoxalate is added, the hydrolyzable advantage may not be fully exhibited. That is, the flow path control agent penetrates into the crack already generated in the well by pressurization using the fracturing fluid and closes the crack. Can be effective. Further, in the pressurization for the next generation of cracks, it is possible to prevent the cracks already generated from collapsing. Further, after generating an effective number of cracks for gas recovery, the flow path control agent hydrolyzes to open the closed cracks.
When polyoxalate is used as a flow path control agent, the cracks are not sufficiently opened, often resulting in inconvenience that the cracks are closed by solid particles, impeding its practical use. is there.
ポリオキサレートを流路制御剤として用いた場合、この亀裂の開放が十分に行われず、亀裂が固体粒子により閉じられているという不都合をしばしば生じ、その実用化が妨げられているのが実情である。 By the way, polyoxalate is surely superior in hydrolyzability than polylactic acid, and also has a function of promoting hydrolysis of polylactic acid, and is expected to be put into practical use as a flow path control agent. However, depending on the water quality of the water to which the polyoxalate is added, the hydrolyzable advantage may not be fully exhibited. That is, the flow path control agent penetrates into the crack already generated in the well by pressurization using the fracturing fluid and closes the crack. Can be effective. Further, in the pressurization for the next generation of cracks, it is possible to prevent the cracks already generated from collapsing. Further, after generating an effective number of cracks for gas recovery, the flow path control agent hydrolyzes to open the closed cracks.
When polyoxalate is used as a flow path control agent, the cracks are not sufficiently opened, often resulting in inconvenience that the cracks are closed by solid particles, impeding its practical use. is there.
従って、本発明の目的は、亀裂を閉じるような固体粒子の生成を生じることなく、ポリオキサレートの加水分解を行うポリオキサレート分解方法を提供することにある。
本発明の他の目的は、フラクチュアリング流体を用いての水圧破砕法による天然資源採掘のための亀裂生成に際して、好適に使用される流路制御剤を提供することにある。 Accordingly, an object of the present invention is to provide a polyoxalate decomposition method in which polyoxalate is hydrolyzed without producing solid particles that close cracks.
Another object of the present invention is to provide a flow path control agent that is suitably used when generating cracks for natural resource mining by hydraulic fracturing using a fracturing fluid.
本発明の他の目的は、フラクチュアリング流体を用いての水圧破砕法による天然資源採掘のための亀裂生成に際して、好適に使用される流路制御剤を提供することにある。 Accordingly, an object of the present invention is to provide a polyoxalate decomposition method in which polyoxalate is hydrolyzed without producing solid particles that close cracks.
Another object of the present invention is to provide a flow path control agent that is suitably used when generating cracks for natural resource mining by hydraulic fracturing using a fracturing fluid.
本発明者等は、水中でのポリオキサレートの加水分解について多くの実験を行い検討した結果、水中にＣａが存在していた場合、ポリオキサレートの加水分解により生成するシュウ酸カルシウムが亀裂を閉塞する粒子の要因であることを見出し、本発明を完成させるに至った。
The present inventors have conducted many experiments on the hydrolysis of polyoxalate in water, and as a result, when Ca is present in water, the calcium oxalate produced by the hydrolysis of polyoxalate cracks. The present inventors have found that this is a cause of clogging particles and have completed the present invention.
即ち、本発明によれば、水中でポリオキサレートを加水分解するポリオキサレート分解方法において、
前記水中に、Ｃａイオンを捕捉するためのキレート剤、またはシュウ酸もしくはシュウ酸塩と反応性を有するシュウ酸捕捉剤を、共存させてポリオキサレートの加水分解を促進させることを特徴とするポリオキサレート分解方法が提供される。 That is, according to the present invention, in the polyoxalate decomposition method of hydrolyzing polyoxalate in water,
A polychelate that promotes hydrolysis of polyoxalate by coexisting a chelating agent for capturing Ca ions or an oxalic acid scavenger reactive with oxalic acid or oxalate in the water. An oxalate decomposition method is provided.
前記水中に、Ｃａイオンを捕捉するためのキレート剤、またはシュウ酸もしくはシュウ酸塩と反応性を有するシュウ酸捕捉剤を、共存させてポリオキサレートの加水分解を促進させることを特徴とするポリオキサレート分解方法が提供される。 That is, according to the present invention, in the polyoxalate decomposition method of hydrolyzing polyoxalate in water,
A polychelate that promotes hydrolysis of polyoxalate by coexisting a chelating agent for capturing Ca ions or an oxalic acid scavenger reactive with oxalic acid or oxalate in the water. An oxalate decomposition method is provided.
本発明のポリオキサレート分解方法においては、
（１）前記水中にＣａイオンが存在しており、前記キレート剤を、下記式；
Ｘ≧Ｙ
式中、Ｘは前記キレート剤のモル量であり、
Ｙは、前記水中に存在するＣａイオンのモル量である、
で表される条件を満足する量で使用すること、
（２）前記キレート剤がアミノカルボン酸系キレート剤、及びホスホン酸系キレート剤、及びアスパラギン酸系キレート剤の何れかであること、
（３）ｐＨが５以上に調整された水中に、前記ポリオキサレートおよびキレート剤を存在させること、
（４）前記シュウ酸捕捉剤がＡｌ及びＡｌ化合物の何れかであること、
（５）前記Ａｌ化合物が乳酸アルミニウムであること、
が好適である。 In the polyoxalate decomposition method of the present invention,
(1) Ca ions are present in the water, and the chelating agent is represented by the following formula:
X ≧ Y
Where X is the molar amount of the chelating agent,
Y is the molar amount of Ca ions present in the water,
Used in an amount that satisfies the conditions expressed by
(2) The chelating agent is any one of an aminocarboxylic acid chelating agent, a phosphonic acid chelating agent, and an aspartic acid chelating agent,
(3) The presence of the polyoxalate and the chelating agent in water whose pH is adjusted to 5 or higher,
(4) The oxalic acid scavenger is either Al or an Al compound,
(5) The Al compound is aluminum lactate,
Is preferred.
（１）前記水中にＣａイオンが存在しており、前記キレート剤を、下記式；
Ｘ≧Ｙ
式中、Ｘは前記キレート剤のモル量であり、
Ｙは、前記水中に存在するＣａイオンのモル量である、
で表される条件を満足する量で使用すること、
（２）前記キレート剤がアミノカルボン酸系キレート剤、及びホスホン酸系キレート剤、及びアスパラギン酸系キレート剤の何れかであること、
（３）ｐＨが５以上に調整された水中に、前記ポリオキサレートおよびキレート剤を存在させること、
（４）前記シュウ酸捕捉剤がＡｌ及びＡｌ化合物の何れかであること、
（５）前記Ａｌ化合物が乳酸アルミニウムであること、
が好適である。 In the polyoxalate decomposition method of the present invention,
(1) Ca ions are present in the water, and the chelating agent is represented by the following formula:
X ≧ Y
Where X is the molar amount of the chelating agent,
Y is the molar amount of Ca ions present in the water,
Used in an amount that satisfies the conditions expressed by
(2) The chelating agent is any one of an aminocarboxylic acid chelating agent, a phosphonic acid chelating agent, and an aspartic acid chelating agent,
(3) The presence of the polyoxalate and the chelating agent in water whose pH is adjusted to 5 or higher,
(4) The oxalic acid scavenger is either Al or an Al compound,
(5) The Al compound is aluminum lactate,
Is preferred.
本発明によれば、さらに、ポリオキサレートとシュウ酸捕捉剤とからなる流路制御剤が提供される。
かかる流路制御剤においては、前記シュウ酸捕捉剤としてＡｌ化合物、特に乳酸アルミニウムが好適に使用される。 The present invention further provides a flow path control agent comprising a polyoxalate and an oxalic acid scavenger.
In such a flow path control agent, an Al compound, particularly aluminum lactate, is preferably used as the oxalic acid scavenger.
かかる流路制御剤においては、前記シュウ酸捕捉剤としてＡｌ化合物、特に乳酸アルミニウムが好適に使用される。 The present invention further provides a flow path control agent comprising a polyoxalate and an oxalic acid scavenger.
In such a flow path control agent, an Al compound, particularly aluminum lactate, is preferably used as the oxalic acid scavenger.
本発明のポリオキサレート分解方法では、このポリオキサレートの加水分解が行われる水中に、キレート剤を共存させておくという手段が採用される。
即ち、ポリオキサレートは、加水分解によりシュウ酸とアルコールとを生成するが、加水分解により生成したシュウ酸が水中に存在するＣａ（特にＣａイオン）と反応してシュウ酸カルシウムが生じる。このシュウ酸カルシウムは、結晶粒子として析出し、この粒子が要因となり、水圧破砕により形成した亀裂中に残ることとなる。その結果として、亀裂からの地下資源（例えばシェールガスや天然ガス）の採取が困難となってしまう。
しかるに、本発明では、水中にキレート剤を共存させているため、水中に存在するＣａイオンがキレート剤に捕捉されて錯塩を形成するため、シュウ酸カルシウムの生成が抑制される。その結果、水圧破砕により形成した亀裂が閉塞してしまうという不都合を有効に防止することができる。 In the polyoxalate decomposition method of the present invention, a means of allowing a chelating agent to coexist in water in which the polyoxalate is hydrolyzed is employed.
That is, polyoxalate produces oxalic acid and alcohol by hydrolysis, but oxalic acid produced by hydrolysis reacts with Ca (particularly Ca ions) present in water to produce calcium oxalate. This calcium oxalate precipitates as crystal particles, and these particles are a factor and remain in cracks formed by hydraulic crushing. As a result, it becomes difficult to collect underground resources (for example, shale gas and natural gas) from the crack.
However, in the present invention, since a chelating agent is allowed to coexist in water, Ca ions existing in water are trapped by the chelating agent to form a complex salt, so that the production of calcium oxalate is suppressed. As a result, it is possible to effectively prevent the inconvenience that a crack formed by hydraulic crushing is blocked.
即ち、ポリオキサレートは、加水分解によりシュウ酸とアルコールとを生成するが、加水分解により生成したシュウ酸が水中に存在するＣａ（特にＣａイオン）と反応してシュウ酸カルシウムが生じる。このシュウ酸カルシウムは、結晶粒子として析出し、この粒子が要因となり、水圧破砕により形成した亀裂中に残ることとなる。その結果として、亀裂からの地下資源（例えばシェールガスや天然ガス）の採取が困難となってしまう。
しかるに、本発明では、水中にキレート剤を共存させているため、水中に存在するＣａイオンがキレート剤に捕捉されて錯塩を形成するため、シュウ酸カルシウムの生成が抑制される。その結果、水圧破砕により形成した亀裂が閉塞してしまうという不都合を有効に防止することができる。 In the polyoxalate decomposition method of the present invention, a means of allowing a chelating agent to coexist in water in which the polyoxalate is hydrolyzed is employed.
That is, polyoxalate produces oxalic acid and alcohol by hydrolysis, but oxalic acid produced by hydrolysis reacts with Ca (particularly Ca ions) present in water to produce calcium oxalate. This calcium oxalate precipitates as crystal particles, and these particles are a factor and remain in cracks formed by hydraulic crushing. As a result, it becomes difficult to collect underground resources (for example, shale gas and natural gas) from the crack.
However, in the present invention, since a chelating agent is allowed to coexist in water, Ca ions existing in water are trapped by the chelating agent to form a complex salt, so that the production of calcium oxalate is suppressed. As a result, it is possible to effectively prevent the inconvenience that a crack formed by hydraulic crushing is blocked.
また、本発明のポリオキサレート分解方法では、上記のようにシュウ酸カルシウムの析出を抑制することで、水圧破砕法を用いた地下資源の採取の効率化を図ることを目的としている。また、シュウ酸カルシウムの析出を抑制する手段として、例えば、シュウ酸またはシュウ酸塩を捕捉することよっても本発明の目的を達成できる。即ち、本発明のポリオキサレート分解方法では、このポリオキサレートの加水分解が行われる水中に、シュウ酸もしくはシュウ酸塩と反応性を有するシュウ酸捕捉剤を共存させておくという手段が採用される。
これにより、ポリオキサレートの加水分解により生成したシュウ酸が速やかにシュウ酸捕捉剤と反応して水溶性塩を形成する。その結果、シュウ酸カルシウムの生成が抑制され、水圧破砕により形成した亀裂の閉塞を有効に防止できる。 Further, the polyoxalate decomposition method of the present invention aims to improve the efficiency of collecting underground resources using the hydraulic crushing method by suppressing the precipitation of calcium oxalate as described above. In addition, as a means for suppressing the precipitation of calcium oxalate, for example, the object of the present invention can be achieved by capturing oxalic acid or oxalate. That is, in the polyoxalate decomposition method of the present invention, a means is adopted in which an oxalic acid scavenger reactive with oxalic acid or oxalate coexists in water in which the polyoxalate is hydrolyzed. The
Thereby, the oxalic acid produced | generated by the hydrolysis of polyoxalate reacts with an oxalic-acid capture | acquisition agent rapidly, and forms water-soluble salt. As a result, the production of calcium oxalate is suppressed, and it is possible to effectively prevent clogging of cracks formed by hydraulic crushing.
これにより、ポリオキサレートの加水分解により生成したシュウ酸が速やかにシュウ酸捕捉剤と反応して水溶性塩を形成する。その結果、シュウ酸カルシウムの生成が抑制され、水圧破砕により形成した亀裂の閉塞を有効に防止できる。 Further, the polyoxalate decomposition method of the present invention aims to improve the efficiency of collecting underground resources using the hydraulic crushing method by suppressing the precipitation of calcium oxalate as described above. In addition, as a means for suppressing the precipitation of calcium oxalate, for example, the object of the present invention can be achieved by capturing oxalic acid or oxalate. That is, in the polyoxalate decomposition method of the present invention, a means is adopted in which an oxalic acid scavenger reactive with oxalic acid or oxalate coexists in water in which the polyoxalate is hydrolyzed. The
Thereby, the oxalic acid produced | generated by the hydrolysis of polyoxalate reacts with an oxalic-acid capture | acquisition agent rapidly, and forms water-soluble salt. As a result, the production of calcium oxalate is suppressed, and it is possible to effectively prevent clogging of cracks formed by hydraulic crushing.
＜亀裂生成の原理＞
流体（フラクチュアリング流体）を用いての資源の採掘に際しては、図１に示されているように、ドリル等により掘削された水平方向に延びている坑井１の深部で予備爆破（パーポレーション）が行われ、これにより、大きな亀裂３ａと、小さな亀裂３ｂが形成される（図１（ａ）参照）。
大きな亀裂３ａは、そのまま、資源の採取に利用できるが、その数は少なく、大量の資源を効率よく採取するには十分ではない。このため、さらに大きな亀裂を形成する作業が行われることとなる。 <Principle of crack generation>
When mining resources using a fluid (fracturing fluid), as shown in FIG. 1, a preliminary blast (perpendicular) is carried out in the deep portion of thewell 1 that is drilled by a drill or the like and extends in the horizontal direction. Thus, a large crack 3a and a small crack 3b are formed (see FIG. 1A).
Thelarge cracks 3a can be used for collecting resources as they are, but the number thereof is small and it is not sufficient for efficiently collecting a large amount of resources. For this reason, the operation | work which forms a bigger crack will be performed.
流体（フラクチュアリング流体）を用いての資源の採掘に際しては、図１に示されているように、ドリル等により掘削された水平方向に延びている坑井１の深部で予備爆破（パーポレーション）が行われ、これにより、大きな亀裂３ａと、小さな亀裂３ｂが形成される（図１（ａ）参照）。
大きな亀裂３ａは、そのまま、資源の採取に利用できるが、その数は少なく、大量の資源を効率よく採取するには十分ではない。このため、さらに大きな亀裂を形成する作業が行われることとなる。 <Principle of crack generation>
When mining resources using a fluid (fracturing fluid), as shown in FIG. 1, a preliminary blast (perpendicular) is carried out in the deep portion of the
The
さらなる亀裂の生成は、通常、上記亀裂３ａを一時的に塞いでおき、流体（フラクチュアリング流体）を坑井内に圧入することにより行われる。この亀裂３ａを塞いでおかないと、流体を圧入した時、流体が大きな亀裂３ａ内に流入するため、他の部分に流体圧が効果的に加わらない。また、亀裂３ａから資源となるガスが流出してくることもあり、このガス圧によって流体の圧入が阻害されることがある。これらを防止すために、流体の圧入に際しては、亀裂３ａを一時的に塞いでおく必要があるわけである。
Further generation of cracks is usually performed by temporarily closing the crack 3a and press-fitting a fluid (fracturing fluid) into the well. Unless the crack 3a is closed, the fluid flows into the large crack 3a when the fluid is press-fitted, so that the fluid pressure is not effectively applied to other portions. Moreover, the gas which becomes a resource may flow out from the crack 3a, and the press-fitting of the fluid may be hindered by this gas pressure. In order to prevent these problems, it is necessary to temporarily close the crack 3a when the fluid is injected.
亀裂３ａを一時的に塞ぐためには、流路制御剤（ｄｉｖｅｒｔｉｎｇ ａｇｅｎｔ）５が使用される。この流路制御剤５としては、加水分解性樹脂の粉末や繊維状物などが使用される。このような流路制御剤５は、通常、坑井内に圧入する流体に添加される。この流体を坑井内に圧入すると、大きな亀裂３ａ内に流路制御剤５が侵入し、これにより、大きな亀裂３ａが閉じられることとなる（図１（ｂ）参照）。
In order to temporarily close the crack 3a, a diverting agent 5 is used. As the flow path control agent 5, a hydrolyzable resin powder or a fibrous material is used. Such a flow path control agent 5 is normally added to the fluid press-fitted into the well. When this fluid is press-fitted into the well, the flow path control agent 5 enters the large crack 3a, thereby closing the large crack 3a (see FIG. 1B).
このようにして亀裂３ａを閉じることにより、この亀裂３ａ内に加圧流体が流入することや、亀裂３ａからのガスが流出することが防止される。従って、流体の圧入を引き続いて行うことにより、流体圧が大きな亀裂３ａ以外の部分に効果的に作用する。例えば、初めの予備爆破の際に生成した小さな亀裂３ｂに大きな流体圧が加わり、この亀裂３ｂが大きく成長していくこととなり、これにより、坑井１の全体にわたって、資源の採取に適当な大きさの亀裂３ａを形成することができるわけである。
By closing the crack 3a in this way, it is possible to prevent the pressurized fluid from flowing into the crack 3a and the gas from the crack 3a from flowing out. Therefore, by continuing the fluid press-fitting, the fluid pressure effectively acts on the portion other than the crack 3a. For example, a large fluid pressure is applied to the small crack 3b generated at the time of the first preliminary blasting, and the crack 3b grows greatly, so that the whole well 1 has a suitable size for collecting resources. Thus, the crack 3a can be formed.
上記のようにして大きな亀裂３ａを形成した後は、上記の流路制御剤５は分解し、閉じられた亀裂３ａを開放する必要がある。上述したように、この亀裂３ａを通して、シェールガスや天然ガスが採取されるからである。このため、このような流路制御剤５としては加水分解樹脂の粉末等が使用されるわけである。
After the large crack 3a is formed as described above, the flow path control agent 5 needs to be decomposed to open the closed crack 3a. This is because shale gas and natural gas are collected through the crack 3a as described above. For this reason, as the flow path control agent 5, hydrolyzed resin powder or the like is used.
ところで、ポリオキサレートは、低温での加水分解性に優れている。例えばポリ乳酸等と比較しても、５０℃以下の温度での加水分解性が優れているため、流路制御剤５としての使用が提案されている。シェールガスのように、比較的浅い地層に存在しているガスを採取するには、特に５０℃以下の温度で適度な加水分解性を示し、水圧破砕により亀裂３ａを形成した後は、できるだけ速やかに分解して消失することが必要であり、ポリオキサレートは、このような要求特性を満足しているからである。
By the way, polyoxalate is excellent in hydrolyzability at low temperature. For example, compared with polylactic acid or the like, it is excellent in hydrolyzability at a temperature of 50 ° C. or lower, and therefore has been proposed for use as the flow path control agent 5. In order to collect a gas existing in a relatively shallow formation such as shale gas, it exhibits moderate hydrolyzability particularly at a temperature of 50 ° C. or less, and as soon as possible after forming the crack 3a by hydraulic fracturing. This is because the polyoxalate satisfies such required characteristics.
しかしながら、ポリオキサレートを、純水中で加水分解する場合には全く問題が生じないのであるが、地中に形成された坑井中に圧入された水中で加水分解せしめる場合には、予想外の不都合を生じることが判った。
即ち、地中には、石灰に代表されるように、Ｃａ化合物が多く分布しており、構成内に圧入された水には、Ｃａイオンが溶出している場合が多い。このように水中にＣａイオンが存在している状態でポリオキサレートが加水分解すると、ポリオキサレートの加水分解により生じたシュウ酸がＣａと反応してシュウ酸カルシウムが生成する。さらに、経時と共に、シュウ酸カルシウムの結晶が析出し、この結晶粒子により亀裂３ａが閉じられてしまうという不都合を生じる。要するに、流路制御剤５であるポリオキサレートが加水分解せずに、亀裂３ａ内にそのまま残存しているとの同じこととなってしまい、ポリオキサレートの優れた加水分解性が全く活かされないのである。 However, there is no problem when polyoxalate is hydrolyzed in pure water, but it is unexpected when hydrolyzed in water injected into a well formed in the ground. It turned out to be inconvenient.
That is, as represented by lime, a large amount of Ca compound is distributed in the ground, and in many cases, Ca ions are eluted in the water injected into the structure. Thus, when polyoxalate is hydrolyzed in the presence of Ca ions in water, oxalic acid generated by hydrolysis of polyoxalate reacts with Ca to produce calcium oxalate. Furthermore, with the passage of time, calcium oxalate crystals are precipitated, and the crystal particles close thecrack 3a. In short, the polyoxalate which is the flow path control agent 5 is not hydrolyzed but remains in the crack 3a as it is, and the excellent hydrolyzability of the polyoxalate is not utilized at all. It is.
即ち、地中には、石灰に代表されるように、Ｃａ化合物が多く分布しており、構成内に圧入された水には、Ｃａイオンが溶出している場合が多い。このように水中にＣａイオンが存在している状態でポリオキサレートが加水分解すると、ポリオキサレートの加水分解により生じたシュウ酸がＣａと反応してシュウ酸カルシウムが生成する。さらに、経時と共に、シュウ酸カルシウムの結晶が析出し、この結晶粒子により亀裂３ａが閉じられてしまうという不都合を生じる。要するに、流路制御剤５であるポリオキサレートが加水分解せずに、亀裂３ａ内にそのまま残存しているとの同じこととなってしまい、ポリオキサレートの優れた加水分解性が全く活かされないのである。 However, there is no problem when polyoxalate is hydrolyzed in pure water, but it is unexpected when hydrolyzed in water injected into a well formed in the ground. It turned out to be inconvenient.
That is, as represented by lime, a large amount of Ca compound is distributed in the ground, and in many cases, Ca ions are eluted in the water injected into the structure. Thus, when polyoxalate is hydrolyzed in the presence of Ca ions in water, oxalic acid generated by hydrolysis of polyoxalate reacts with Ca to produce calcium oxalate. Furthermore, with the passage of time, calcium oxalate crystals are precipitated, and the crystal particles close the
然るに、本発明では、ポリオキサレートが加水分解する水中に、キレート剤を共存させることにより、シュウ酸カルシウムの析出を有効に防止できる。その結果、ポリオキサレートの優れた加水分解性能を効果的に発揮させることができる。従って、特に水圧破砕法における流路制御剤５としてのポリオキサレートの使用が可能となる。
However, in the present invention, precipitation of calcium oxalate can be effectively prevented by allowing a chelating agent to coexist in water in which polyoxalate is hydrolyzed. As a result, the excellent hydrolysis performance of polyoxalate can be exhibited effectively. Therefore, it is possible to use polyoxalate as the flow path control agent 5 particularly in the hydraulic fracturing method.
また、本発明では、ポリオキサレートが加水分解する水中に、シュウ酸またはシュウ酸塩を捕捉するシュウ酸捕捉剤を共存させることによっても、シュウ酸カルシウムの析出を有効に防止できる。従って、キレート剤に代え、またはキレート剤とともにシュウ酸捕捉剤を使用することにより、ポリオキサレートの加水分解性能を効果的に発揮させることができる。
In the present invention, the precipitation of calcium oxalate can also be effectively prevented by allowing an oxalic acid scavenger that captures oxalic acid or oxalate to coexist in water in which polyoxalate is hydrolyzed. Therefore, by using the oxalic acid scavenger instead of the chelating agent or together with the chelating agent, the hydrolysis performance of the polyoxalate can be effectively exhibited.
＜ポリオキサレート＞
本発明において、加水分解性樹脂材料として使用されるポリオキサレートは、シュウ酸とジオールとからなるエステル単位を主構成単位として有するポリマーである。この主構成単位は、下記式（１）：
－ＣＯＣＯ－Ｏ－Ｒ１－Ｏ－ （１）
式中、Ｒ１は、ジオール残基である、
で表される。ジオール残基Ｒ１としては、メチレン、エチレン、プロピレン、ブチレン等のアルキレン基が代表的であるが、最も好適にはエチレン或いはブチレンである。このポリオキサレートは、例えばシュウ酸ジメチルとエチレングリコール、ブタンジオールとのエステル交換反応により得られる。
また、ポリオキサレートの優れた加水分解性が損なわれない限り、上記の主構成単位として、例えば下記式（２）：
－ＣＯ－Ｒ２－ＣＯ－（ＣＨ２）２－Ｏ－ （２）
式中、Ｒ２は、芳香族炭化水素環或いは脂肪族炭化水素環を含む２価
の環状基、例えば、ベンゼン環基、ナフタレン環基、シクロヘキサン環
基、特にｐ－フェニレン基である、またはメチレン、エチレン等のアル
キレン基である、
で表される共重合エステル単位を、５～５０モル％、特に５～３０モル％の割合で含んでいるポリオキサレート共重合体であってもよい。 <Polyoxalate>
In the present invention, the polyoxalate used as the hydrolyzable resin material is a polymer having an ester unit composed of oxalic acid and a diol as a main constituent unit. This main structural unit is represented by the following formula (1):
—COCO—O—R 1 —O— (1)
Where R 1 is a diol residue.
It is represented by The diol residue R 1 is typically an alkylene group such as methylene, ethylene, propylene, butylene, etc., and most preferably ethylene or butylene. This polyoxalate can be obtained, for example, by a transesterification reaction between dimethyl oxalate and ethylene glycol or butanediol.
In addition, as long as the excellent hydrolyzability of the polyoxalate is not impaired, as the main structural unit, for example, the following formula (2):
—CO—R 2 —CO— (CH 2 ) 2 —O— (2)
In the formula, R 2 is a divalent cyclic group containing an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring, for example, a benzene ring group, a naphthalene ring group, a cyclohexane ring group, particularly a p-phenylene group, or methylene An alkylene group such as ethylene,
A polyoxalate copolymer containing 5 to 50 mol%, particularly 5 to 30 mol% of a copolymer ester unit represented by
本発明において、加水分解性樹脂材料として使用されるポリオキサレートは、シュウ酸とジオールとからなるエステル単位を主構成単位として有するポリマーである。この主構成単位は、下記式（１）：
－ＣＯＣＯ－Ｏ－Ｒ１－Ｏ－ （１）
式中、Ｒ１は、ジオール残基である、
で表される。ジオール残基Ｒ１としては、メチレン、エチレン、プロピレン、ブチレン等のアルキレン基が代表的であるが、最も好適にはエチレン或いはブチレンである。このポリオキサレートは、例えばシュウ酸ジメチルとエチレングリコール、ブタンジオールとのエステル交換反応により得られる。
また、ポリオキサレートの優れた加水分解性が損なわれない限り、上記の主構成単位として、例えば下記式（２）：
－ＣＯ－Ｒ２－ＣＯ－（ＣＨ２）２－Ｏ－ （２）
式中、Ｒ２は、芳香族炭化水素環或いは脂肪族炭化水素環を含む２価
の環状基、例えば、ベンゼン環基、ナフタレン環基、シクロヘキサン環
基、特にｐ－フェニレン基である、またはメチレン、エチレン等のアル
キレン基である、
で表される共重合エステル単位を、５～５０モル％、特に５～３０モル％の割合で含んでいるポリオキサレート共重合体であってもよい。 <Polyoxalate>
In the present invention, the polyoxalate used as the hydrolyzable resin material is a polymer having an ester unit composed of oxalic acid and a diol as a main constituent unit. This main structural unit is represented by the following formula (1):
—COCO—O—R 1 —O— (1)
Where R 1 is a diol residue.
It is represented by The diol residue R 1 is typically an alkylene group such as methylene, ethylene, propylene, butylene, etc., and most preferably ethylene or butylene. This polyoxalate can be obtained, for example, by a transesterification reaction between dimethyl oxalate and ethylene glycol or butanediol.
In addition, as long as the excellent hydrolyzability of the polyoxalate is not impaired, as the main structural unit, for example, the following formula (2):
—CO—R 2 —CO— (CH 2 ) 2 —O— (2)
In the formula, R 2 is a divalent cyclic group containing an aromatic hydrocarbon ring or an aliphatic hydrocarbon ring, for example, a benzene ring group, a naphthalene ring group, a cyclohexane ring group, particularly a p-phenylene group, or methylene An alkylene group such as ethylene,
A polyoxalate copolymer containing 5 to 50 mol%, particularly 5 to 30 mol% of a copolymer ester unit represented by
また、適度な加水分解性と粉砕性を確保するために、このようなポリオキサレートの重量平均分子量Ｍｗは、５，０００～２００，０００、特に５，０００～１００，０００の範囲にあることが望ましい。
Further, in order to ensure appropriate hydrolyzability and grindability, the weight average molecular weight Mw of such polyoxalate is in the range of 5,000 to 200,000, particularly 5,000 to 100,000. Is desirable.
＜キレート剤＞
本発明において使用されるキレート剤は、金属イオンに配位してキレート化合物を形成する多座配位子であり、本発明では、特にＣａイオンの捕捉に使用する。 <Chelating agent>
The chelating agent used in the present invention is a multidentate ligand that coordinates to a metal ion to form a chelate compound. In the present invention, the chelating agent is particularly used for capturing Ca ions.
本発明において使用されるキレート剤は、金属イオンに配位してキレート化合物を形成する多座配位子であり、本発明では、特にＣａイオンの捕捉に使用する。 <Chelating agent>
The chelating agent used in the present invention is a multidentate ligand that coordinates to a metal ion to form a chelate compound. In the present invention, the chelating agent is particularly used for capturing Ca ions.
このようなキレート剤としては、Ｃａイオンと反応して水溶性のキレート化合物を生成するものであれば特に制限されないが、特に水溶性の結晶粉末或いは液状品が好適に使用される。樹脂もしくは繊維状のキレート剤も知られているが、これらは水中に残存して亀裂の閉塞を生じるおそれがあるため適当ではない。
Such a chelating agent is not particularly limited as long as it reacts with Ca ions to produce a water-soluble chelate compound, but water-soluble crystal powder or liquid product is particularly preferably used. Resins or fibrous chelating agents are also known, but these are not suitable because they can remain in water and cause clogging of cracks.
また、結晶粉末或いは液状品のキレート剤としては、重合リン酸塩系（無機系）やアミノカルボン酸系（有機系）及びホスホン酸系キレート剤、及びアスパラギン酸系キレート剤のものが知られている。原理的には何れのタイプのキレート化剤も使用することができるが、化学的に安定であり、環境に悪影響を与えないという点で、アミノカルボン酸系、ホスホン酸系及びアスパラギン酸系のキレート剤が好適に使用される。
このようなアミノカルボン酸系のキレート剤の例としては、エチレンジアミン四酢酸、１，３－プロパンジアミン四酢酸、ニトリロ三酢酸、ジカルボキシメチルグルタミン酸、２－カルボキシフェニルイミノ二酢酸、Ｓ，Ｓ－エチレンジアミンジコハク酸、メチルグリシン二酢酸、１，２－シクロヘキサンジアミン四酢酸、ヒドロキシエチルエチレンジアミン三酢酸（ＨＥＤＴＡ）、ジヒドロキシエチルエチレンジアミン四酢酸（ＤＨＥＤＤＡ）、ジエチレントリアミン五酢酸（ＤＴＰＡ）、トリエチレンテトラアミン六酢酸（ＴＴＨＡ）などを挙げることができる。またホスホン酸系キレート剤の例としては、アミノトリメチレンホスホン酸（ＮＴＭＰ）、ヒドロキシエタンジホスホン酸（ＨＥＤＰ）、ホスホノブタントリカルボン酸（ＰＢＴＣ）、エチレンジアミンテトラメチレンホスホン酸（ＥＤＴＭＰ）などを挙げることができる。また、アスパラギン酸系キレート剤としては、Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ）などを挙げることができる。
本発明においては、特に入手が容易であり、Ｃａイオン捕捉のためのｐＨ調整も容易なエチレンジアミン四酢酸（ＥＤＴＡ）が最も好適に使用される。 As chelating agents for crystal powder or liquid products, polymerized phosphate (inorganic), aminocarboxylic acid (organic), phosphonic acid chelating agents, and aspartic acid chelating agents are known. Yes. In principle, any type of chelating agent can be used, but aminocarboxylic, phosphonic and aspartic chelates in that they are chemically stable and do not adversely affect the environment. Agents are preferably used.
Examples of such aminocarboxylic acid-based chelating agents include ethylenediaminetetraacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, dicarboxymethylglutamic acid, 2-carboxyphenyliminodiacetic acid, S, S-ethylenediamine. Disuccinic acid, methylglycine diacetic acid, 1,2-cyclohexanediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid (HEDTA), dihydroxyethylethylenediaminetetraacetic acid (DHEDDA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraamine hexaacetic acid ( TTHA) and the like. Examples of phosphonic acid chelating agents include amino trimethylene phosphonic acid (NTMP), hydroxyethane diphosphonic acid (HEDP), phosphonobutane tricarboxylic acid (PBTC), and ethylenediaminetetramethylene phosphonic acid (EDTMP). Can do. Examples of the aspartic acid chelating agent include L-aspartic acid diacetic acid (ADSA).
In the present invention, ethylenediaminetetraacetic acid (EDTA), which is particularly easy to obtain and easily adjusts the pH for capturing Ca ions, is most preferably used.
このようなアミノカルボン酸系のキレート剤の例としては、エチレンジアミン四酢酸、１，３－プロパンジアミン四酢酸、ニトリロ三酢酸、ジカルボキシメチルグルタミン酸、２－カルボキシフェニルイミノ二酢酸、Ｓ，Ｓ－エチレンジアミンジコハク酸、メチルグリシン二酢酸、１，２－シクロヘキサンジアミン四酢酸、ヒドロキシエチルエチレンジアミン三酢酸（ＨＥＤＴＡ）、ジヒドロキシエチルエチレンジアミン四酢酸（ＤＨＥＤＤＡ）、ジエチレントリアミン五酢酸（ＤＴＰＡ）、トリエチレンテトラアミン六酢酸（ＴＴＨＡ）などを挙げることができる。またホスホン酸系キレート剤の例としては、アミノトリメチレンホスホン酸（ＮＴＭＰ）、ヒドロキシエタンジホスホン酸（ＨＥＤＰ）、ホスホノブタントリカルボン酸（ＰＢＴＣ）、エチレンジアミンテトラメチレンホスホン酸（ＥＤＴＭＰ）などを挙げることができる。また、アスパラギン酸系キレート剤としては、Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ）などを挙げることができる。
本発明においては、特に入手が容易であり、Ｃａイオン捕捉のためのｐＨ調整も容易なエチレンジアミン四酢酸（ＥＤＴＡ）が最も好適に使用される。 As chelating agents for crystal powder or liquid products, polymerized phosphate (inorganic), aminocarboxylic acid (organic), phosphonic acid chelating agents, and aspartic acid chelating agents are known. Yes. In principle, any type of chelating agent can be used, but aminocarboxylic, phosphonic and aspartic chelates in that they are chemically stable and do not adversely affect the environment. Agents are preferably used.
Examples of such aminocarboxylic acid-based chelating agents include ethylenediaminetetraacetic acid, 1,3-propanediaminetetraacetic acid, nitrilotriacetic acid, dicarboxymethylglutamic acid, 2-carboxyphenyliminodiacetic acid, S, S-ethylenediamine. Disuccinic acid, methylglycine diacetic acid, 1,2-cyclohexanediaminetetraacetic acid, hydroxyethylethylenediaminetriacetic acid (HEDTA), dihydroxyethylethylenediaminetetraacetic acid (DHEDDA), diethylenetriaminepentaacetic acid (DTPA), triethylenetetraamine hexaacetic acid ( TTHA) and the like. Examples of phosphonic acid chelating agents include amino trimethylene phosphonic acid (NTMP), hydroxyethane diphosphonic acid (HEDP), phosphonobutane tricarboxylic acid (PBTC), and ethylenediaminetetramethylene phosphonic acid (EDTMP). Can do. Examples of the aspartic acid chelating agent include L-aspartic acid diacetic acid (ADSA).
In the present invention, ethylenediaminetetraacetic acid (EDTA), which is particularly easy to obtain and easily adjusts the pH for capturing Ca ions, is most preferably used.
上記のキレート剤は、イオンの価数に関係なく、１：１で反応して金属イオンと結合して安定なキレート化合物を形成する。従って、このようなキレート剤は、Ｃａイオンを完全に捕捉するために、下記式；
Ｘ≧Ｙ
式中、Ｘは前記キレート剤のモル量であり、
Ｙは、水中に存在するＣａイオンのモル量である、
を満足する量で使用することが好適である。
また、坑井に圧入された水に溶出するＣａイオンの量は、通常、多くとも１０００ｐｐｍ程度であるため、この量を明安として、キレート剤を過剰に使用することが望ましい。さらに、キレート剤を過剰に使用することにより、他の多価金属を捕捉することもできる。これにより、他の多価金属の不溶性塩の生成も抑制することができ、不溶性化合物による亀裂の閉塞をより確実に防止することができる。 The above chelating agent reacts at 1: 1 regardless of the valence of the ion and binds to the metal ion to form a stable chelate compound. Therefore, such a chelating agent has the following formula in order to completely capture Ca ions:
X ≧ Y
Where X is the molar amount of the chelating agent,
Y is the molar amount of Ca ions present in the water,
It is preferable to use it in an amount satisfying.
In addition, since the amount of Ca ions eluted in the water injected into the well is usually about 1000 ppm at most, it is desirable to use this chelating agent in excess with this amount as clear. Furthermore, other polyvalent metals can be captured by using an excessive amount of a chelating agent. Thereby, the production | generation of the insoluble salt of another polyvalent metal can also be suppressed, and the blockage | closure of the crack by an insoluble compound can be prevented more reliably.
Ｘ≧Ｙ
式中、Ｘは前記キレート剤のモル量であり、
Ｙは、水中に存在するＣａイオンのモル量である、
を満足する量で使用することが好適である。
また、坑井に圧入された水に溶出するＣａイオンの量は、通常、多くとも１０００ｐｐｍ程度であるため、この量を明安として、キレート剤を過剰に使用することが望ましい。さらに、キレート剤を過剰に使用することにより、他の多価金属を捕捉することもできる。これにより、他の多価金属の不溶性塩の生成も抑制することができ、不溶性化合物による亀裂の閉塞をより確実に防止することができる。 The above chelating agent reacts at 1: 1 regardless of the valence of the ion and binds to the metal ion to form a stable chelate compound. Therefore, such a chelating agent has the following formula in order to completely capture Ca ions:
X ≧ Y
Where X is the molar amount of the chelating agent,
Y is the molar amount of Ca ions present in the water,
It is preferable to use it in an amount satisfying.
In addition, since the amount of Ca ions eluted in the water injected into the well is usually about 1000 ppm at most, it is desirable to use this chelating agent in excess with this amount as clear. Furthermore, other polyvalent metals can be captured by using an excessive amount of a chelating agent. Thereby, the production | generation of the insoluble salt of another polyvalent metal can also be suppressed, and the blockage | closure of the crack by an insoluble compound can be prevented more reliably.
＜シュウ酸捕捉剤＞
本発明において使用されるシュウ酸捕捉剤は、シュウ酸もしくはシュウ酸塩（特にシュウ酸カルシウム）と速やかに反応して水溶性シュウ酸誘導体化合物を形成する水溶性化合物である。 <Oxalic acid scavenger>
The oxalic acid scavenger used in the present invention is a water-soluble compound that reacts quickly with oxalic acid or oxalate (particularly calcium oxalate) to form a water-soluble oxalic acid derivative compound.
本発明において使用されるシュウ酸捕捉剤は、シュウ酸もしくはシュウ酸塩（特にシュウ酸カルシウム）と速やかに反応して水溶性シュウ酸誘導体化合物を形成する水溶性化合物である。 <Oxalic acid scavenger>
The oxalic acid scavenger used in the present invention is a water-soluble compound that reacts quickly with oxalic acid or oxalate (particularly calcium oxalate) to form a water-soluble oxalic acid derivative compound.
このようなシュウ酸捕捉剤としては、Ｃａに優先してシュウ酸と反応して水溶性塩を形成する金属化合物を使用することができる。かかる化合物の金属としては、特にＫ、Ｃａ、Ｎａ及びＭｇよりもイオン化傾向の低い金属を挙げることができる。
例えば、Ｋ、Ｎａ及びＭｇの化合物は、シュウ酸と反応して塩を形成したとしてもＣａとイオン交換してシュウ酸カルシウムを生成してしまい、また、生成したシュウ酸カルシウムとは反応しない。従って、シュウ酸捕捉剤としては適当ではない。 As such an oxalic acid scavenger, a metal compound that reacts with oxalic acid to form a water-soluble salt in preference to Ca can be used. Examples of the metal of such a compound include metals having a lower ionization tendency than K, Ca, Na and Mg.
For example, even if a compound of K, Na, and Mg reacts with oxalic acid to form a salt, it ion-exchanges with Ca to generate calcium oxalate, and does not react with the generated calcium oxalate. Therefore, it is not suitable as an oxalic acid scavenger.
例えば、Ｋ、Ｎａ及びＭｇの化合物は、シュウ酸と反応して塩を形成したとしてもＣａとイオン交換してシュウ酸カルシウムを生成してしまい、また、生成したシュウ酸カルシウムとは反応しない。従って、シュウ酸捕捉剤としては適当ではない。 As such an oxalic acid scavenger, a metal compound that reacts with oxalic acid to form a water-soluble salt in preference to Ca can be used. Examples of the metal of such a compound include metals having a lower ionization tendency than K, Ca, Na and Mg.
For example, even if a compound of K, Na, and Mg reacts with oxalic acid to form a salt, it ion-exchanges with Ca to generate calcium oxalate, and does not react with the generated calcium oxalate. Therefore, it is not suitable as an oxalic acid scavenger.
また、上記のようにイオン化傾向の低い金属としては、地中に残存することにより環境に悪影響を与えるものは避けることが望ましい。このような観点からＡｌが最も好適である。
In addition, as described above, it is desirable to avoid metals that have a low ionization tendency and that adversely affect the environment by remaining in the ground. From such a viewpoint, Al is most preferable.
さらに、シュウ酸捕捉剤として使用されるＡｌ化合物としては、各種有機酸のＡｌ塩、無機酸のＡｌ塩（例えば、硫酸アルミニウム、塩化アルミニウム、硝酸アルミニウム等）を挙げることができるが、無機酸のＡｌ塩は、場合によっては水中に存在しているＣａやＣａイオンと反応して水不溶性のＣａ塩を生成したり、或いは環境に望ましくない塩化物などを生成するおそれがある。従って、シュウ酸捕捉剤として好適なＡｌ化合物は、有機酸のＡｌ塩や無機酸のＡｌ塩、例えば乳酸アルミニウムや塩化アルミニウムが最も好適である。
Furthermore, examples of the Al compound used as the oxalic acid scavenger include Al salts of various organic acids and Al salts of inorganic acids (for example, aluminum sulfate, aluminum chloride, aluminum nitrate, etc.). In some cases, the Al salt may react with Ca or Ca ions present in water to produce a water-insoluble Ca salt, or may produce chlorides that are undesirable for the environment. Therefore, an Al compound suitable as an oxalic acid scavenger is most preferably an Al salt of an organic acid or an Al salt of an inorganic acid, such as aluminum lactate or aluminum chloride.
本発明において使用されるシュウ酸捕捉剤は、水中に存在しているＣａイオンと反応してシュウ酸カルシウムの生成を有効に抑制し得るように、ポリオキサレートが投入される水中に存在しているＣａイオン量に応じて適宜の量で使用される。一般的には、水中に存在するＣａイオンとシュウ酸捕捉剤中の金属Ｍ（例えばＡｌ）との合計量（Ｍ＋Ｃａ）当りのＣａ量が８０モル％以下、好ましくは５５モル％以下、最も好ましくは２５モル％以下となるように、シュウ酸捕捉剤を使用することが好適である。
The oxalic acid scavenger used in the present invention is present in the water into which polyoxalate is added so that it can effectively suppress the formation of calcium oxalate by reacting with Ca ions present in the water. It is used in an appropriate amount depending on the amount of Ca ions present. Generally, the amount of Ca per total amount (M + Ca) of Ca ions present in water and metal M (for example, Al) in the oxalic acid scavenger is 80 mol% or less, preferably 55 mol% or less, most preferably It is preferable to use an oxalic acid scavenger so that is 25 mol% or less.
＜ポリオキサレートの加水分解＞
上記のようにキレート剤を共存させてのポリオキサレートの加水分解は、例えば、水圧破砕により亀裂の生成が行われる地中温度で行われるが、特にポリオキサレートの低温での優れた加水分解性を活かすため、３０～７０℃、特に３０～５０℃の地中温度で行われることが好適である。即ち、このような地中温度の存在するシェールガス等の採取に本発明は好適に適用される。 <Hydrolysis of polyoxalate>
As described above, hydrolysis of polyoxalate in the presence of a chelating agent is performed at an underground temperature where cracks are generated by, for example, hydraulic fracturing, and particularly excellent hydrolysis of polyoxalate at low temperatures. In order to take advantage of the properties, it is preferable to carry out at an underground temperature of 30 to 70 ° C., particularly 30 to 50 ° C. That is, the present invention is preferably applied to sampling of shale gas having such underground temperature.
上記のようにキレート剤を共存させてのポリオキサレートの加水分解は、例えば、水圧破砕により亀裂の生成が行われる地中温度で行われるが、特にポリオキサレートの低温での優れた加水分解性を活かすため、３０～７０℃、特に３０～５０℃の地中温度で行われることが好適である。即ち、このような地中温度の存在するシェールガス等の採取に本発明は好適に適用される。 <Hydrolysis of polyoxalate>
As described above, hydrolysis of polyoxalate in the presence of a chelating agent is performed at an underground temperature where cracks are generated by, for example, hydraulic fracturing, and particularly excellent hydrolysis of polyoxalate at low temperatures. In order to take advantage of the properties, it is preferable to carry out at an underground temperature of 30 to 70 ° C., particularly 30 to 50 ° C. That is, the present invention is preferably applied to sampling of shale gas having such underground temperature.
また、ポリオキサレートとキレート剤とは、キレート剤の形態に応じて、ポリオキサレートのペレットとキレート剤とを地上で混合して坑井内に圧入することもできるし、ポリオキサレートとキレート剤との混合物を含む水溶液を地表で調製し、この水溶液を坑井内に圧入することもできる。
さらに、キレート剤が結晶粉末の形態の場合には、ポリオキサレートとキレート剤とを混合した流路制御剤を予め調製しておき、かかる流路制御剤を、メッシュ粒径（篩残粒径）が５０００μｍ以下の粒状物乃至粉末の形態で、坑井内の水中に圧入することもできる。また、キレート剤をｐＨや温度、水で溶解する材料でコーティングやカプセル化させ、圧入することもできる。このような流路制御剤では、水中に存在するＣａイオン量（或いは通常存在するＣａイオン量の上限値）よりも過剰にキレート剤を含有させておくことが必要である。 Moreover, according to the form of the chelating agent, the polyoxalate and the chelating agent can be mixed on the ground with the polyoxalate pellets and the chelating agent, and can be press-fitted into the well, or the polyoxalate and the chelating agent. It is also possible to prepare an aqueous solution containing the mixture with the surface and press-fit the aqueous solution into the well.
Further, when the chelating agent is in the form of crystal powder, a flow path control agent in which polyoxalate and chelating agent are mixed is prepared in advance, and the flow path control agent is added to the mesh particle size (residual screen particle size). ) Can be pressed into the water in the well in the form of a granular material or powder of 5000 μm or less. Further, the chelating agent can be coated or encapsulated with a material that dissolves in pH, temperature, or water, and can be press-fitted. In such a flow path control agent, it is necessary to contain a chelating agent in excess of the amount of Ca ions present in water (or the upper limit of the amount of Ca ions normally present).
さらに、キレート剤が結晶粉末の形態の場合には、ポリオキサレートとキレート剤とを混合した流路制御剤を予め調製しておき、かかる流路制御剤を、メッシュ粒径（篩残粒径）が５０００μｍ以下の粒状物乃至粉末の形態で、坑井内の水中に圧入することもできる。また、キレート剤をｐＨや温度、水で溶解する材料でコーティングやカプセル化させ、圧入することもできる。このような流路制御剤では、水中に存在するＣａイオン量（或いは通常存在するＣａイオン量の上限値）よりも過剰にキレート剤を含有させておくことが必要である。 Moreover, according to the form of the chelating agent, the polyoxalate and the chelating agent can be mixed on the ground with the polyoxalate pellets and the chelating agent, and can be press-fitted into the well, or the polyoxalate and the chelating agent. It is also possible to prepare an aqueous solution containing the mixture with the surface and press-fit the aqueous solution into the well.
Further, when the chelating agent is in the form of crystal powder, a flow path control agent in which polyoxalate and chelating agent are mixed is prepared in advance, and the flow path control agent is added to the mesh particle size (residual screen particle size). ) Can be pressed into the water in the well in the form of a granular material or powder of 5000 μm or less. Further, the chelating agent can be coated or encapsulated with a material that dissolves in pH, temperature, or water, and can be press-fitted. In such a flow path control agent, it is necessary to contain a chelating agent in excess of the amount of Ca ions present in water (or the upper limit of the amount of Ca ions normally present).
キレート剤によるＣａイオンの捕捉（キレート化）に際しては、キレート剤の種類に応じて適正ｐＨが存在するために、ポリオキサレート及びキレート剤が投入される水のｐＨを所定の範囲に調整することが必要である。例えば、ＥＤＴＡを用いる場合には、アルカリ等の添加によりｐＨが５以上に調整される。
When capturing Ca ions with a chelating agent (chelation), there is an appropriate pH depending on the type of chelating agent, so the pH of water into which the polyoxalate and chelating agent are added should be adjusted to a predetermined range. is required. For example, when EDTA is used, the pH is adjusted to 5 or more by adding an alkali or the like.
ポリオキサレート及びキレート剤が添加される坑井内の水中には、地中の圧力によって亀裂が崩壊しないように用いられるプロパント（砂など）のような亀裂支持材を供給することができる。また、加圧によって亀裂が速やかに生成するように、グアガムやキサトンなどを増粘剤として添加することもできる。さらに、地中温度（加水分解温度）が５０℃以下の場合には、加水分解を促進するための酵素を配合しておくことも可能である。
A crack support material such as proppant (sand etc.) used so that cracks do not collapse due to underground pressure can be supplied to the water in the well where the polyoxalate and the chelating agent are added. In addition, guar gum, xanthone, or the like can be added as a thickening agent so that cracks are rapidly generated by pressurization. Furthermore, when underground temperature (hydrolysis temperature) is 50 degrees C or less, it is also possible to mix | blend the enzyme for promoting a hydrolysis.
キレート剤とともに、シュウ酸イオンと反応するシュウ酸捕捉剤、シュウ酸カルシウムの凝集防止剤並びにシュウ酸カルシウムの析出抑制やシュウ酸カルシウム結晶の成長抑制効果のある、カルボキシル基を有する低分子量ポリマーやホスホン酸及び無機リン酸といったスケール防止剤を用いることもできる。
Low molecular weight polymers and phosphones having carboxyl groups that have chelating agents, oxalic acid scavengers that react with oxalate ions, calcium oxalate aggregation inhibitors, and calcium oxalate precipitation suppression and calcium oxalate crystal growth suppression effects Scale inhibitors such as acids and inorganic phosphoric acids can also be used.
一方、シュウ酸捕捉剤を用いてのポリオキサレートの加水分解は、例えば、水圧破砕により亀裂の生成が行われる地中温度で行われるが、特にポリオキサレートの低温での優れた加水分解性を活かすため、３０～７０℃、特に３０～５０℃の地中温度で行われることが好適である。即ち、このような地中温度の存在するシェールガス等の採取に本発明は好適に適用される。
On the other hand, hydrolysis of polyoxalate using an oxalic acid scavenger is carried out at an underground temperature where cracks are generated by, for example, hydraulic fracturing, and particularly excellent hydrolyzability of polyoxalate at low temperatures. In order to take advantage of the above, it is preferable to carry out at an underground temperature of 30 to 70 ° C, particularly 30 to 50 ° C. That is, the present invention is preferably applied to sampling of shale gas having such underground temperature.
ポリオキサレートとシュウ酸捕捉剤とは、ポリオキサレートのペレットとシュウ酸捕捉剤とを地上で混合して坑井内に圧入することもできるし、ポリオキサレートとシュウ酸捕捉剤との混合物を含む水溶液を地表で調製し、この水溶液を坑井内に圧入することもできる。
さらに、ポリオキサレートとシュウ酸捕捉剤とを混合した流路制御剤を予め調製しておき、かかる流路制御剤を、メッシュ粒径（篩残粒径）が５０００μｍ以下の粒状物乃至粉末の形態で、坑井内の水中に圧入することもできる。またシュウ酸補足剤をｐＨや温度、水で溶解する材料でコーティングやカプセル化させ、圧入することもできる。このような流路制御剤では、一般に、ポリオキサレート１００質量部当り、シュウ酸捕捉剤が１０質量部以上、特に１５～１００質量部程度含まれていることが好ましい。即ち、坑井内に存在するＣａイオンの量は、多くとも１０００ｐｐｍ程度であるから、このような量でシュウ酸捕捉剤が配合されていれば、坑井内の水中に圧入した時、シュウ酸捕捉剤のＣａに対する量が前述した範囲以上となり、常にシュウ酸カルシウムの生成を抑制し、シュウ酸カルシウムによる亀裂の閉塞を有効に回避することができる。 The polyoxalate and the oxalic acid scavenger can be mixed on the ground with the pellets of the polyoxalate and the oxalic acid scavenger and pressed into the well, or the mixture of the polyoxalate and the oxalic acid scavenger It is also possible to prepare an aqueous solution containing it on the surface and press-fit this aqueous solution into the well.
Further, a flow path control agent in which polyoxalate and an oxalic acid scavenger are mixed is prepared in advance, and the flow path control agent is made of a granular material or powder having a mesh particle size (residual screen particle size) of 5000 μm or less. It can also be press-fitted into the water in the well in the form. Alternatively, the oxalic acid scavenger may be coated or encapsulated with a material that dissolves in pH, temperature, or water, and then injected. In general, such a flow path control agent preferably contains 10 parts by mass or more, particularly about 15 to 100 parts by mass of the oxalic acid scavenger per 100 parts by mass of the polyoxalate. That is, since the amount of Ca ions present in the well is at most about 1000 ppm, when the oxalic acid scavenger is blended in such an amount, when the oxalic acid scavenger is injected into the water in the well, the oxalic acid scavenger The amount of Ca with respect to Ca is equal to or greater than the above-described range, so that the formation of calcium oxalate can be constantly suppressed and crack closure due to calcium oxalate can be effectively avoided.
さらに、ポリオキサレートとシュウ酸捕捉剤とを混合した流路制御剤を予め調製しておき、かかる流路制御剤を、メッシュ粒径（篩残粒径）が５０００μｍ以下の粒状物乃至粉末の形態で、坑井内の水中に圧入することもできる。またシュウ酸補足剤をｐＨや温度、水で溶解する材料でコーティングやカプセル化させ、圧入することもできる。このような流路制御剤では、一般に、ポリオキサレート１００質量部当り、シュウ酸捕捉剤が１０質量部以上、特に１５～１００質量部程度含まれていることが好ましい。即ち、坑井内に存在するＣａイオンの量は、多くとも１０００ｐｐｍ程度であるから、このような量でシュウ酸捕捉剤が配合されていれば、坑井内の水中に圧入した時、シュウ酸捕捉剤のＣａに対する量が前述した範囲以上となり、常にシュウ酸カルシウムの生成を抑制し、シュウ酸カルシウムによる亀裂の閉塞を有効に回避することができる。 The polyoxalate and the oxalic acid scavenger can be mixed on the ground with the pellets of the polyoxalate and the oxalic acid scavenger and pressed into the well, or the mixture of the polyoxalate and the oxalic acid scavenger It is also possible to prepare an aqueous solution containing it on the surface and press-fit this aqueous solution into the well.
Further, a flow path control agent in which polyoxalate and an oxalic acid scavenger are mixed is prepared in advance, and the flow path control agent is made of a granular material or powder having a mesh particle size (residual screen particle size) of 5000 μm or less. It can also be press-fitted into the water in the well in the form. Alternatively, the oxalic acid scavenger may be coated or encapsulated with a material that dissolves in pH, temperature, or water, and then injected. In general, such a flow path control agent preferably contains 10 parts by mass or more, particularly about 15 to 100 parts by mass of the oxalic acid scavenger per 100 parts by mass of the polyoxalate. That is, since the amount of Ca ions present in the well is at most about 1000 ppm, when the oxalic acid scavenger is blended in such an amount, when the oxalic acid scavenger is injected into the water in the well, the oxalic acid scavenger The amount of Ca with respect to Ca is equal to or greater than the above-described range, so that the formation of calcium oxalate can be constantly suppressed and crack closure due to calcium oxalate can be effectively avoided.
また、ポリオキサレート及びシュウ酸捕捉剤が添加される坑井内の水中には、地中の圧力によって亀裂が崩壊しないように用いられるプロパント（砂など）のような亀裂支持材を供給することができる。また、加圧によって亀裂が速やかに生成するように、グアガムやキサトンなどを増粘剤として添加することもできる。さらに、地中温度（加水分解温度）が５０℃以下の場合には、加水分解を促進するための酵素を配合しておくことも可能である。
In addition, a crack support material such as proppant (sand etc.) used to prevent cracks from collapsing due to underground pressure can be supplied to the well water to which polyoxalate and oxalic acid scavenger are added. it can. In addition, guar gum, xanthone, or the like can be added as a thickening agent so that cracks are rapidly generated by pressurization. Furthermore, when underground temperature (hydrolysis temperature) is 50 degrees C or less, it is also possible to mix | blend the enzyme for promoting a hydrolysis.
また、シュウ酸補足剤とともに、カルシウムイオンと反応するキレート剤、シュウ酸カルシウムの凝集防止剤並びにシュウ酸カルシウムの析出抑制やシュウ酸カルシウム結晶の成長抑制効果のある、カルボキシル基を有する低分子量ポリマーやホスホン酸及び無機リン酸といったスケール防止剤を用いることもできる。
In addition, a chelating agent that reacts with calcium ions, a calcium oxalate aggregation inhibitor, a calcium oxalate precipitation inhibitor, and a low molecular weight polymer having a carboxyl group that has a calcium oxalate crystal growth inhibitory effect. Scale inhibitors such as phosphonic acid and inorganic phosphoric acid can also be used.
上述した本発明のポリオキサレートの加水分解方法は、その優れた加水分解性能を十分に活かして、フラクチュアリング流体を加圧しての亀裂の生成を有効に行うことができる。また、水圧破砕を繰り返し行って複数個所に亀裂を生成する作業も有効に行うことができる。
The above-described method for hydrolyzing polyoxalate according to the present invention can make effective use of the excellent hydrolysis performance to effectively generate cracks by pressurizing the fracturing fluid. Moreover, the operation | work which repeats hydraulic crushing and produces | generates a crack in several places can also be performed effectively.
本発明を次の例で説明する。
尚、実験例で用いたポリオキサレートの合成及び各種測定は、以下の方法で行った。 The invention is illustrated by the following examples.
In addition, the synthesis | combination and various measurements of the polyoxalate used by the experiment example were performed with the following method.
尚、実験例で用いたポリオキサレートの合成及び各種測定は、以下の方法で行った。 The invention is illustrated by the following examples.
In addition, the synthesis | combination and various measurements of the polyoxalate used by the experiment example were performed with the following method.
＜ポリエチレンオキサレート（ＰＥＯｘ）の重合＞
マントルヒーター、液温の温度計、攪拌装置、窒素導入管、留出カラムを取り付けた１Ｌのセパラブルフラスコに、
シュウ酸ジメチル ２９５ｇ（２．５モル）
エチレングリコール １７１ｇ（２．７６モル）
１，４－ブタンジオール ２１．６ｇ（０．２４モル）
ジブチルスズオキシド ０．０６２ｇ
を入れ、窒素気流下でフラスコ内の液温を１１０℃に加温し、常圧重合を行った。
メタノールの留去の開始後１時間保温し反応させ、次いで１０℃／３０分の昇温速度で１８０℃まで昇温し常圧重合させた。その後、フラスコ内の液温を１９０℃、０．１ｋＰａ～０．８ｋＰａの減圧度で減圧重合させ、得られたポリマーを取り出した。
得られたＰＥＯｘの融点は、１６５℃、重量平均分子量Ｍｗは、１００，０００であった。 <Polymerization of polyethylene oxalate (PEOx)>
In a 1 L separable flask equipped with a mantle heater, a liquid temperature thermometer, a stirrer, a nitrogen inlet tube, and a distillation column,
Dimethyl oxalate 295 g (2.5 mol)
171 g (2.76 mol) of ethylene glycol
1,4-butanediol 21.6 g (0.24 mol)
Dibutyltin oxide 0.062g
Under a nitrogen stream, the liquid temperature in the flask was heated to 110 ° C., and normal pressure polymerization was performed.
After starting the distillation of methanol, the mixture was kept warm for 1 hour for reaction, and then heated to 180 ° C. at a rate of temperature increase of 10 ° C./30 minutes to carry out atmospheric pressure polymerization. Thereafter, the temperature of the liquid in the flask was polymerized under reduced pressure at 190 ° C. and a reduced pressure of 0.1 kPa to 0.8 kPa, and the resulting polymer was taken out.
The obtained PEOx had a melting point of 165 ° C. and a weight average molecular weight Mw of 100,000.
マントルヒーター、液温の温度計、攪拌装置、窒素導入管、留出カラムを取り付けた１Ｌのセパラブルフラスコに、
シュウ酸ジメチル ２９５ｇ（２．５モル）
エチレングリコール １７１ｇ（２．７６モル）
１，４－ブタンジオール ２１．６ｇ（０．２４モル）
ジブチルスズオキシド ０．０６２ｇ
を入れ、窒素気流下でフラスコ内の液温を１１０℃に加温し、常圧重合を行った。
メタノールの留去の開始後１時間保温し反応させ、次いで１０℃／３０分の昇温速度で１８０℃まで昇温し常圧重合させた。その後、フラスコ内の液温を１９０℃、０．１ｋＰａ～０．８ｋＰａの減圧度で減圧重合させ、得られたポリマーを取り出した。
得られたＰＥＯｘの融点は、１６５℃、重量平均分子量Ｍｗは、１００，０００であった。 <Polymerization of polyethylene oxalate (PEOx)>
In a 1 L separable flask equipped with a mantle heater, a liquid temperature thermometer, a stirrer, a nitrogen inlet tube, and a distillation column,
Dimethyl oxalate 295 g (2.5 mol)
171 g (2.76 mol) of ethylene glycol
1,4-butanediol 21.6 g (0.24 mol)
Dibutyltin oxide 0.062g
Under a nitrogen stream, the liquid temperature in the flask was heated to 110 ° C., and normal pressure polymerization was performed.
After starting the distillation of methanol, the mixture was kept warm for 1 hour for reaction, and then heated to 180 ° C. at a rate of temperature increase of 10 ° C./30 minutes to carry out atmospheric pressure polymerization. Thereafter, the temperature of the liquid in the flask was polymerized under reduced pressure at 190 ° C. and a reduced pressure of 0.1 kPa to 0.8 kPa, and the resulting polymer was taken out.
The obtained PEOx had a melting point of 165 ° C. and a weight average molecular weight Mw of 100,000.
＜ポリブチレンオキサレート（ＰＢＯｘ）の重合＞
マントルヒーター、液温の温度計、攪拌装置、窒素導入管、留出カラムを取り付けた１Ｌのセパラブルフラスコに、
シュウ酸ジメチル ３５４ｇ（３モル）
１，４－ブタンジオール ２７０ｇ（３モル）
ジブチルスズオキシド ０．０５ｇ
を入れ、窒素気流下でフラスコ内の液温を１００℃に加温し、常圧重合を行った。縮合水の留去の開始後、少しずつ液温を１８０℃まで昇温し常圧重合させた。最終的に１９６ｍｌの留去液を得た。
その後、フラスコ内の液温を、段階的に２００℃に昇温し、０．１ｋＰａ～０．８ｋＰａの減圧度で減圧重合を行った。得られたポリマーを取り出した。取り出したポリマーを液体窒素で冷却し、クラッシャーで破砕造粒した。
得られたＰＢＯｘの融点は、１０５℃、重量平均分子量は、８５，８００であった。 <Polybutylene oxalate (PBOx) polymerization>
In a 1 L separable flask equipped with a mantle heater, a liquid temperature thermometer, a stirrer, a nitrogen inlet tube, and a distillation column,
354 g (3 mol) of dimethyl oxalate
270 g (3 mol) of 1,4-butanediol
Dibutyltin oxide 0.05g
The temperature of the liquid in the flask was heated to 100 ° C. under a nitrogen stream, and normal pressure polymerization was performed. After the start of the distillation of the condensed water, the liquid temperature was gradually raised to 180 ° C. to carry out normal pressure polymerization. Finally, 196 ml of distillate was obtained.
Thereafter, the temperature of the liquid in the flask was gradually raised to 200 ° C., and vacuum polymerization was performed at a reduced pressure of 0.1 kPa to 0.8 kPa. The obtained polymer was taken out. The taken-out polymer was cooled with liquid nitrogen and crushed and granulated with a crusher.
The obtained PBOx had a melting point of 105 ° C. and a weight average molecular weight of 85,800.
マントルヒーター、液温の温度計、攪拌装置、窒素導入管、留出カラムを取り付けた１Ｌのセパラブルフラスコに、
シュウ酸ジメチル ３５４ｇ（３モル）
１，４－ブタンジオール ２７０ｇ（３モル）
ジブチルスズオキシド ０．０５ｇ
を入れ、窒素気流下でフラスコ内の液温を１００℃に加温し、常圧重合を行った。縮合水の留去の開始後、少しずつ液温を１８０℃まで昇温し常圧重合させた。最終的に１９６ｍｌの留去液を得た。
その後、フラスコ内の液温を、段階的に２００℃に昇温し、０．１ｋＰａ～０．８ｋＰａの減圧度で減圧重合を行った。得られたポリマーを取り出した。取り出したポリマーを液体窒素で冷却し、クラッシャーで破砕造粒した。
得られたＰＢＯｘの融点は、１０５℃、重量平均分子量は、８５，８００であった。 <Polybutylene oxalate (PBOx) polymerization>
In a 1 L separable flask equipped with a mantle heater, a liquid temperature thermometer, a stirrer, a nitrogen inlet tube, and a distillation column,
354 g (3 mol) of dimethyl oxalate
270 g (3 mol) of 1,4-butanediol
Dibutyltin oxide 0.05g
The temperature of the liquid in the flask was heated to 100 ° C. under a nitrogen stream, and normal pressure polymerization was performed. After the start of the distillation of the condensed water, the liquid temperature was gradually raised to 180 ° C. to carry out normal pressure polymerization. Finally, 196 ml of distillate was obtained.
Thereafter, the temperature of the liquid in the flask was gradually raised to 200 ° C., and vacuum polymerization was performed at a reduced pressure of 0.1 kPa to 0.8 kPa. The obtained polymer was taken out. The taken-out polymer was cooled with liquid nitrogen and crushed and granulated with a crusher.
The obtained PBOx had a melting point of 105 ° C. and a weight average molecular weight of 85,800.
＜ＰＥＯｘ及びＰＢＯｘの融点測定＞
装置：セイコーインスツルメント株式会社製ＤＳＣ６２２０（示差走査熱量測定）
試料調整：試料量５～１０ｍｇ
測定条件：窒素雰囲気下、１０℃／ｍｉｎの昇温速度で０℃～２５０℃の範囲で測定。
融点：ピークトップで求めた。 <Measurement of melting point of PEOx and PBOx>
Apparatus: DSC 6220 manufactured by Seiko Instruments Inc. (differential scanning calorimetry)
Sample preparation: Sample amount 5-10mg
Measurement conditions: Measured in the range of 0 ° C. to 250 ° C. at a rate of temperature increase of 10 ° C./min in a nitrogen atmosphere.
Melting point: determined at peak top.
装置：セイコーインスツルメント株式会社製ＤＳＣ６２２０（示差走査熱量測定）
試料調整：試料量５～１０ｍｇ
測定条件：窒素雰囲気下、１０℃／ｍｉｎの昇温速度で０℃～２５０℃の範囲で測定。
融点：ピークトップで求めた。 <Measurement of melting point of PEOx and PBOx>
Apparatus: DSC 6220 manufactured by Seiko Instruments Inc. (differential scanning calorimetry)
Sample preparation: Sample amount 5-10mg
Measurement conditions: Measured in the range of 0 ° C. to 250 ° C. at a rate of temperature increase of 10 ° C./min in a nitrogen atmosphere.
Melting point: determined at peak top.
＜ＰＥＯｘの分子量測定＞
装置：ゲル浸透クロマトグラフ（ＧＰＣ）
検出器：示差屈折率検出器ＲＩ
カラム：Ｓｈｏｄｅｘ ＨＦＩＰ－ＬＧ（１本）、ＨＦＩＰ－８０６Ｍ（２
本）（昭和電工）
溶媒：ヘキサフルオロイソプロパノール（５ｍＭ トリフルオロ酢酸ナトリ
ウム添加）
流速：０．５ｍＬ／ｍｉｎ
カラム温度：４０℃
試料調製：試料約１．５ｍｇに溶媒５ｍＬを加え、室温で緩やかに攪拌した
（試料濃度約０．０３％）。目視で溶解していることを確認した後、
０．４５μｍフィルターにて濾過した。スタンダードはポリメチルメ
タクリレートを用いた。 <Molecular weight measurement of PEOx>
Apparatus: Gel permeation chromatograph (GPC)
Detector: Differential refractive index detector RI
Column: Shodex HFIP-LG (1), HFIP-806M (2
Book) (Showa Denko)
Solvent: Hexafluoroisopropanol (5 mM sodium trifluoroacetate added)
Flow rate: 0.5 mL / min
Column temperature: 40 ° C
Sample preparation: 5 mL of a solvent was added to about 1.5 mg of a sample, and the mixture was gently stirred at room temperature (sample concentration: about 0.03%). After confirming that it is visually dissolved,
Filtration through a 0.45 μm filter. Polymethyl methacrylate was used as the standard.
装置：ゲル浸透クロマトグラフ（ＧＰＣ）
検出器：示差屈折率検出器ＲＩ
カラム：Ｓｈｏｄｅｘ ＨＦＩＰ－ＬＧ（１本）、ＨＦＩＰ－８０６Ｍ（２
本）（昭和電工）
溶媒：ヘキサフルオロイソプロパノール（５ｍＭ トリフルオロ酢酸ナトリ
ウム添加）
流速：０．５ｍＬ／ｍｉｎ
カラム温度：４０℃
試料調製：試料約１．５ｍｇに溶媒５ｍＬを加え、室温で緩やかに攪拌した
（試料濃度約０．０３％）。目視で溶解していることを確認した後、
０．４５μｍフィルターにて濾過した。スタンダードはポリメチルメ
タクリレートを用いた。 <Molecular weight measurement of PEOx>
Apparatus: Gel permeation chromatograph (GPC)
Detector: Differential refractive index detector RI
Column: Shodex HFIP-LG (1), HFIP-806M (2
Book) (Showa Denko)
Solvent: Hexafluoroisopropanol (5 mM sodium trifluoroacetate added)
Flow rate: 0.5 mL / min
Column temperature: 40 ° C
Sample preparation: 5 mL of a solvent was added to about 1.5 mg of a sample, and the mixture was gently stirred at room temperature (sample concentration: about 0.03%). After confirming that it is visually dissolved,
Filtration through a 0.45 μm filter. Polymethyl methacrylate was used as the standard.
＜ＰＢＯｘの分子量測定＞
装置：ゲル浸透クロマトグラフ（ＧＰＣ）
検出器：示差屈折率検出器ＲＩ
カラム：ＳｕｐｅｒＭｕｌｔｉｐｏｒｅ（２本）
溶媒：クロロホルム
流速：０．５ｍＬ／ｍｉｎ
カラム温度：４０℃
試料調製：試料約１０ｍｇに溶媒３ｍＬを加え、室温で放置した。目視で溶
解していることを確認した後、０．４５μｍフィルターにて濾過した
。スタンダードはポリスチレンを用いた。 <Measurement of molecular weight of PBOx>
Apparatus: Gel permeation chromatograph (GPC)
Detector: Differential refractive index detector RI
Column: SuperMultipore (2)
Solvent: Chloroform Flow rate: 0.5 mL / min
Column temperature: 40 ° C
Sample preparation: 3 mL of a solvent was added to about 10 mg of a sample and left at room temperature. After confirming that it was visually dissolved, the solution was filtered with a 0.45 μm filter. Polystyrene was used as the standard.
装置：ゲル浸透クロマトグラフ（ＧＰＣ）
検出器：示差屈折率検出器ＲＩ
カラム：ＳｕｐｅｒＭｕｌｔｉｐｏｒｅ（２本）
溶媒：クロロホルム
流速：０．５ｍＬ／ｍｉｎ
カラム温度：４０℃
試料調製：試料約１０ｍｇに溶媒３ｍＬを加え、室温で放置した。目視で溶
解していることを確認した後、０．４５μｍフィルターにて濾過した
。スタンダードはポリスチレンを用いた。 <Measurement of molecular weight of PBOx>
Apparatus: Gel permeation chromatograph (GPC)
Detector: Differential refractive index detector RI
Column: SuperMultipore (2)
Solvent: Chloroform Flow rate: 0.5 mL / min
Column temperature: 40 ° C
Sample preparation: 3 mL of a solvent was added to about 10 mg of a sample and left at room temperature. After confirming that it was visually dissolved, the solution was filtered with a 0.45 μm filter. Polystyrene was used as the standard.
＜ｐＨ測定＞
２５℃の条件下でｐＨ試験紙（ジョンソンユニバーサルｐＨ試験紙ロールタイプ：三商）により加水分解後の溶液のｐＨ測定を行った。 <PH measurement>
The pH of the solution after hydrolysis was measured with a pH test paper (Johnson Universal pH Test Paper Roll Type: Sansho) under the condition of 25 ° C.
２５℃の条件下でｐＨ試験紙（ジョンソンユニバーサルｐＨ試験紙ロールタイプ：三商）により加水分解後の溶液のｐＨ測定を行った。 <PH measurement>
The pH of the solution after hydrolysis was measured with a pH test paper (Johnson Universal pH Test Paper Roll Type: Sansho) under the condition of 25 ° C.
＜塩析の評価＞
加水分解後のサンプル瓶の残存物を、フィルター濾過により回収し、十分に乾燥させた後、残存物の重量を測定し、下記式により塩析量を求めた。
塩析量（％）＝１００×（残存物の重量）／（理論塩析量）
理論塩析量（ｇ）＝仕込みポリオキサレート（ｍｏｌ）
×シュウ酸カルシウム分子量（ｇ／ｍｏｌ） <Evaluation of salting out>
The residue in the sample bottle after hydrolysis was collected by filter filtration and sufficiently dried, then the weight of the residue was measured, and the amount of salting out was determined by the following formula.
Salting out amount (%) = 100 × (residual weight) / (theoretical salting out amount)
Theoretical salting-out amount (g) = charged polyoxalate (mol)
× Calcium oxalate molecular weight (g / mol)
加水分解後のサンプル瓶の残存物を、フィルター濾過により回収し、十分に乾燥させた後、残存物の重量を測定し、下記式により塩析量を求めた。
塩析量（％）＝１００×（残存物の重量）／（理論塩析量）
理論塩析量（ｇ）＝仕込みポリオキサレート（ｍｏｌ）
×シュウ酸カルシウム分子量（ｇ／ｍｏｌ） <Evaluation of salting out>
The residue in the sample bottle after hydrolysis was collected by filter filtration and sufficiently dried, then the weight of the residue was measured, and the amount of salting out was determined by the following formula.
Salting out amount (%) = 100 × (residual weight) / (theoretical salting out amount)
Theoretical salting-out amount (g) = charged polyoxalate (mol)
× Calcium oxalate molecular weight (g / mol)
＜実験例１＞
キレート剤として、ＥＤＴＡ（エチレンジアミン四酢酸：和光純薬工業社製）を用意した。
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
ＥＤＴＡ ０．０６ｇ（２．０５×１０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ａを調製した。
溶液Ａに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 1>
As a chelating agent, EDTA (ethylenediaminetetraacetic acid: manufactured by Wako Pure Chemical Industries, Ltd.) was prepared.
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
EDTA 0.06 g (2.05 × 10 −4 mol)
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution A.
0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added to solution A, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
キレート剤として、ＥＤＴＡ（エチレンジアミン四酢酸：和光純薬工業社製）を用意した。
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
ＥＤＴＡ ０．０６ｇ（２．０５×１０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ａを調製した。
溶液Ａに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 1>
As a chelating agent, EDTA (ethylenediaminetetraacetic acid: manufactured by Wako Pure Chemical Industries, Ltd.) was prepared.
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
EDTA 0.06 g (2.05 × 10 −4 mol)
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution A.
0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added to solution A, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
＜実験例２＞
上記の溶液Ａに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 2>
To the above solution A, 0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
上記の溶液Ａに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 2>
To the above solution A, 0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
＜実験例３＞
サンプル瓶に、
塩化カルシウム ０．０１５ｇ（１．３５×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ３ｍｌ
ＥＤＴＡ ０．０３ｇ（１．０３×１０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｂを調製した。
溶液Ｂに、ポリオキサレートして、ＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 3>
In the sample bottle,
0.015 g of calcium chloride (1.35 × 10 −4 mol)
0.1% sodium hydroxide aqueous solution 3ml
EDTA 0.03 g (1.03 × 10 −4 mol)
1 M Tris-HCl buffer (pH 9.0) 10 ml
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution B.
To solution B, polyoxalate, 0.04 g (3.45 × 10 −4 mol) of PEOx was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. Went.
The results are shown in Table 1.
サンプル瓶に、
塩化カルシウム ０．０１５ｇ（１．３５×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ３ｍｌ
ＥＤＴＡ ０．０３ｇ（１．０３×１０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｂを調製した。
溶液Ｂに、ポリオキサレートして、ＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 3>
In the sample bottle,
0.015 g of calcium chloride (1.35 × 10 −4 mol)
0.1% sodium hydroxide aqueous solution 3ml
EDTA 0.03 g (1.03 × 10 −4 mol)
1 M Tris-HCl buffer (pH 9.0) 10 ml
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution B.
To solution B, polyoxalate, 0.04 g (3.45 × 10 −4 mol) of PEOx was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. Went.
The results are shown in Table 1.
＜実験例４＞
溶液Ｂに、ポリオキサレートとして、ＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 4>
To the solution B, 0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added, hydrolyzed at 90 ° C. for 3 days, and pH and salting out were measured.
The results are shown in Table 1.
溶液Ｂに、ポリオキサレートとして、ＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 4>
To the solution B, 0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added, hydrolyzed at 90 ° C. for 3 days, and pH and salting out were measured.
The results are shown in Table 1.
＜実験例５＞
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
ＥＤＴＡ ０．０６ｇ（２．０５×１０－４ｍｏｌ）
３Ｍ酢酸緩衝液（ｐＨ５．０）１０ｍｌ
を入れ、塩化カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｃを調製した。
溶液Ｃに、ポリオキサレートとして、ＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 5>
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
EDTA 0.06 g (2.05 × 10 −4 mol)
10 ml of 3M acetate buffer (pH 5.0)
And stirred until calcium chloride and EDTA were completely dissolved to prepare solution C.
In solution C, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. went.
The results are shown in Table 1.
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
ＥＤＴＡ ０．０６ｇ（２．０５×１０－４ｍｏｌ）
３Ｍ酢酸緩衝液（ｐＨ５．０）１０ｍｌ
を入れ、塩化カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｃを調製した。
溶液Ｃに、ポリオキサレートとして、ＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 5>
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
EDTA 0.06 g (2.05 × 10 −4 mol)
10 ml of 3M acetate buffer (pH 5.0)
And stirred until calcium chloride and EDTA were completely dissolved to prepare solution C.
In solution C, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. went.
The results are shown in Table 1.
＜実験例６＞
溶液Ｃに、ポリオキサレートとして、ＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 6>
To the solution C, 0.04 g (2.78 × 10 −4 mol) of PBOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. went.
The results are shown in Table 1.
溶液Ｃに、ポリオキサレートとして、ＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 6>
To the solution C, 0.04 g (2.78 × 10 −4 mol) of PBOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. went.
The results are shown in Table 1.
＜実験例７＞
キレート剤として、Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ）を用意した。
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ） ０．０７ｇ（２．０５×１
０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｄを調製した。
溶液Ｄに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 7>
L-aspartate diacetate (ADSA) was prepared as a chelating agent.
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
L-aspartic acid diacetic acid (ADSA) 0.07 g (2.05 × 1
0-4 mol)
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution D.
To solution D, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
キレート剤として、Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ）を用意した。
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
Ｌ－アスパラギン酸二酢酸（ＡＤＳＡ） ０．０７ｇ（２．０５×１
０－４ｍｏｌ）
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムとＥＤＴＡが完全に溶解するまで撹拌し、溶液Ｄを調製した。
溶液Ｄに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental example 7>
L-aspartate diacetate (ADSA) was prepared as a chelating agent.
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
L-aspartic acid diacetic acid (ADSA) 0.07 g (2.05 × 1
0-4 mol)
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride and EDTA were completely dissolved to prepare solution D.
To solution D, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
＜実験例８＞
上記の溶液Ｄに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental Example 8>
0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added to the above solution D, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
上記の溶液Ｄに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Experimental Example 8>
0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added to the above solution D, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
＜比較例１＞
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムが完全に溶解するまで撹拌し、溶液Ｅを調製した。
溶液Ｅに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Comparative Example 1>
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride was completely dissolved to prepare solution E.
To solution E, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
サンプル瓶に、
塩化カルシウム ０．０２ｇ（１．８０×１０－４ｍｏｌ）
０．１％水酸化ナトリウム水溶液 ６ｍｌ
１Ｍトリス－ＨＣｌ緩衝液（ｐＨ９．０） １０ｍｌ（ｐＨ調整剤）
を入れ、塩酸カルシウムが完全に溶解するまで撹拌し、溶液Ｅを調製した。
溶液Ｅに、ポリオキサレートとしてＰＥＯｘを０．０４ｇ（３．４５×１０－４ｍｏｌ）投入し、電気オーブンにて９０℃の条件下で３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Comparative Example 1>
In the sample bottle,
Calcium chloride 0.02g (1.80 × 10 -4 mol)
0.1% aqueous sodium hydroxide solution 6ml
1M Tris-HCl buffer (pH 9.0) 10 ml (pH adjuster)
And stirred until calcium hydrochloride was completely dissolved to prepare solution E.
To solution E, 0.04 g (3.45 × 10 −4 mol) of PEOx as polyoxalate was added, and hydrolyzed in an electric oven at 90 ° C. for 3 days to measure pH and salting out. It was.
The results are shown in Table 1.
＜比較例２＞
上記の溶液Ｅに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Comparative example 2>
0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added to the above solution E, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
上記の溶液Ｅに、ポリオキサレートとしてＰＢＯｘを０．０４ｇ（２．７８×１０－４ｍｏｌ）投入し、９０℃３日間加水分解を行い、ｐＨと塩析測定を行った。
結果を表１に示す。 <Comparative example 2>
0.04 g (2.78 × 10 −4 mol) of PBOx as a polyoxalate was added to the above solution E, hydrolyzed at 90 ° C. for 3 days, and measured for pH and salting out.
The results are shown in Table 1.
＜実験例９～１４＞
以下の実験例は、Ｃａイオンの存在により、シュウ酸がＣａと反応してシュウ酸カルシウムが析出すること、及び乳酸アルミニウム（シュウ酸捕捉剤）の添加により、シュウ酸カルシウムの析出が抑制することを示すものである。 <Experimental Examples 9 to 14>
In the following experimental examples, the presence of Ca ions causes oxalic acid to react with Ca to precipitate calcium oxalate, and the addition of aluminum lactate (oxalic acid scavenger) suppresses the precipitation of calcium oxalate. Is shown.
以下の実験例は、Ｃａイオンの存在により、シュウ酸がＣａと反応してシュウ酸カルシウムが析出すること、及び乳酸アルミニウム（シュウ酸捕捉剤）の添加により、シュウ酸カルシウムの析出が抑制することを示すものである。 <Experimental Examples 9 to 14>
In the following experimental examples, the presence of Ca ions causes oxalic acid to react with Ca to precipitate calcium oxalate, and the addition of aluminum lactate (oxalic acid scavenger) suppresses the precipitation of calcium oxalate. Is shown.
以下のＡ液及びＢ液を用意した。
Ａ液：１％塩化カルシウム水溶液
Ｂ液：１％乳酸アルミニウム水溶液
Ｃ液：１％塩化アルミニウム水溶液
２０ｍｌのバイアル瓶に、上記のＡ液とＢ液とを表１に示す割合で加えた。そこに１％シュウ酸水溶液を３ｍｌ加え、７０℃オーブンで２時間加温した。上澄みを捨て、９０℃、５時間乾燥させ、析出物の量を測定した。
その結果を表２に示す。
また、シュウ酸カルシウムの析出量とＡｌに対するＣａ量を示すグラフである。 The following A liquid and B liquid were prepared.
Liquid A: 1% calcium chloride aqueous solution B liquid: 1% aluminum lactate aqueous solution C liquid: 1% aluminum chloride aqueous solution The above-mentioned liquid A and liquid B were added to a 20 ml vial at the ratio shown in Table 1. 3 ml of 1% oxalic acid aqueous solution was added thereto and heated in an oven at 70 ° C. for 2 hours. The supernatant was discarded and dried at 90 ° C. for 5 hours, and the amount of precipitate was measured.
The results are shown in Table 2.
Moreover, it is a graph which shows the amount of Ca with respect to the precipitation amount of calcium oxalate, and Al.
Ａ液：１％塩化カルシウム水溶液
Ｂ液：１％乳酸アルミニウム水溶液
Ｃ液：１％塩化アルミニウム水溶液
２０ｍｌのバイアル瓶に、上記のＡ液とＢ液とを表１に示す割合で加えた。そこに１％シュウ酸水溶液を３ｍｌ加え、７０℃オーブンで２時間加温した。上澄みを捨て、９０℃、５時間乾燥させ、析出物の量を測定した。
その結果を表２に示す。
また、シュウ酸カルシウムの析出量とＡｌに対するＣａ量を示すグラフである。 The following A liquid and B liquid were prepared.
Liquid A: 1% calcium chloride aqueous solution B liquid: 1% aluminum lactate aqueous solution C liquid: 1% aluminum chloride aqueous solution The above-mentioned liquid A and liquid B were added to a 20 ml vial at the ratio shown in Table 1. 3 ml of 1% oxalic acid aqueous solution was added thereto and heated in an oven at 70 ° C. for 2 hours. The supernatant was discarded and dried at 90 ° C. for 5 hours, and the amount of precipitate was measured.
The results are shown in Table 2.
Moreover, it is a graph which shows the amount of Ca with respect to the precipitation amount of calcium oxalate, and Al.
上記の実験結果から、シュウ酸は、Ｃａと反応してシュウ酸カルシウムを析出することが判り、乳酸アルミニウムの存在が、シュウ酸カルシウムの析出を抑制していることが理解される。
From the above experimental results, it is understood that oxalic acid reacts with Ca to precipitate calcium oxalate, and it is understood that the presence of aluminum lactate suppresses the precipitation of calcium oxalate.
＜実施例及び比較例＞
２０ｍｌのバイアル瓶にＰＥＯｘを３００ｍｇ加えた。そこに、表３に示すように実験例９～１４で用いたＡ液及びＢ液、またはＡ液及びＣ液を加え、９０℃のオーブンに４８時間静置した。上澄みを捨て、９０℃、５時間乾燥させ、沈殿物の重量を測定した。
また、下記式より残存率を算出した。
残存率＝（「沈殿物の重量」／３００）×１００（％）
結果を表３に示した。 <Examples and Comparative Examples>
300 mg of PEOx was added to a 20 ml vial. As shown in Table 3, solution A and solution B or solution A and solution C used in Experimental Examples 9 to 14 were added, and left in an oven at 90 ° C. for 48 hours. The supernatant was discarded, dried at 90 ° C. for 5 hours, and the weight of the precipitate was measured.
Moreover, the residual rate was computed from the following formula.
Residual rate = ("precipitate weight" / 300) x 100 (%)
The results are shown in Table 3.
２０ｍｌのバイアル瓶にＰＥＯｘを３００ｍｇ加えた。そこに、表３に示すように実験例９～１４で用いたＡ液及びＢ液、またはＡ液及びＣ液を加え、９０℃のオーブンに４８時間静置した。上澄みを捨て、９０℃、５時間乾燥させ、沈殿物の重量を測定した。
また、下記式より残存率を算出した。
残存率＝（「沈殿物の重量」／３００）×１００（％）
結果を表３に示した。 <Examples and Comparative Examples>
300 mg of PEOx was added to a 20 ml vial. As shown in Table 3, solution A and solution B or solution A and solution C used in Experimental Examples 9 to 14 were added, and left in an oven at 90 ° C. for 48 hours. The supernatant was discarded, dried at 90 ° C. for 5 hours, and the weight of the precipitate was measured.
Moreover, the residual rate was computed from the following formula.
Residual rate = ("precipitate weight" / 300) x 100 (%)
The results are shown in Table 3.
Claims (8)
- 水中でポリオキサレートを加水分解するポリオキサレート分解方法において、
前記水中に、Ｃａイオンを捕捉するためのキレート剤、またはシュウ酸もしくはシュウ酸塩と反応性を有するシュウ酸捕捉剤を、共存させてポリオキサレートの加水分解を促進させることを特徴とするポリオキサレート分解方法。 In a polyoxalate decomposition method in which polyoxalate is hydrolyzed in water,
A polychelate that promotes hydrolysis of polyoxalate by coexisting a chelating agent for capturing Ca ions or an oxalic acid scavenger reactive with oxalic acid or oxalate in the water. Oxalate decomposition method. - 前記水中にＣａイオンが存在しており、前記キレート剤を、下記式；
Ｘ≧Ｙ
式中、Ｘは前記キレート剤のモル量であり、
Ｙは、前記水中に存在するＣａイオンのモル量である、
で表される条件を満足する量で使用する請求項１に記載のポリオキサレート分解方法。 Ca ions are present in the water, and the chelating agent is represented by the following formula:
X ≧ Y
Where X is the molar amount of the chelating agent,
Y is the molar amount of Ca ions present in the water,
The method for decomposing a polyoxalate according to claim 1, wherein the polyoxalate is used in an amount satisfying the condition represented by: - 前記キレート剤がアミノカルボン酸系キレート剤、及びホスホン酸系キレート剤、及びアスパラギン酸系キレート剤の何れかである請求項２に記載のポリオキサレート分解方法。 3. The polyoxalate decomposition method according to claim 2, wherein the chelating agent is any one of an aminocarboxylic acid chelating agent, a phosphonic acid chelating agent, and an aspartic acid chelating agent.
- ｐＨが５以上に調整された水中に、前記ポリオキサレートおよびキレート剤を存在させる請求項１に記載のポリオキサレート分解方法。 The method for decomposing a polyoxalate according to claim 1, wherein the polyoxalate and the chelating agent are present in water whose pH is adjusted to 5 or more.
- 前記シュウ酸捕捉剤がＡｌ及びＡｌ化合物の何れかである、請求項１に記載のポリオキサレート分解方法。 The polyoxalate decomposition method according to claim 1, wherein the oxalic acid scavenger is any one of Al and an Al compound.
- 前記Ａｌ化合物が乳酸アルミニウムである請求項５に記載のポリオキサレート分解方法。 6. The polyoxalate decomposition method according to claim 5, wherein the Al compound is aluminum lactate.
- ポリオキサレートとシュウ酸捕捉剤とからなる流路制御剤。 A flow path control agent consisting of polyoxalate and oxalic acid scavenger.
- 前記シュウ酸捕捉剤がＡｌ化合物である請求項７に記載の流路制御剤。 The flow path control agent according to claim 7, wherein the oxalic acid scavenger is an Al compound.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016247649A JP2020026608A (en) | 2016-12-21 | 2016-12-21 | Method for decomposing poly-oxalate |
| JP2016-247649 | 2016-12-21 | ||
| JP2017-002771 | 2017-01-11 | ||
| JP2017002771A JP2020025897A (en) | 2017-01-11 | 2017-01-11 | Method of decomposing polyoxalate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2018116991A1 true WO2018116991A1 (en) | 2018-06-28 |
Family
ID=62627421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2017/045158 WO2018116991A1 (en) | 2016-12-21 | 2017-12-15 | Method for decomposing polyoxalate |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2018116991A1 (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5423702A (en) * | 1977-07-25 | 1979-02-22 | Mo Och Domsjoe Ab | Controlling method of deposits formation during cellulose pulp making or treating process |
| JPS60212589A (en) * | 1984-04-05 | 1985-10-24 | 日本重化学工業株式会社 | Prevention of scale in geothermal well |
| JPH01159388A (en) * | 1987-12-16 | 1989-06-22 | Mitsubishi Heavy Ind Ltd | Method for chemically cleaning slightly soluble scale |
| JP2008207065A (en) * | 2007-02-23 | 2008-09-11 | Petroleum Energy Center | Treatment method of organic wastewater |
| JP2010280866A (en) * | 2009-06-08 | 2010-12-16 | Niitaka:Kk | Pretreatment detergent composition and method for washing plastic container |
| JP2011212923A (en) * | 2010-03-31 | 2011-10-27 | Toyo Seikan Kaisha Ltd | Biodegradable laminate and biodegradable vessel using the same |
| JP2013166710A (en) * | 2012-02-14 | 2013-08-29 | Mikimoto Pharmaceut Co Ltd | Skin keratinization promoter and skin preparation for external use blended with the same |
| JP2013172690A (en) * | 2012-02-27 | 2013-09-05 | National Institute Of Advanced Industrial Science & Technology | Adhesion substrate for cell separation |
| JP2015209568A (en) * | 2014-04-25 | 2015-11-24 | パナソニックＩｐマネジメント株式会社 | Etching liquid and etching concentrated liquid for multilayer film containing molybdenum and copper and etching method |
| JP2016069744A (en) * | 2014-09-29 | 2016-05-09 | 株式会社日本触媒 | Pitch control agent for pulp containing (poly)oxyalkylene bond-containing copolymer |
| JP2016098503A (en) * | 2014-11-19 | 2016-05-30 | 東洋製罐グループホールディングス株式会社 | Underground resource mining method using hydraulic pressure fracturing method, and hydrolyzable antiblocking agent added to fluid used in hydraulic pressure fracturing |
-
2017
- 2017-12-15 WO PCT/JP2017/045158 patent/WO2018116991A1/en active Application Filing
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5423702A (en) * | 1977-07-25 | 1979-02-22 | Mo Och Domsjoe Ab | Controlling method of deposits formation during cellulose pulp making or treating process |
| JPS60212589A (en) * | 1984-04-05 | 1985-10-24 | 日本重化学工業株式会社 | Prevention of scale in geothermal well |
| JPH01159388A (en) * | 1987-12-16 | 1989-06-22 | Mitsubishi Heavy Ind Ltd | Method for chemically cleaning slightly soluble scale |
| JP2008207065A (en) * | 2007-02-23 | 2008-09-11 | Petroleum Energy Center | Treatment method of organic wastewater |
| JP2010280866A (en) * | 2009-06-08 | 2010-12-16 | Niitaka:Kk | Pretreatment detergent composition and method for washing plastic container |
| JP2011212923A (en) * | 2010-03-31 | 2011-10-27 | Toyo Seikan Kaisha Ltd | Biodegradable laminate and biodegradable vessel using the same |
| JP2013166710A (en) * | 2012-02-14 | 2013-08-29 | Mikimoto Pharmaceut Co Ltd | Skin keratinization promoter and skin preparation for external use blended with the same |
| JP2013172690A (en) * | 2012-02-27 | 2013-09-05 | National Institute Of Advanced Industrial Science & Technology | Adhesion substrate for cell separation |
| JP2015209568A (en) * | 2014-04-25 | 2015-11-24 | パナソニックＩｐマネジメント株式会社 | Etching liquid and etching concentrated liquid for multilayer film containing molybdenum and copper and etching method |
| JP2016069744A (en) * | 2014-09-29 | 2016-05-09 | 株式会社日本触媒 | Pitch control agent for pulp containing (poly)oxyalkylene bond-containing copolymer |
| JP2016098503A (en) * | 2014-11-19 | 2016-05-30 | 東洋製罐グループホールディングス株式会社 | Underground resource mining method using hydraulic pressure fracturing method, and hydrolyzable antiblocking agent added to fluid used in hydraulic pressure fracturing |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103261366B (en) | The ammonium salt of chelating agen and the purposes in oil gas field is applied thereof | |
| CN101133135B (en) | Use of water-soluble alkane sulfonic acids for increasing the permeability of underground petroliferous and/or gas-bearing carbonate rock formations and for dissolving carbonate contaminants and/or carbonate-containing impurity during petroleum production | |
| US8727002B2 (en) | Acidic treatment fluids containing non-polymeric silica scale control additives and methods related thereto | |
| DK2861692T3 (en) | PROCEDURE FOR THE PREPARATION OF OIL OR GAS FROM AN UNDERGROUND FORMATION USING A CHELATING AGENT | |
| CA2694151C (en) | Treatment fluids comprising clarified xanthan and associated methods | |
| AU2008212689B2 (en) | Methods for reducing the viscosity of treatment fluids comprising diutan | |
| CN104194758B (en) | Oil well neutral de-plugging agent composition and preparation method thereof | |
| CN103509534B (en) | Leak-stopping agent for petroleum drilling | |
| WO2012080297A1 (en) | Process to control iron in oil and gas applications using a chelating agent | |
| JPH11506488A (en) | Water-soluble polymer and composition thereof | |
| CA2864584A1 (en) | Hybrid aqueous-based suspensions for hydraulic fracturing operations | |
| CN104194757A (en) | Neutral blockage removing agent composition used for oilfield mechanical recovery well and preparation method thereof | |
| JP6451250B2 (en) | Hydrolytic fracturing method added to the fluid used for underground mining method and hydraulic fracturing using hydraulic fracturing method | |
| CN101896435A (en) | Methods of minimizing sulfate scale in oil field | |
| EP2870987B1 (en) | Alkali metal and/or alkali earth metal extraction method | |
| CN103131402A (en) | High temperature resistance solid free low damage well killing fluid and preparation method thereof | |
| CN104619773B (en) | Aqueous liquid dispersion and fracturing operation additive | |
| WO2018116991A1 (en) | Method for decomposing polyoxalate | |
| JP2020025897A (en) | Method of decomposing polyoxalate | |
| JP2020026608A (en) | Method for decomposing poly-oxalate | |
| US11248166B2 (en) | Composition to reduce friction reducer fouling in wellbores | |
| CN101374848A (en) | Process to prepare metal complex of N,N-bis(2-hydroxyethyl)glycine | |
| EP2920408A1 (en) | Kinetic hydrate inhibitors with pendent amino functionality | |
| Tungesvik | Synthesis and testing of new classes of scale inhibitors | |
| GB2613051A (en) | Filter cake removal compositions and methods of making and using same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 17883178 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 17883178 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: JP |