CA2408052A1 - Fracturing fluid - Google Patents
Fracturing fluid Download PDFInfo
- Publication number
- CA2408052A1 CA2408052A1 CA002408052A CA2408052A CA2408052A1 CA 2408052 A1 CA2408052 A1 CA 2408052A1 CA 002408052 A CA002408052 A CA 002408052A CA 2408052 A CA2408052 A CA 2408052A CA 2408052 A1 CA2408052 A1 CA 2408052A1
- Authority
- CA
- Canada
- Prior art keywords
- betaine
- water
- aqueous medium
- surfactant
- fracturing fluid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000012530 fluid Substances 0.000 title claims abstract description 83
- 229960003237 betaine Drugs 0.000 claims abstract description 141
- KWIUHFFTVRNATP-UHFFFAOYSA-N Betaine Natural products C[N+](C)(C)CC([O-])=O KWIUHFFTVRNATP-UHFFFAOYSA-N 0.000 claims abstract description 128
- KWIUHFFTVRNATP-UHFFFAOYSA-O N,N,N-trimethylglycinium Chemical compound C[N+](C)(C)CC(O)=O KWIUHFFTVRNATP-UHFFFAOYSA-O 0.000 claims abstract description 121
- 239000004094 surface-active agent Substances 0.000 claims abstract description 111
- 239000012736 aqueous medium Substances 0.000 claims abstract description 63
- 239000005486 organic electrolyte Substances 0.000 claims abstract description 43
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 37
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 27
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 75
- 239000000243 solution Substances 0.000 claims description 45
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 claims description 44
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 claims description 43
- 238000000034 method Methods 0.000 claims description 43
- 125000004079 stearyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims description 35
- WVDDGKGOMKODPV-UHFFFAOYSA-N Benzyl alcohol Chemical compound OCC1=CC=CC=C1 WVDDGKGOMKODPV-UHFFFAOYSA-N 0.000 claims description 30
- 125000004432 carbon atom Chemical group C* 0.000 claims description 22
- 159000000000 sodium salts Chemical class 0.000 claims description 22
- 239000000203 mixture Substances 0.000 claims description 20
- MWKFXSUHUHTGQN-UHFFFAOYSA-N decan-1-ol Chemical compound CCCCCCCCCCO MWKFXSUHUHTGQN-UHFFFAOYSA-N 0.000 claims description 16
- -1 dimethyl betaine Chemical compound 0.000 claims description 16
- 125000000217 alkyl group Chemical group 0.000 claims description 12
- 125000003118 aryl group Chemical group 0.000 claims description 12
- YRIUSKIDOIARQF-UHFFFAOYSA-N dodecyl benzenesulfonate Chemical compound CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 YRIUSKIDOIARQF-UHFFFAOYSA-N 0.000 claims description 12
- HLZKNKRTKFSKGZ-UHFFFAOYSA-N tetradecan-1-ol Chemical compound CCCCCCCCCCCCCCO HLZKNKRTKFSKGZ-UHFFFAOYSA-N 0.000 claims description 12
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 229920006395 saturated elastomer Polymers 0.000 claims description 11
- 239000011734 sodium Substances 0.000 claims description 11
- 229910052708 sodium Inorganic materials 0.000 claims description 11
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 10
- 125000002252 acyl group Chemical group 0.000 claims description 10
- 235000019445 benzyl alcohol Nutrition 0.000 claims description 10
- 239000004215 Carbon black (E152) Substances 0.000 claims description 9
- 229930195733 hydrocarbon Natural products 0.000 claims description 9
- 150000003839 salts Chemical class 0.000 claims description 9
- BXWNKGSJHAJOGX-UHFFFAOYSA-N hexadecan-1-ol Chemical compound CCCCCCCCCCCCCCCCO BXWNKGSJHAJOGX-UHFFFAOYSA-N 0.000 claims description 8
- QUCDWLYKDRVKMI-UHFFFAOYSA-M sodium;3,4-dimethylbenzenesulfonate Chemical compound [Na+].CC1=CC=C(S([O-])(=O)=O)C=C1C QUCDWLYKDRVKMI-UHFFFAOYSA-M 0.000 claims description 8
- POAOYUHQDCAZBD-UHFFFAOYSA-N 2-butoxyethanol Chemical compound CCCCOCCO POAOYUHQDCAZBD-UHFFFAOYSA-N 0.000 claims description 7
- ALKYHXVLJMQRLQ-UHFFFAOYSA-N 3-Hydroxy-2-naphthoate Chemical compound C1=CC=C2C=C(O)C(C(=O)O)=CC2=C1 ALKYHXVLJMQRLQ-UHFFFAOYSA-N 0.000 claims description 7
- 150000002430 hydrocarbons Chemical group 0.000 claims description 7
- 125000002091 cationic group Chemical group 0.000 claims description 6
- 230000002209 hydrophobic effect Effects 0.000 claims description 5
- 239000003760 tallow Substances 0.000 claims description 5
- 125000004417 unsaturated alkyl group Chemical group 0.000 claims description 5
- 125000002511 behenyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims description 4
- ABBQHOQBGMUPJH-UHFFFAOYSA-M Sodium salicylate Chemical compound [Na+].OC1=CC=CC=C1C([O-])=O ABBQHOQBGMUPJH-UHFFFAOYSA-M 0.000 claims description 3
- 239000002253 acid Substances 0.000 claims description 3
- JXLHNMVSKXFWAO-UHFFFAOYSA-N azane;7-fluoro-2,1,3-benzoxadiazole-4-sulfonic acid Chemical compound N.OS(=O)(=O)C1=CC=C(F)C2=NON=C12 JXLHNMVSKXFWAO-UHFFFAOYSA-N 0.000 claims description 3
- TYJOJLOWRIQYQM-UHFFFAOYSA-L disodium;phenyl phosphate Chemical compound [Na+].[Na+].[O-]P([O-])(=O)OC1=CC=CC=C1 TYJOJLOWRIQYQM-UHFFFAOYSA-L 0.000 claims description 3
- LPNBBFKOUUSUDB-UHFFFAOYSA-N p-toluic acid Chemical compound CC1=CC=C(C(O)=O)C=C1 LPNBBFKOUUSUDB-UHFFFAOYSA-N 0.000 claims description 3
- 125000000913 palmityl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 claims description 3
- 229960004025 sodium salicylate Drugs 0.000 claims description 3
- HFQQZARZPUDIFP-UHFFFAOYSA-M sodium;2-dodecylbenzenesulfonate Chemical compound [Na+].CCCCCCCCCCCCC1=CC=CC=C1S([O-])(=O)=O HFQQZARZPUDIFP-UHFFFAOYSA-M 0.000 claims description 3
- KVCGISUBCHHTDD-UHFFFAOYSA-M sodium;4-methylbenzenesulfonate Chemical compound [Na+].CC1=CC=C(S([O-])(=O)=O)C=C1 KVCGISUBCHHTDD-UHFFFAOYSA-M 0.000 claims description 3
- 125000001301 ethoxy group Chemical group [H]C([H])([H])C([H])([H])O* 0.000 claims description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 2
- 125000002572 propoxy group Chemical group [*]OC([H])([H])C(C([H])([H])[H])([H])[H] 0.000 claims description 2
- MZSDGDXXBZSFTG-UHFFFAOYSA-M sodium;benzenesulfonate Chemical compound [Na+].[O-]S(=O)(=O)C1=CC=CC=C1 MZSDGDXXBZSFTG-UHFFFAOYSA-M 0.000 claims description 2
- TYIOVYZMKITKRO-UHFFFAOYSA-N 2-[hexadecyl(dimethyl)azaniumyl]acetate Chemical group CCCCCCCCCCCCCCCC[N+](C)(C)CC([O-])=O TYIOVYZMKITKRO-UHFFFAOYSA-N 0.000 claims 17
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims 8
- 125000002947 alkylene group Chemical group 0.000 claims 4
- LQZZUXJYWNFBMV-UHFFFAOYSA-N dodecan-1-ol Chemical compound CCCCCCCCCCCCO LQZZUXJYWNFBMV-UHFFFAOYSA-N 0.000 claims 4
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims 4
- 239000010695 polyglycol Substances 0.000 claims 4
- 229920000151 polyglycol Polymers 0.000 claims 4
- 229910017053 inorganic salt Inorganic materials 0.000 claims 3
- KKMIHKCGXQMFEU-UHFFFAOYSA-N 2-[dimethyl(tetradecyl)azaniumyl]acetate Chemical compound CCCCCCCCCCCCCC[N+](C)(C)CC([O-])=O KKMIHKCGXQMFEU-UHFFFAOYSA-N 0.000 claims 2
- 125000002029 aromatic hydrocarbon group Chemical group 0.000 claims 2
- DQYBDCGIPTYXML-UHFFFAOYSA-N ethoxyethane;hydrate Chemical compound O.CCOCC DQYBDCGIPTYXML-UHFFFAOYSA-N 0.000 claims 2
- WVDDGKGOMKODPV-ZQBYOMGUSA-N phenyl(114C)methanol Chemical compound O[14CH2]C1=CC=CC=C1 WVDDGKGOMKODPV-ZQBYOMGUSA-N 0.000 claims 2
- GIPRGFRQMWSHAK-UHFFFAOYSA-M sodium;2-propan-2-ylbenzenesulfonate Chemical compound [Na+].CC(C)C1=CC=CC=C1S([O-])(=O)=O GIPRGFRQMWSHAK-UHFFFAOYSA-M 0.000 claims 2
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 claims 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 claims 1
- 229940090012 bentyl Drugs 0.000 claims 1
- MWOBKFYERIDQSZ-UHFFFAOYSA-N benzene;sodium Chemical compound [Na].C1=CC=CC=C1 MWOBKFYERIDQSZ-UHFFFAOYSA-N 0.000 claims 1
- 150000001732 carboxylic acid derivatives Chemical class 0.000 claims 1
- KWKXNDCHNDYVRT-UHFFFAOYSA-N dodecylbenzene Chemical compound CCCCCCCCCCCCC1=CC=CC=C1 KWKXNDCHNDYVRT-UHFFFAOYSA-N 0.000 claims 1
- ZCNGWQCRXUGQCW-UHFFFAOYSA-M sodium;3-hydroxynaphthalene-2-carboxylate Chemical compound [Na+].C1=CC=C2C=C(C([O-])=O)C(O)=CC2=C1 ZCNGWQCRXUGQCW-UHFFFAOYSA-M 0.000 claims 1
- 239000008096 xylene Substances 0.000 claims 1
- 238000005755 formation reaction Methods 0.000 abstract description 25
- 239000002280 amphoteric surfactant Substances 0.000 abstract 1
- 239000004615 ingredient Substances 0.000 abstract 1
- 239000000499 gel Substances 0.000 description 46
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 28
- 239000006260 foam Substances 0.000 description 19
- 239000001103 potassium chloride Substances 0.000 description 13
- 235000011164 potassium chloride Nutrition 0.000 description 13
- 238000005187 foaming Methods 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical group [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 239000003093 cationic surfactant Substances 0.000 description 6
- 125000001183 hydrocarbyl group Chemical group 0.000 description 6
- 239000000693 micelle Substances 0.000 description 6
- 239000003208 petroleum Substances 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 150000001412 amines Chemical class 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- 125000001931 aliphatic group Chemical group 0.000 description 4
- 230000035699 permeability Effects 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 125000001165 hydrophobic group Chemical group 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- 244000188595 Brassica sinapistrum Species 0.000 description 2
- 235000004977 Brassica sinapistrum Nutrition 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 230000004075 alteration Effects 0.000 description 2
- 239000011260 aqueous acid Substances 0.000 description 2
- 125000001797 benzyl group Chemical group [H]C1=C([H])C([H])=C(C([H])=C1[H])C([H])([H])* 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 239000003792 electrolyte Substances 0.000 description 2
- 231100000086 high toxicity Toxicity 0.000 description 2
- 230000000266 injurious effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 125000001421 myristyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 2
- 125000001117 oleyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])/C([H])=C([H])\C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])C([H])([H])[H] 0.000 description 2
- 150000003242 quaternary ammonium salts Chemical class 0.000 description 2
- 239000012266 salt solution Substances 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 230000000638 stimulation Effects 0.000 description 2
- 231100000331 toxic Toxicity 0.000 description 2
- 230000002588 toxic effect Effects 0.000 description 2
- 241001214257 Mene Species 0.000 description 1
- 241001474728 Satyrodes eurydice Species 0.000 description 1
- 150000008043 acidic salts Chemical class 0.000 description 1
- 239000003929 acidic solution Substances 0.000 description 1
- 239000013543 active substance Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000008052 alkyl sulfonates Chemical class 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- 125000000129 anionic group Chemical group 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 239000007798 antifreeze agent Substances 0.000 description 1
- 239000003899 bactericide agent Substances 0.000 description 1
- CMPOVQUVPYXEBN-UHFFFAOYSA-N bis(2-hydroxyethyl)-methylazanium;chloride Chemical compound Cl.OCCN(C)CCO CMPOVQUVPYXEBN-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- CSMFSDCPJHNZRY-UHFFFAOYSA-N decyl hydrogen sulfate Chemical compound CCCCCCCCCCOS(O)(=O)=O CSMFSDCPJHNZRY-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 150000002191 fatty alcohols Chemical class 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 239000008233 hard water Substances 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 239000000976 ink Substances 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- UFWIBTONFRDIAS-UHFFFAOYSA-N naphthalene-acid Natural products C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 1
- 230000007935 neutral effect Effects 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 125000006353 oxyethylene group Chemical group 0.000 description 1
- 235000011007 phosphoric acid Nutrition 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 150000007519 polyprotic acids Polymers 0.000 description 1
- BDERNNFJNOPAEC-UHFFFAOYSA-N propan-1-ol Chemical compound CCCO BDERNNFJNOPAEC-UHFFFAOYSA-N 0.000 description 1
- 125000001453 quaternary ammonium group Chemical group 0.000 description 1
- 239000011435 rock Substances 0.000 description 1
- 229960001860 salicylate Drugs 0.000 description 1
- YGSDEFSMJLZEOE-UHFFFAOYSA-M salicylate Chemical compound OC1=CC=CC=C1C([O-])=O YGSDEFSMJLZEOE-UHFFFAOYSA-M 0.000 description 1
- 229930195734 saturated hydrocarbon Natural products 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229940048842 sodium xylenesulfonate Drugs 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000008399 tap water Substances 0.000 description 1
- 235000020679 tap water Nutrition 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- 229930195735 unsaturated hydrocarbon Natural products 0.000 description 1
Classifications
-
- 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
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)
- Detergent Compositions (AREA)
Abstract
A subterranean fracturing fluid, which is relatively harmless to both the environment and subterranean formations includes an amphoteric surfactant, specifically a betaine surfactant and an organic electrolyte or an alcohol in an aqueous medium. Depending upon the proportions of the ingredients, the fluid can be foamed.
Description
FRACTURING FLUID
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to a fracturing fluid and to a method of fracturing a subterranean formation to increase the permeability of the formation.
More specifically, the invention provides a foamed, viscoelastic surfactant based fracturing fluid for fracturing a subterranean formation and transporting proppant into thus created fractures.
DISCUSSION OF THE PRIOR ART
Hydraulic fracturing has been used for many years to stimulate the production of petroleum from subterranean formations. In hydraulic fracturing, a fracturing fluid is injected through a wellbore into the formation at a pressure and flow rate sufficient to overcome the overburden stress and to initiate a fracture in the formation. Frequently, a proppant, whose function is to prevent the created fractures from closing back down upon itself when the pressure is released, is suspended in the fracturing fluid for transport into a fracture.
Proppants in use include, for example 20-40 mesh size sand and ceramics, but the most common proppant is sand. The proppant filled fractures provide permeable channels allowing petroleum to seep through the fractures into the wellbore from whence it is pumped to the surface. Accordingly, a desired fracturing fluid should have the following properties: (a) compatibility with the reservoir rock and reservoir fluids, (b) be sufficiently viscous and have a fluid structure capable of suspending proppants and transport them deep into the formation, (c) be stable enough to retain sufficient viscosity and fluid structure throughout proppant placement, (d) possess low fluid loss properties and low fluid flow friction pressures, (e) be easily removed from the formation with little residue, (f) be easily made under field conditions and (g) be' relatively inexpensive. Production of petroleum can be enhanced significantly by the use of specialized fracturing fluids, which exhibit high levels of rheological performance.
SUBSTITUTE SHEET (RULE 26) Fracturing fluids in common use include various aqueous gels and hydrocarbon gels.
The gels are formed by introducing cross-linkable polymers or surfactants into an aqueous or hydrocarbon fluid, followed by cross-linking of the polymer or surfactant molecules. The cross-linking give the fluid high viscoelastic properties that are necessary to transport and place proppants into the fractures.
Another widely used fracturing fluid is foramed, water-based fracturing fluid.
Such a fluid is described, for example, in U.S. Patent No. 3,980,136, issued to R.A.
Plummer et al on September 14, 1976. Briefly, the foamed fracturing process involves generation of foams with a desired quality which are pumped through a wellbore into a formation.
Typically, for aqueous systems, a polymer has to be hydrated in water at the surface before being pumped into the formation. The process of polymer hydration is time consuming and often requires bulky equipment at the wellsite. Another problem common to polymer-based fracturing fluids is that a significant amount of polymer residue is left in the formation resulting in negative impact on formation permeability.
. Viscoelastic surfactants have long been used for well stimulation. A
surfactant is a type of substance, which contains both hydrophobic and hydrophilic groups in the same molecule.
The hydrophobic group is usually one of a variety of alkyl groups and the hydrophilic group can be ionic, which may be positive (cationic), negative (anionic) or contain both positive and negative moieties (amphoteric), or nonionic - often consisting of a neutral polyoxyalkylene group. When dissolved in an aqueous medium, surfactants generally form various aggregates called micelles above a critical micelle concentration (cmc). At low concentration of surfactant, the micelles usually are small and spherical. Under certain conditions and surfactant concentrations, however, the spherical micelles grow in size andlor change their shape resulting in the formation of long flexible micelles. Above a certain concentration the long flexible micelles can become entangled and exhibit strong visoelastic behavior. Even though this feature has been observed in a number of systems containing nonionic and anionic surfactants, the effect is more pronounced in cationic surfactants, especially those containing an amine or quaternary ammonium group, in the presence of certain organic counterions such as, for example salicylate, benzonate and alkyl sulfonate. Viscoelastic surfactant fluids have been studied extensively in recent years and have found a wide variety of uses in many applications.
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
This invention relates to a fracturing fluid and to a method of fracturing a subterranean formation to increase the permeability of the formation.
More specifically, the invention provides a foamed, viscoelastic surfactant based fracturing fluid for fracturing a subterranean formation and transporting proppant into thus created fractures.
DISCUSSION OF THE PRIOR ART
Hydraulic fracturing has been used for many years to stimulate the production of petroleum from subterranean formations. In hydraulic fracturing, a fracturing fluid is injected through a wellbore into the formation at a pressure and flow rate sufficient to overcome the overburden stress and to initiate a fracture in the formation. Frequently, a proppant, whose function is to prevent the created fractures from closing back down upon itself when the pressure is released, is suspended in the fracturing fluid for transport into a fracture.
Proppants in use include, for example 20-40 mesh size sand and ceramics, but the most common proppant is sand. The proppant filled fractures provide permeable channels allowing petroleum to seep through the fractures into the wellbore from whence it is pumped to the surface. Accordingly, a desired fracturing fluid should have the following properties: (a) compatibility with the reservoir rock and reservoir fluids, (b) be sufficiently viscous and have a fluid structure capable of suspending proppants and transport them deep into the formation, (c) be stable enough to retain sufficient viscosity and fluid structure throughout proppant placement, (d) possess low fluid loss properties and low fluid flow friction pressures, (e) be easily removed from the formation with little residue, (f) be easily made under field conditions and (g) be' relatively inexpensive. Production of petroleum can be enhanced significantly by the use of specialized fracturing fluids, which exhibit high levels of rheological performance.
SUBSTITUTE SHEET (RULE 26) Fracturing fluids in common use include various aqueous gels and hydrocarbon gels.
The gels are formed by introducing cross-linkable polymers or surfactants into an aqueous or hydrocarbon fluid, followed by cross-linking of the polymer or surfactant molecules. The cross-linking give the fluid high viscoelastic properties that are necessary to transport and place proppants into the fractures.
Another widely used fracturing fluid is foramed, water-based fracturing fluid.
Such a fluid is described, for example, in U.S. Patent No. 3,980,136, issued to R.A.
Plummer et al on September 14, 1976. Briefly, the foamed fracturing process involves generation of foams with a desired quality which are pumped through a wellbore into a formation.
Typically, for aqueous systems, a polymer has to be hydrated in water at the surface before being pumped into the formation. The process of polymer hydration is time consuming and often requires bulky equipment at the wellsite. Another problem common to polymer-based fracturing fluids is that a significant amount of polymer residue is left in the formation resulting in negative impact on formation permeability.
. Viscoelastic surfactants have long been used for well stimulation. A
surfactant is a type of substance, which contains both hydrophobic and hydrophilic groups in the same molecule.
The hydrophobic group is usually one of a variety of alkyl groups and the hydrophilic group can be ionic, which may be positive (cationic), negative (anionic) or contain both positive and negative moieties (amphoteric), or nonionic - often consisting of a neutral polyoxyalkylene group. When dissolved in an aqueous medium, surfactants generally form various aggregates called micelles above a critical micelle concentration (cmc). At low concentration of surfactant, the micelles usually are small and spherical. Under certain conditions and surfactant concentrations, however, the spherical micelles grow in size andlor change their shape resulting in the formation of long flexible micelles. Above a certain concentration the long flexible micelles can become entangled and exhibit strong visoelastic behavior. Even though this feature has been observed in a number of systems containing nonionic and anionic surfactants, the effect is more pronounced in cationic surfactants, especially those containing an amine or quaternary ammonium group, in the presence of certain organic counterions such as, for example salicylate, benzonate and alkyl sulfonate. Viscoelastic surfactant fluids have been studied extensively in recent years and have found a wide variety of uses in many applications.
U.S. Patent No. 4,061,580, issued to R.W. Jahnke on December 6, 1977 discloses surfactant gelled fracturing and acidizing fluids suitable for well stimulation. The gelled fluids are prepared by adding certain amine salts to aqueous acid or salt solutions. The amine salts used as thickeners are prepared by merely mixing one equivalent of amine per equivalent of acid or, in the case of polybasic acids such as sulfuric and phosphoric acids, as little as one-half equivalent of amine per equivalent of acid may be used resulting in the formation of an acidic salt. The aqueous acid or salt solution can be gelled by the addition of the above-described salts. For example, 15% by weight of HCl can be gelled by the addition of a small amount, usual 3-10% by weight and typically about 5% by weight of an amine or amine salt as described above. For fracturing fluids, aqueous solutions containing some inorganic salts can be gelled by the addition of 3-10% by weight, preferably about 5% by weight, of an amine salt described above.
U.5. Patent No. 4,163,727, issued to C.G. Inks on August 7, 1979 discloses an acidizing-gel composition which consists essentially of, for example, about 15% by weight of HCI, about 20% by weight of a suitable nonionic gel-forming surfactant containing oxyethylene and oxypropylene units, a corrosion inhibitor to the extent needed, and the balance water.
U.5. Patents Nos. 5,551,516, issued to W.D. Norman et al on September 3, 1996 and 5,964,295, issued to J.E. Brown et al on October 12, 1999 disclose a fracturing fluid composition comprising a quaternary ammonium salt, erucyl bis (2-hydroxyethyl) methyl ammonium chloride, an organic salt such as sodium salicylate, inorganic salts such as ammonium chloride and potassium chloride and water. The patents state that the fluid has good viscoelastic properties and is easily formulated and handled. Furthermore, no or very little residue is left in a formation after the completion of the fracturing process. It is worth noting, however, that cationic surfactants such as amine and quaternary ammonium salts usually degrade very slowly, both aerobically and anaerobically, and moreover are highly toxic to marine organisms. The combination of low biodegradability and high toxicity is a fundamental criterion for a product injurious to the environment. In addition, cationic surfactants tend to rend the formation, especially sandstone formations, oil-wet adsorbing on the surface of clays and sands. The alteration of the formation wettability often reduces the relative permeability of petroleum aerobically and anaerobically, and moreover are highly toxic to marine organisms. The combination of low biodegradability and high toxicity is a fundameatal criterion for a product injurious to the enviTOtunent. 1u addition, cationic surfactants tend to tend the formation, especially sandstone formations, oil-wet adsorbing on the surface of clays and sands. The alteration of the formation wettability open redacts the relative permeability of petroleum leading to high water/petroleum ratio and low pzoduetion rates. The strong adsorption of cationic surfactant on the clay and sands may also adversely affect fluid viscosity_ GENERAL DESCRrPTION OF ~ nVVEN'><'IOhT
Thus, there is a genera! demand for surfactants, which are less harmful to both the environment and to subterranean formations, but which have the same exc~llant ability as above-mentioned cationic surfactants to form viseoelast~iic surfactant based fracturing fluids. An object of the present invention to meet this demstld.
Another object of the present invention is to overcome the disadvantages inherent to existing fracturing fluids by providing a fiacturing fluid having relatively goad foaming capability and foam stability in a wide range of temperatures.
According tv one aspect, the invention relates to a viseoelastic surfactant based fisctvai~qg fluid comprising an aqueous medium, at least one betaine surfactant having a saturated or unsaturated alkyl or acyl group containing 14-24 carbon atoms and a meatber selected from the group consisting of (a) at least one organic electrolyte having the general formula R,-A -wherein R1 is a hydrophobic aliphatic or aromatic, straight or branched, saturated or tuasaturated hydrocarbon gmup with 6-24 carbon atoms and A is a cationic, preferably monovalent group and (b) at least one alcohol having the general formula Ra-OH
v~rhcrein R2 is a hydrocarbon group with b-24 carbon atoms_ Nurrc~,oax~, 4 ::.>
.' Em~fa~3s '= AMENDED SHEET
According to a second aspect, the invention rdatcs to a method of fracttuing a Subterranean formation comprising the step of injecting a viscoelastic surfactant based fracturing fluid into the formation at a pressura sufficient to initiate fracturing, said fluid including an aqueous medium, at least one betsine surfactant having a saturated ~oT unsaturated alkyl or aryl group containing 1.4-24 carbon atoms and amernber selected from the group consisting of (a) at lease one organic electrolyte having the general formula Rl-A
wherein R~ is a hydrophobic aliphatic or aromatic, straight or branched, saturated or unsaturated hydrocarbon group with 6-24 carbon atoa~a and mvay also contain one or two hydrophilic moieties, and A is a cationic preferably monovalent group, and (b) at least one alcohol having the general formula Rx-OH
wherein Rz is a hydrocarbon with 6-24 carbon atoms.
DESCRIk?iON OF THE PREFERRED ElVf$OD
As described above, the basic courposition of the invention includes a viscoelastic surfactant, and the organic electrolyte or alcohol which arc all readily degradable. In additlan, since betaine surfactants have strong foaming capability, the present composition also gives an excellent foaming capability and foam stability within wide terapetature ranges, without employing additional foaming sutfactauts. The present .fluid may also contain a gas, for example, Nx or COZ, and thereby be in the form of foams or energized fluids. In other words, the present fluid may also be utilized as a foamed water-based fracturing fluid in the presence of gas.
The betaine surfactant has a saturated or unsaturated alkyl or acyl group with carbon atoms. When the surfactant is used with the organic electrolyte of the formula R,-A, tire generally molecular structure of the betaine surfactant is represented by the general formula CfI3 HursrExn~.oix~, 5 f~~fanss AMENDED SHEET
where R3 is an alkyl group or the group R'NHC3H6, in which R' is an acyl group. The groups R3 and R' can suitably be tetradecyl, hexadecyl, octadecyl, oleyl, rape seed alkyl and tallow alkyl or the corresponding acyl group.
As mentioned above the organic electrolyte has the general formula Rl-A
where Rl is a hydrocarbon group with 6-24 carbon atoms and A is a cationic, preferably monovalent group. The hydrophobic group Rl can be aliphatic or aromatic, straight or branched, saturated or unsaturated and may also contain one or two hydrophilic moieties The combination of the specific betaine surfactants and the organic electrolytes in an aqueous medium gives good viscoelastic properties within a wide temperature range. The fluids according to the invention can also tolerate hard water and a high concentration of salt. The carbon numbers of the hydrophobic groups, R3 R' and R, will determine the useful temperature range for a particular fluid so that high carbon numbers usually give products suitable for high temperatures.
When the betaine surfactant is used with an alcohol of the formula RZ-OH the general formula of the betaine surfactant is R3-N+-CHZCOO-Rs where R3 has the above-defined meaning, and R4 and RS are hydrocarbon aliphatic or unsaturated groups and may also containn one or two hydrophilic moieties, such as hydroxyl(-OH), or ethoxy or propoxy moieties. In the alcohol having the general structure RZ-OH
Rz is a hydrocarbon group with 6-24 carbon atoms. The hydrocarbon groups R2 can be aliphatic or aromatic, straight or branched, saturated or unsaturated. The combination of the specific betaine surfactants and alcohols in an aqueous medium also gives good viscoelastic properties within a given temperature range. The carbon numbers of the hydrocarbon groups R3 will betaine surfactants and alcobols is an aqueous medium also gives good viscoeiastic properties within a given tempi ~8w T~ ~°n T'"~'bers °f the hydrocarbon ~roups R3 will determine the useful tempcratme o for a particular fluid so that high carbon numbaas usually give products suitable far bigh tempcratuzes.
When the surfactant is used in combina'don with an or~c electrolyte, the preferred .. b~~~ extant is haxadecyl dimethyl betainc or oetadecYl dimethyl betaine.
Alternative - betaines may be employed either alone or in combination, includiutg rapeseed ~Yl ~~yl bctaine, oleyl, dimethyl betaine, tallow dimethyl betaine, myrsstyl . dimethyl betaine_ The preferred organic electmlyte is sodium salt of 3 hydroxy 2-naphthalene carboxYbc ~~' Alternatives include sodium xylcxse sulphonate, sodium 3-btydroxy-2-sodium ct>mene sulphonate, sodium salieyiate, sodium dodecyl benzene sulphonate, sodium toluene sulphonate, sodium toluate, sodium benzene sulphonate, sodium, hexadecylbenzenesulph°nate, sodium-phenyl phosphate, alkyl sulphates derived flora fatty alcohols or synthetic alcohols, and aikylareztesulphonates such as decylsulphate, dodecylsutphate, c~'o°bl~'1~~
tallowsulphate. It is worth noting that it is the anions instead of the canons, of the organic electrolyte which promote the fozmation of the viseoelastic surfactant gel when mined with the betaine surfactants in the aqueous medium.
When the surfactant is used with an alcohol, the prefemcd beta'n~e surfactant is octadeeyl dimethyl betaine. Alternative betaines roay be employed either alone or in combination, including erucyl diznettiyl betaine, docosyl dimethyl betaine, cctyl, dimcthyl betaine, tallow dimethyl betaanc, and myristyl dirnerhyl betanne. The preferred alcohol is benzyl alcohol Alternatives include decaaol, dod~ecanol and bexadecanol.
By "aqueous medium" is meant that at least 50% by weight, prefezably at least 90% by weight, of the water based liquid system consists of water. Within the teen are plain water and aqueous solutions of inorganic salts said aqueous alkaline or acidic solution.
Other exemplary aqueous liquids include mixtures ofwaier and watccc3aisetble liquids such as lower alkanols, c_g., methanol, ethanol or propanol, glycols and polyglycois. Also included arc emulsions of immiseible liquids in the aqueous liquids, aqueous slurries of solid particulates such as sands, ceramics, or other minerals and a number of conventional coxriponents such as clay stabilizers, antifreeze agents and bactericides. All of the additives, as well as the betainc s~ufa~tants; organic a~w~~~
Er~~fan~sz v-....-.::.::.........
===v. AMENDED SHEET ' -v The present invention is described below in greater detail by means of the following examples.
EXAMPLES
The foaming properties of the surfactant and organic electrolyte compositions according to the present invention were tested by a simple method involving the measuring of foam height and foam half life.
200 ml of gel sample were placed in a 1 litre blaring blender jar, and mixed at maximum blender speed for 30 seconds. The resulting foam was poured into a 1000 ml graduated cylinder, and a timer started. The foam height is the maximum volume occupied by the foam, and can be used to calculate foam quality. The half life is the time required for 100 ml of solution to accumulate in the bottom of the cylinder. For elevated temperatures, the sample, blender j an, and cylinder are heated to 10 C above the tested temperature for 15 minutes. 1n the following examples, the percentages are by weight and the viscosity is measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at room temperature.
Example 1 0.50 g of N-hexadecyl dimethyl betaine having the formula CH3(CHZ)ls N+(CH3)2CH2COO-(hereinafter referred to as C16 -betaine or C,6-BET) was dissolved in 0.4 ml isopropanol (IPA) and then mixed with 200 ml of tap water. The resulting solution was mixed with 0.27g of the sodium salt of dodecyl benzene sulphonate having the formula CH12H25~6H4S03~1a+
(hereinafter referred to as Na-LAS). A clear gel with high elasticity was formed. The gel was poured into a 1 litre Waning blender jar, and mixed at maximum blender speed for 30 seconds.
The resulting foam was tested in the manner described above. The test results are listed in Table I
Example 2 O.SOg of C,6 -BET was dissolved in 0.4 ml IPA, and then mixed with 200 ml of 7.0 wt%
of aqueous KCI solution. The resulting solution was mixed with 0,.098 g of the sodium salt ~of 3-hydroxy-2-naphthalenecarboxylic acid, CloH6(OH)COONa, (in the following called Na-BON).
A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 3 0.60g of C18 -betaine (Ci8-BET) was first dissolved in 1 ml isopropanol and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution. The resulting solution was mixed with 0.098 g of Na-BON. A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 4 0.50 g C18-BET was dissolved in 200 ml of 7.wt% of aqueous KCI solution at 40 C and then mixed with 0.7~ g of sodium xylene sulfonate (in the following called Na-XS). A clear gel with high elasticity was formed. The gel was cooled to room temperature. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 5 200 ml of gel with the composition specified in Example 4 was first subjected to saturation of COZ and then tested in the same manner as in Example 1. No significant changes in viscosity and foam properties were observed.
Example 6 200 ml of gel with the composition specified in Example 4 was first subjected to saturation of N2 and then tested in the same manner as in Example 1. No significant changes in viscosity and foam properties were observed.
Composition Viscosity of Foam height Foam Half Life base (approximategel (ml) (min) (cp) by weight) (1) 35 600 22 0.25 C16-BET
0.075 Na-LAS
0.2 IPA
balance water (2) 250 400 70 0.25 C16-BET
0.049 Na-BON
0.2 Il'A
7 KCl balance of water (3) 350 300 7 0.30 C1g-BET
0.049 Na-BON
0.5 IPA
balance of water (4) 285 620 45 0.40 C1$-BET
0.25 Na-XS
7 KCl balance of water From the results for the above examples, it is evident that C~6-betaine and C,g-betaine in combination with an organic salt electrolyte has good foaming capability and can be used for foam fracturing applications.
Example 7 1.0 g of CI8-BET was dissolved in 0.4 ml of IPA, and then mixed with 200 ml of 7.0%wt% of aqueous KCL solution. The resulting solution was mixed with 0.17 g of Na-LAS. A clear gel with high elasticity was formed. The viscosity of the gel was tested in the manner described above, and the results are listed in Table 2.
Example 8 0.75 g of C16-BET was dissolved in 0.4 ml of IPA, and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution. The resulting solution was mixed with 0.27 of Na-BON in NaOH solution. A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
Example 9 0.50 g of C1$-BET was first dissolved in 0.5 ml IPA and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution at 40 C. The resulting solution was mixed with 0.14 g of Na-BON
in NaOH solution. A clear gel with high elasticity was formed. The gel was cooled to room temperature and tested in the same manner as in Example 7. The results are shown in Table 2.
Example 10 1.0 g of C1g-BET was premixed with 0.8 ml of ethylene glycol monobutyl ether (EGMBE), 0.6 g of Na-XS and 0.4 ml of hot water. The resulting mixture was than mixed with 200 ml of 7.0 wt% of aqueous KCI solution at room temperature. A clear elastic gel was formed immediately. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
Example 11 0.75 g of C,g-BET was premixed with 0.8 ml of EGMBE, 0.6 g of Na-XS and 0.4 ml of hot water. The resulting mixture was then mixed with 200 ml of 7.0 wt% of aqueous KCl solution at room temperature. A clear elastic gel was formed immediately. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
TABLE
Compositions Viscosity of gels (approximate % by weight) (cp) (7) 240 0.5 C1g-BET
0.85 Na-LAS
0.201PA
7.0 KCL
balance of water (8) 1050 0.38 C16-BET
0.14 Na-BON
0.2 IPA
7.00 KCl balance of water (9) . 300 0.25 C18-BET
0.070 Na-BON
0.50 IPA
7.00 KCl balance of water (10) 855 0.50 C1g-BET
0.30 Na-XS
0.40 EGMBE
7.00 KCl balance of water (11) 570 0.38 C1$-BET
0.30 Na-XS
0.40 EGMBE
7.00 KCl balance of water Example 12 200 ml of gel with the composition specified in Table 2 for Example 10 was first subjected to saturation with COZ and then tested in the manner described above. No significant changes in viscosity and foam properties were observed.
Example 13 200 ml of gel with the composition specified in Table 2 for Example 10 was first subj ected to saturation with NZ and then tested in the manner described above. No significant changes in viscosity and foam properties were observed.
From the results of testing set out in Table 2 it is evident that combinations of a betaine surfactant and an organic electrolyte in the aqueous medium form clear gels with good viscoelastic properties. These gels can be used for hydraulic fracturing applications. For applications requiring higher viscosity, higher surfactant loading is generally required.
The foaming properties of the surfactant and organic alcohol compsoitions according to the present invention were tested by a simple method involving the measuring the viscosity of the gel.
Example 14 1.5 g active substance of octadecyl dimethyl betaine (in the following called betaine) was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution. The resulting surfactant solution was mixed with 0.8 g of hexadecanol at 55°C. A
clear gel with high elasticity was formed. the viscosity of the gel was measured using a Brookfield viscometer (Model LVT,Spindle 1 at 12 rpm) at 55°C. The results are listed in Table 3.
Example I S
1.5 g of C 18-betaine was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution.
The resulting surfactant solution was mixed with 0.6 g of tetradecanol at 40°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured suing a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 40°C. The results are listed in Table 3.
Example 16 1.5 g of C 18-betaine was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution.
The resulting surfactant solution was mixed with 0.2 g of decanol at 30°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 30°C. The results are shown in Table 3.
Example 17 1.0 g of C18-betaine was first dissolved in 200 ml of 5 wt% KC1 aqueous solution.
The resulting surfactant solution was mixed with 0.5 g of benzyl alcohol at 22°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 22°C. The results are shown in Table 3.
Example 18 1.5 of C16-betaine was first dissolved in 200 ml of 5 wt% KC1 aqueous solution. The resulting surfactant solution was mixed with 0.6 g of benzyl alcohol at 22°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Speindle 1 at 12 rpm) at 22°C. The results are shown in Table 3.
Table 3 Compositions Viscosity of gels 1. C18-Betaine 0.78% 340 cp Hexadecanol 0.4%
KCl 5.0%
2. C18-Betaine 0.75% 470 cp Tetradecanol 0.3 KCl S.0%
3. C18-Betaine 0.75% 750 cp Decanol 0.1 KCl 5.0%
4. C18-Betaine 0.5% 660 cp Benzyl alcohol0.25%
KCl 5.0%
U.5. Patent No. 4,163,727, issued to C.G. Inks on August 7, 1979 discloses an acidizing-gel composition which consists essentially of, for example, about 15% by weight of HCI, about 20% by weight of a suitable nonionic gel-forming surfactant containing oxyethylene and oxypropylene units, a corrosion inhibitor to the extent needed, and the balance water.
U.5. Patents Nos. 5,551,516, issued to W.D. Norman et al on September 3, 1996 and 5,964,295, issued to J.E. Brown et al on October 12, 1999 disclose a fracturing fluid composition comprising a quaternary ammonium salt, erucyl bis (2-hydroxyethyl) methyl ammonium chloride, an organic salt such as sodium salicylate, inorganic salts such as ammonium chloride and potassium chloride and water. The patents state that the fluid has good viscoelastic properties and is easily formulated and handled. Furthermore, no or very little residue is left in a formation after the completion of the fracturing process. It is worth noting, however, that cationic surfactants such as amine and quaternary ammonium salts usually degrade very slowly, both aerobically and anaerobically, and moreover are highly toxic to marine organisms. The combination of low biodegradability and high toxicity is a fundamental criterion for a product injurious to the environment. In addition, cationic surfactants tend to rend the formation, especially sandstone formations, oil-wet adsorbing on the surface of clays and sands. The alteration of the formation wettability often reduces the relative permeability of petroleum aerobically and anaerobically, and moreover are highly toxic to marine organisms. The combination of low biodegradability and high toxicity is a fundameatal criterion for a product injurious to the enviTOtunent. 1u addition, cationic surfactants tend to tend the formation, especially sandstone formations, oil-wet adsorbing on the surface of clays and sands. The alteration of the formation wettability open redacts the relative permeability of petroleum leading to high water/petroleum ratio and low pzoduetion rates. The strong adsorption of cationic surfactant on the clay and sands may also adversely affect fluid viscosity_ GENERAL DESCRrPTION OF ~ nVVEN'><'IOhT
Thus, there is a genera! demand for surfactants, which are less harmful to both the environment and to subterranean formations, but which have the same exc~llant ability as above-mentioned cationic surfactants to form viseoelast~iic surfactant based fracturing fluids. An object of the present invention to meet this demstld.
Another object of the present invention is to overcome the disadvantages inherent to existing fracturing fluids by providing a fiacturing fluid having relatively goad foaming capability and foam stability in a wide range of temperatures.
According tv one aspect, the invention relates to a viseoelastic surfactant based fisctvai~qg fluid comprising an aqueous medium, at least one betaine surfactant having a saturated or unsaturated alkyl or acyl group containing 14-24 carbon atoms and a meatber selected from the group consisting of (a) at least one organic electrolyte having the general formula R,-A -wherein R1 is a hydrophobic aliphatic or aromatic, straight or branched, saturated or tuasaturated hydrocarbon gmup with 6-24 carbon atoms and A is a cationic, preferably monovalent group and (b) at least one alcohol having the general formula Ra-OH
v~rhcrein R2 is a hydrocarbon group with b-24 carbon atoms_ Nurrc~,oax~, 4 ::.>
.' Em~fa~3s '= AMENDED SHEET
According to a second aspect, the invention rdatcs to a method of fracttuing a Subterranean formation comprising the step of injecting a viscoelastic surfactant based fracturing fluid into the formation at a pressura sufficient to initiate fracturing, said fluid including an aqueous medium, at least one betsine surfactant having a saturated ~oT unsaturated alkyl or aryl group containing 1.4-24 carbon atoms and amernber selected from the group consisting of (a) at lease one organic electrolyte having the general formula Rl-A
wherein R~ is a hydrophobic aliphatic or aromatic, straight or branched, saturated or unsaturated hydrocarbon group with 6-24 carbon atoa~a and mvay also contain one or two hydrophilic moieties, and A is a cationic preferably monovalent group, and (b) at least one alcohol having the general formula Rx-OH
wherein Rz is a hydrocarbon with 6-24 carbon atoms.
DESCRIk?iON OF THE PREFERRED ElVf$OD
As described above, the basic courposition of the invention includes a viscoelastic surfactant, and the organic electrolyte or alcohol which arc all readily degradable. In additlan, since betaine surfactants have strong foaming capability, the present composition also gives an excellent foaming capability and foam stability within wide terapetature ranges, without employing additional foaming sutfactauts. The present .fluid may also contain a gas, for example, Nx or COZ, and thereby be in the form of foams or energized fluids. In other words, the present fluid may also be utilized as a foamed water-based fracturing fluid in the presence of gas.
The betaine surfactant has a saturated or unsaturated alkyl or acyl group with carbon atoms. When the surfactant is used with the organic electrolyte of the formula R,-A, tire generally molecular structure of the betaine surfactant is represented by the general formula CfI3 HursrExn~.oix~, 5 f~~fanss AMENDED SHEET
where R3 is an alkyl group or the group R'NHC3H6, in which R' is an acyl group. The groups R3 and R' can suitably be tetradecyl, hexadecyl, octadecyl, oleyl, rape seed alkyl and tallow alkyl or the corresponding acyl group.
As mentioned above the organic electrolyte has the general formula Rl-A
where Rl is a hydrocarbon group with 6-24 carbon atoms and A is a cationic, preferably monovalent group. The hydrophobic group Rl can be aliphatic or aromatic, straight or branched, saturated or unsaturated and may also contain one or two hydrophilic moieties The combination of the specific betaine surfactants and the organic electrolytes in an aqueous medium gives good viscoelastic properties within a wide temperature range. The fluids according to the invention can also tolerate hard water and a high concentration of salt. The carbon numbers of the hydrophobic groups, R3 R' and R, will determine the useful temperature range for a particular fluid so that high carbon numbers usually give products suitable for high temperatures.
When the betaine surfactant is used with an alcohol of the formula RZ-OH the general formula of the betaine surfactant is R3-N+-CHZCOO-Rs where R3 has the above-defined meaning, and R4 and RS are hydrocarbon aliphatic or unsaturated groups and may also containn one or two hydrophilic moieties, such as hydroxyl(-OH), or ethoxy or propoxy moieties. In the alcohol having the general structure RZ-OH
Rz is a hydrocarbon group with 6-24 carbon atoms. The hydrocarbon groups R2 can be aliphatic or aromatic, straight or branched, saturated or unsaturated. The combination of the specific betaine surfactants and alcohols in an aqueous medium also gives good viscoelastic properties within a given temperature range. The carbon numbers of the hydrocarbon groups R3 will betaine surfactants and alcobols is an aqueous medium also gives good viscoeiastic properties within a given tempi ~8w T~ ~°n T'"~'bers °f the hydrocarbon ~roups R3 will determine the useful tempcratme o for a particular fluid so that high carbon numbaas usually give products suitable far bigh tempcratuzes.
When the surfactant is used in combina'don with an or~c electrolyte, the preferred .. b~~~ extant is haxadecyl dimethyl betainc or oetadecYl dimethyl betaine.
Alternative - betaines may be employed either alone or in combination, includiutg rapeseed ~Yl ~~yl bctaine, oleyl, dimethyl betaine, tallow dimethyl betaine, myrsstyl . dimethyl betaine_ The preferred organic electmlyte is sodium salt of 3 hydroxy 2-naphthalene carboxYbc ~~' Alternatives include sodium xylcxse sulphonate, sodium 3-btydroxy-2-sodium ct>mene sulphonate, sodium salieyiate, sodium dodecyl benzene sulphonate, sodium toluene sulphonate, sodium toluate, sodium benzene sulphonate, sodium, hexadecylbenzenesulph°nate, sodium-phenyl phosphate, alkyl sulphates derived flora fatty alcohols or synthetic alcohols, and aikylareztesulphonates such as decylsulphate, dodecylsutphate, c~'o°bl~'1~~
tallowsulphate. It is worth noting that it is the anions instead of the canons, of the organic electrolyte which promote the fozmation of the viseoelastic surfactant gel when mined with the betaine surfactants in the aqueous medium.
When the surfactant is used with an alcohol, the prefemcd beta'n~e surfactant is octadeeyl dimethyl betaine. Alternative betaines roay be employed either alone or in combination, including erucyl diznettiyl betaine, docosyl dimethyl betaine, cctyl, dimcthyl betaine, tallow dimethyl betaanc, and myristyl dirnerhyl betanne. The preferred alcohol is benzyl alcohol Alternatives include decaaol, dod~ecanol and bexadecanol.
By "aqueous medium" is meant that at least 50% by weight, prefezably at least 90% by weight, of the water based liquid system consists of water. Within the teen are plain water and aqueous solutions of inorganic salts said aqueous alkaline or acidic solution.
Other exemplary aqueous liquids include mixtures ofwaier and watccc3aisetble liquids such as lower alkanols, c_g., methanol, ethanol or propanol, glycols and polyglycois. Also included arc emulsions of immiseible liquids in the aqueous liquids, aqueous slurries of solid particulates such as sands, ceramics, or other minerals and a number of conventional coxriponents such as clay stabilizers, antifreeze agents and bactericides. All of the additives, as well as the betainc s~ufa~tants; organic a~w~~~
Er~~fan~sz v-....-.::.::.........
===v. AMENDED SHEET ' -v The present invention is described below in greater detail by means of the following examples.
EXAMPLES
The foaming properties of the surfactant and organic electrolyte compositions according to the present invention were tested by a simple method involving the measuring of foam height and foam half life.
200 ml of gel sample were placed in a 1 litre blaring blender jar, and mixed at maximum blender speed for 30 seconds. The resulting foam was poured into a 1000 ml graduated cylinder, and a timer started. The foam height is the maximum volume occupied by the foam, and can be used to calculate foam quality. The half life is the time required for 100 ml of solution to accumulate in the bottom of the cylinder. For elevated temperatures, the sample, blender j an, and cylinder are heated to 10 C above the tested temperature for 15 minutes. 1n the following examples, the percentages are by weight and the viscosity is measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at room temperature.
Example 1 0.50 g of N-hexadecyl dimethyl betaine having the formula CH3(CHZ)ls N+(CH3)2CH2COO-(hereinafter referred to as C16 -betaine or C,6-BET) was dissolved in 0.4 ml isopropanol (IPA) and then mixed with 200 ml of tap water. The resulting solution was mixed with 0.27g of the sodium salt of dodecyl benzene sulphonate having the formula CH12H25~6H4S03~1a+
(hereinafter referred to as Na-LAS). A clear gel with high elasticity was formed. The gel was poured into a 1 litre Waning blender jar, and mixed at maximum blender speed for 30 seconds.
The resulting foam was tested in the manner described above. The test results are listed in Table I
Example 2 O.SOg of C,6 -BET was dissolved in 0.4 ml IPA, and then mixed with 200 ml of 7.0 wt%
of aqueous KCI solution. The resulting solution was mixed with 0,.098 g of the sodium salt ~of 3-hydroxy-2-naphthalenecarboxylic acid, CloH6(OH)COONa, (in the following called Na-BON).
A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 3 0.60g of C18 -betaine (Ci8-BET) was first dissolved in 1 ml isopropanol and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution. The resulting solution was mixed with 0.098 g of Na-BON. A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 4 0.50 g C18-BET was dissolved in 200 ml of 7.wt% of aqueous KCI solution at 40 C and then mixed with 0.7~ g of sodium xylene sulfonate (in the following called Na-XS). A clear gel with high elasticity was formed. The gel was cooled to room temperature. The gel was tested in the same manner as in Example 1. The results are shown in Table I.
Example 5 200 ml of gel with the composition specified in Example 4 was first subjected to saturation of COZ and then tested in the same manner as in Example 1. No significant changes in viscosity and foam properties were observed.
Example 6 200 ml of gel with the composition specified in Example 4 was first subjected to saturation of N2 and then tested in the same manner as in Example 1. No significant changes in viscosity and foam properties were observed.
Composition Viscosity of Foam height Foam Half Life base (approximategel (ml) (min) (cp) by weight) (1) 35 600 22 0.25 C16-BET
0.075 Na-LAS
0.2 IPA
balance water (2) 250 400 70 0.25 C16-BET
0.049 Na-BON
0.2 Il'A
7 KCl balance of water (3) 350 300 7 0.30 C1g-BET
0.049 Na-BON
0.5 IPA
balance of water (4) 285 620 45 0.40 C1$-BET
0.25 Na-XS
7 KCl balance of water From the results for the above examples, it is evident that C~6-betaine and C,g-betaine in combination with an organic salt electrolyte has good foaming capability and can be used for foam fracturing applications.
Example 7 1.0 g of CI8-BET was dissolved in 0.4 ml of IPA, and then mixed with 200 ml of 7.0%wt% of aqueous KCL solution. The resulting solution was mixed with 0.17 g of Na-LAS. A clear gel with high elasticity was formed. The viscosity of the gel was tested in the manner described above, and the results are listed in Table 2.
Example 8 0.75 g of C16-BET was dissolved in 0.4 ml of IPA, and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution. The resulting solution was mixed with 0.27 of Na-BON in NaOH solution. A clear gel with high elasticity was formed. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
Example 9 0.50 g of C1$-BET was first dissolved in 0.5 ml IPA and then mixed with 200 ml of 7.0 wt% of aqueous KCI solution at 40 C. The resulting solution was mixed with 0.14 g of Na-BON
in NaOH solution. A clear gel with high elasticity was formed. The gel was cooled to room temperature and tested in the same manner as in Example 7. The results are shown in Table 2.
Example 10 1.0 g of C1g-BET was premixed with 0.8 ml of ethylene glycol monobutyl ether (EGMBE), 0.6 g of Na-XS and 0.4 ml of hot water. The resulting mixture was than mixed with 200 ml of 7.0 wt% of aqueous KCI solution at room temperature. A clear elastic gel was formed immediately. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
Example 11 0.75 g of C,g-BET was premixed with 0.8 ml of EGMBE, 0.6 g of Na-XS and 0.4 ml of hot water. The resulting mixture was then mixed with 200 ml of 7.0 wt% of aqueous KCl solution at room temperature. A clear elastic gel was formed immediately. The gel was tested in the same manner as in Example 7. The results are shown in Table 2.
TABLE
Compositions Viscosity of gels (approximate % by weight) (cp) (7) 240 0.5 C1g-BET
0.85 Na-LAS
0.201PA
7.0 KCL
balance of water (8) 1050 0.38 C16-BET
0.14 Na-BON
0.2 IPA
7.00 KCl balance of water (9) . 300 0.25 C18-BET
0.070 Na-BON
0.50 IPA
7.00 KCl balance of water (10) 855 0.50 C1g-BET
0.30 Na-XS
0.40 EGMBE
7.00 KCl balance of water (11) 570 0.38 C1$-BET
0.30 Na-XS
0.40 EGMBE
7.00 KCl balance of water Example 12 200 ml of gel with the composition specified in Table 2 for Example 10 was first subjected to saturation with COZ and then tested in the manner described above. No significant changes in viscosity and foam properties were observed.
Example 13 200 ml of gel with the composition specified in Table 2 for Example 10 was first subj ected to saturation with NZ and then tested in the manner described above. No significant changes in viscosity and foam properties were observed.
From the results of testing set out in Table 2 it is evident that combinations of a betaine surfactant and an organic electrolyte in the aqueous medium form clear gels with good viscoelastic properties. These gels can be used for hydraulic fracturing applications. For applications requiring higher viscosity, higher surfactant loading is generally required.
The foaming properties of the surfactant and organic alcohol compsoitions according to the present invention were tested by a simple method involving the measuring the viscosity of the gel.
Example 14 1.5 g active substance of octadecyl dimethyl betaine (in the following called betaine) was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution. The resulting surfactant solution was mixed with 0.8 g of hexadecanol at 55°C. A
clear gel with high elasticity was formed. the viscosity of the gel was measured using a Brookfield viscometer (Model LVT,Spindle 1 at 12 rpm) at 55°C. The results are listed in Table 3.
Example I S
1.5 g of C 18-betaine was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution.
The resulting surfactant solution was mixed with 0.6 g of tetradecanol at 40°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured suing a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 40°C. The results are listed in Table 3.
Example 16 1.5 g of C 18-betaine was first dissolved in 200 ml of 5 wt% KC 1 aqueous solution.
The resulting surfactant solution was mixed with 0.2 g of decanol at 30°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 30°C. The results are shown in Table 3.
Example 17 1.0 g of C18-betaine was first dissolved in 200 ml of 5 wt% KC1 aqueous solution.
The resulting surfactant solution was mixed with 0.5 g of benzyl alcohol at 22°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Spindle 1 at 12 rpm) at 22°C. The results are shown in Table 3.
Example 18 1.5 of C16-betaine was first dissolved in 200 ml of 5 wt% KC1 aqueous solution. The resulting surfactant solution was mixed with 0.6 g of benzyl alcohol at 22°C. A clear gel with high elasticity was formed. The viscosity of the gel was measured using a Brookfield viscometer (Model LVT, Speindle 1 at 12 rpm) at 22°C. The results are shown in Table 3.
Table 3 Compositions Viscosity of gels 1. C18-Betaine 0.78% 340 cp Hexadecanol 0.4%
KCl 5.0%
2. C18-Betaine 0.75% 470 cp Tetradecanol 0.3 KCl S.0%
3. C18-Betaine 0.75% 750 cp Decanol 0.1 KCl 5.0%
4. C18-Betaine 0.5% 660 cp Benzyl alcohol0.25%
KCl 5.0%
5. C16-Betaine 0.75% 220 cp Benzyl alcohol0.3%
KCl 5.0%
From the results of testing set out in Table 3 it is evident that combinations of a betaine surfactant and an organic electrolyte in the aqueous medium form clear gels with good viscoelastic properties. These gels can be used for hydraulic fracturing applications. For applications requiring higher viscosity, higher surfactant loading is generally required. The present fluid may also contain a gas, for example NZ or C02, and thereby be in the form of foams or energized fluids. In other words, the present fluid may also be utilized as a foamed water-based fracturing fluid in the presence of gas.
KCl 5.0%
From the results of testing set out in Table 3 it is evident that combinations of a betaine surfactant and an organic electrolyte in the aqueous medium form clear gels with good viscoelastic properties. These gels can be used for hydraulic fracturing applications. For applications requiring higher viscosity, higher surfactant loading is generally required. The present fluid may also contain a gas, for example NZ or C02, and thereby be in the form of foams or energized fluids. In other words, the present fluid may also be utilized as a foamed water-based fracturing fluid in the presence of gas.
Claims (73)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A viscoelastic surfactant based fracturing fluid comprising an aqueous medium, at least one betaine surfactant having a saturated, or unsaturated alkyl or acyl group containing 14-24 carbon atoms and a member selected from the group consisting of (a) at least one organic electrolyte having the general formula wherein R1 is a hydrophobic aromatic hydrocarbon group with 6-24 carbon atoms and A is a cationic monovalent group, and (b) at least one alcohol having the general formula wherein R2 is a hydrocarbon group with 6-24 carbon atoms.
2. The fracturing fluid of claim 1, including the betaine and the organic electrolyte, the surfactant having the general formula wherein R3 is an alkyl, alkylene or aryl group.
3. The fracturing fluid of claim 1, wherein said organic electrolyte is selected from the group consisting of sodium 3 hydroxy-2-naphthalenecarboxylate; sodium xylene sulphonate;
sodium cumene sulphonate; sodium salicylate, sodium dodecyl benzene sulphonate, sodium toluene sulphonate, sodium toluate, sodium benzene sulpbonate, sodium;
hexadecylbensensulphonate and sodium phenyl phosphate.
sodium cumene sulphonate; sodium salicylate, sodium dodecyl benzene sulphonate, sodium toluene sulphonate, sodium toluate, sodium benzene sulpbonate, sodium;
hexadecylbensensulphonate and sodium phenyl phosphate.
4. The fracturing fluid of claim 1, wherein said aqueous medium is selected from the group consisting of water, an aqueous solution of an inorganic salt, water and a lower alkanol, glycol or polyglycol and mixtures thereof.
5. The fracturing fluid of claim 2, wherein said alkyl group of the betaine surfactant contains 14-22 carbon atoms.
6. The fracturing fluid of claim 2, wherein said alkyl group of the betaine surfactant contains 14-22 carbon atoms and 1-2 double bonds.
7. The fracturing fluid of claim 2, wherein the acyl group of the betaine surfactant contains 14-22 carbon atoms.
8. The fracturing fluid of claim 2, wherein, the acyl group of said betaine contains 14-22 carbon atoms and 1-2 double bonds.
9. The fracturing fluid of claim 3, wherein tho acyl group of said betaine surfactant contains 14-22 carbon atoms and 1-2 double bonds,
10. The fracturing fluid of claim 1, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
11. The fracturing fluid of claim 1, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2-naphthalene carboxylic acid.
12. The fracturing fluid of claim 1, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2-naphthalenecarboxylic acid.
13. The fracturing flood of claim 1, wherein said aqueous medium is a water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
14. The fracturing fluid of claim 1, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
15. The fracturing fluid of claim 1, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
16. The fracture fluid of claim 1, wherein said aqueous medium is a solution of KCl is water and ethylene glycol monobutyl ether, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodim xylene sulphonate.
17. The fracturing fluid of claim 1, wherein said aqueous medium is a mixture of water and isopropanal, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulpltonate.
18. The fracturing fluid of claim 1, wherein said aqueous medium is a solution of KCI in water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2 naphthalene carboxylic acid.
19. The fracturing fluid of claim 1, wherein said aqueous medium is a solution of KCI
in water arid isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2-naphthalenecarboxylic acid.
in water arid isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2-naphthalenecarboxylic acid.
20. The fracturing fluid of claim 1, wherein said aqueous medium is a solution of KCI in water and isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
21. The fracturing fluid of claim 1, wherein said aqueous medium is water and isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
22. The fracturing fluid of claim 1, wherein said aqueous medium is a solution of KCI in water, said betainc surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
23. The fracturing fluid of claim 1, wherein the surfactant is used with the alcohol, and the betaine surfactant has the general formula wherein R3 is an alkyl, alkylene or aryl group, and R4 and R5 are hydrocarbon aliphatic or aromatic, straight or branched, saturated or unsaturated groups.
24. The fracturing fluid of claim 23, wherein the groups R1 and R2 contain 1-2 hydrophilic moieties selected from hydroxyl, ethoxy of propoxy.
25. The fracturing fluid of claim 23, wherein said alcohol is selected from the group consisting of benzyl alcohol, decanol, dodecanol or hexadecanol.
26. The fracturing fluid of claim 23, wherein said aqueous medium is selected from the group consisting of water, an aqueous solution of an inorganic salt, water and a lower alkanol, glycol or polyglycol and mixtures thereof.
27. The fracturing fluid of claim 23, wherein said betaine surfactant is selected from the group consisting of erucyl dimethyl betaine, docosyl dimethyl betaine, octadecyl dimethyl betaine cetyl dimethyl betaine, and tallow dimenthyl betaine and myristyl dimethyl betaine.
28. The fracturing fluid of claim 23, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is hexadecanol.
29. The fracturing fluid of claim 23, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is tetradecanol.
30. The fracturing fluid of claim 23. wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is decanol.
31. The fracturing fluid of. claim 23, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine sad said alcohol is benzyl alcohol.
32. The fracturing fluid of claim 23, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said alcohol is benzyl alcohol.
33. The fracturing fluid of claim 23, wherein said aqueous medium is a solution of KC1 in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is hexadecanol.
34. The fracturing fluid of claim 23, wherein said aqueous medium is a solution of KC1 in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is tetradecanol.
35. The fracturing fluid of claim 23, wherein said aqueous medium is a solution of KC1 in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is decanol.
36. The fracturing fluid of claim 23, wherein said aqueous medium is a solution of KC1 in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is benzyl alcohol.
37. The fracturing fluid of claim 23, wherein said aqueous medium is a solution of KC1 in water, said betaine surfactant is hexadecyl dimethyl betaine and said alcohol is benzyl alcohol.
38. A method of fracturing a subterranean formation comprising the step of injecting a viscoelastic surfactant based fracturing fluid into the formation at a pressure sufficient to initiate fracturing, said fluid including an aqueous medium, at least one betaine surfactant having a saturated or unsaturated alkyl or aryl group containing 14 - 24 carbon atoms and a member selected from the group consisting of (a) at least one organic electrolyte having the general formula wherein R1 is a hydrophobic aromatic hydrocarbon group with 6-24 carbon atoms and may also contain one or two hydrophilic moieties, and A is a cationic preferably monovalent group, and (b) at least one alcohol having the general formula wherein R2 is a hydrocarbon with 6-24 carbon atoms.
39. The method of claim 38, including the betaine and the organic electrolyte, the surfactant having the general formula wherein R3 is an alkyl, alkylene at aryl group.
40. The method of claim 38, wherein said organic electrolyte is selected form the group consisting of sodium xylene sulphonate; sodium cumene sulphonate; sodium salicylate, sodium dodecyl benzene sulphonate, sodium toluene sulphonate, sodium toluate, sodium benzene sulphonate, sodium; hexadecylbensensulphonate and sodium phenyl phosphate.
41. The method of claim 38, wherein said aqueous medium is selected from the group consisting of water, an aqueous solution of an inorganic.salt, water and a lower alkanol, glycol or polyglycol and mixtures thereof.
42. The method of clean 39, wherein said alkyl group of the betaine surfactant contains 14-22 carbon atoms.
43. The method of claim 39, wherein said alkyl group of the betaine surfactant contains 14-22 carbon atoms and 1-2 double bonds.
44. The method of claim 39, wherein the acyl group of the betaine surfactant contains 14-22 carbon atoms.
45. The method of claim 39, wherein the acyl group of said betaine surfactant contains 14-22 carbon atoms and 1-2 double bonds.
46. The method of claim 40, wherein said betaine surfactant is selected from the group consisting of hexadecyl dimethyl betaine octadecyl dimethyl betaine, erucyl dimethyl betaine and docosyl dimethyl betaine.
47. The method of claim 38, wherein said aqueous medium is water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium, salt of dodecyl benzene sulphonate.
48. The method of claim 38, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2-naphthalene carboxylic acid.
49. The method of claim 38, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy-2-naphthalenecarboxylic acid.
50. The method of claim 38, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
51. The method of claim 38, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
52. The method of claim 38, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
53. The method of claim 38, wherein said aqueous medium is a solution of KCI
in water and ethylene glycol monobutyl ether, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
in water and ethylene glycol monobutyl ether, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
54. The method of claim 38, wherein said aqueous medium is a mixture of water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
55. The method of claim 38, wherein said aqueous medium is a solution of KCI
in water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2 Daphthalene carboxylic acid.
in water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy 2 Daphthalene carboxylic acid.
56. The method of claim 38, wherein said aqueous medium is a solution of KCI
in water and isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy-2-naphthalcnecarhoxylic acid.
in water and isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is the sodium salt of 3-hydroxy-2-naphthalcnecarhoxylic acid.
57. The method of claim 38, wherein said aqueous medium is a solution of KCI
in water end isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
in water end isopropanol, said betaine surfactant is octadecyl dimethyl betaine and said organic electrolyte is sodium xylene sulphonate.
58. The method of claim 38, wherein said aqueous medium is water and isopropanol, said betaine surfactant is octadecyl dimethyl betaine and sad organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
59. The method of claim 38, wherein said aqueous medium is a solution of KCI
in water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
in water and isopropanol, said betaine surfactant is hexadecyl dimethyl betaine and said organic electrolyte is the sodium salt of dodecyl benzene sulphonate.
60. The method of claim 38, wherein the surfactant is used with the alcohol, and the betaine surfactant has the general formula]
¦
when R3 is an alkyl, alkylene or aryl group, and R4 and R5 are hydrocarbon aliphatic or aromatic, straight or branched, saturated or unsaturated groups.
¦
when R3 is an alkyl, alkylene or aryl group, and R4 and R5 are hydrocarbon aliphatic or aromatic, straight or branched, saturated or unsaturated groups.
61. The method of claim 60, wherein said alcohol is selected from the group consisting of benzyl alcohol, decanol, dodecanol or hexadecanol.
62. The method of claim 60, wherein said aqueous medium is selected from the group consisting of water, an aqueous solution of an inorganic salt, water and a lower alkanol, glycol or polyglycol and mixtures thereof.
63. The method of claim 60, wherein wherein said betaine surfactant is selected from the group consisting of erucyl dimethyl betaine, docosyl dimethyl betaine, octadecyl dimethyl betaine cetyl dimethyl betaine, and tallow dimenthyl betaine and myristyl dimethyl betaine.
64. The method of claim 60, wherein said aqueous medium is a solution of water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is hexadecanol.
65. The method of claim 60, wherein said aqueous medium is a solution of water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is tetradecanol.
66. The method of claim 60, wherein said aqueous medium is a solution of water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is decanol.
67. The method of claim 60, wherein said aqueous medium is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is benzyl alcohol.
68. The method of claim 60, wherein said aqueous medium is water, said betaine surfactant is hexadecyl dimethyl betaine and said alcohol is benzyl alcohol.
69. The method of claim 60, wherein said aqueous medium is a solution of KCI
in water, said betaine surfactant is octadecyl dimethyl betaine and-said alcohol is hexadecanol.
in water, said betaine surfactant is octadecyl dimethyl betaine and-said alcohol is hexadecanol.
70. The method of claim 60, wherein said aqueous medium is a solution of KCI
in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is tetradecanol.
in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is tetradecanol.
71. The method of claim 60, wherein said aqueous medium is a solution of KCI
in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is decanol.
in water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is decanol.
72. The method of claim 60, wherein said aqueous medium is a solution of KCI
is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is bentyl alcohol.
is water, said betaine surfactant is octadecyl dimethyl betaine and said alcohol is bentyl alcohol.
73. The method of claim 60, wherein said aqueous medium is a solution of KCI
in water, said betaine surfactant is hexadecyl dimethyl betaine and said alcohol is benzyl alcohol.
in water, said betaine surfactant is hexadecyl dimethyl betaine and said alcohol is benzyl alcohol.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002408052A CA2408052A1 (en) | 2000-05-03 | 2001-05-03 | Fracturing fluid |
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA2307435 | 2000-05-03 | ||
| CA2,307,435 | 2000-05-03 | ||
| CA002329600A CA2329600A1 (en) | 2000-12-22 | 2000-12-22 | Fracturing fluid |
| CA2,329,600 | 2000-12-22 | ||
| CA002408052A CA2408052A1 (en) | 2000-05-03 | 2001-05-03 | Fracturing fluid |
| PCT/CA2001/000597 WO2001083946A1 (en) | 2000-05-03 | 2001-05-03 | Fracturing fluid |
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| Publication Number | Publication Date |
|---|---|
| CA2408052A1 true CA2408052A1 (en) | 2001-11-08 |
Family
ID=27171242
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002408052A Abandoned CA2408052A1 (en) | 2000-05-03 | 2001-05-03 | Fracturing fluid |
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| Country | Link |
|---|---|
| CA (1) | CA2408052A1 (en) |
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| GB2440479A (en) * | 2005-05-02 | 2008-01-30 | Trican Well Serives Ltd | Method for making transportable aqueous slurries by particulate hydrophobicization |
| WO2007033489A3 (en) * | 2005-09-23 | 2007-05-18 | Trican Well Service Ltd | Slurry compositions and methods for making same |
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| CN117487535A (en) * | 2023-11-11 | 2024-02-02 | 荆州市吉通石油技术有限公司 | Preparation process of fracturing, acidifying, foaming and cleanup additive |
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