NO177012B - Water-based drilling fluid - Google Patents
Water-based drilling fluid Download PDFInfo
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- NO177012B NO177012B NO891023A NO891023A NO177012B NO 177012 B NO177012 B NO 177012B NO 891023 A NO891023 A NO 891023A NO 891023 A NO891023 A NO 891023A NO 177012 B NO177012 B NO 177012B
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- drilling fluid
- water
- drilling
- oil
- alcohol
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- 238000005553 drilling Methods 0.000 title claims description 82
- 239000012530 fluid Substances 0.000 title claims description 64
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims description 28
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 81
- 239000000839 emulsion Substances 0.000 claims description 25
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 20
- 150000003839 salts Chemical class 0.000 claims description 18
- 239000004927 clay Substances 0.000 claims description 6
- 239000003995 emulsifying agent Substances 0.000 claims description 6
- 229920000642 polymer Polymers 0.000 claims description 4
- FJNCXZZQNBKEJT-UHFFFAOYSA-N 8beta-hydroxymarrubiin Natural products O1C(=O)C2(C)CCCC3(C)C2C1CC(C)(O)C3(O)CCC=1C=COC=1 FJNCXZZQNBKEJT-UHFFFAOYSA-N 0.000 claims description 3
- 125000004432 carbon atom Chemical group C* 0.000 claims description 3
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims description 3
- 239000003921 oil Substances 0.000 description 24
- 239000004094 surface-active agent Substances 0.000 description 24
- 230000015572 biosynthetic process Effects 0.000 description 22
- 238000005755 formation reaction Methods 0.000 description 22
- 239000013505 freshwater Substances 0.000 description 22
- 230000008014 freezing Effects 0.000 description 12
- 238000007710 freezing Methods 0.000 description 12
- 150000004677 hydrates Chemical class 0.000 description 11
- 239000000654 additive Substances 0.000 description 10
- 238000005520 cutting process Methods 0.000 description 10
- 238000012360 testing method Methods 0.000 description 9
- 239000012085 test solution Substances 0.000 description 8
- 230000002195 synergetic effect Effects 0.000 description 7
- 150000001412 amines Chemical group 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000012065 filter cake Substances 0.000 description 4
- 239000002480 mineral oil Substances 0.000 description 4
- 235000010446 mineral oil Nutrition 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000007480 spreading Effects 0.000 description 4
- 238000003892 spreading Methods 0.000 description 4
- 239000003760 tallow Substances 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229920002134 Carboxymethyl cellulose Polymers 0.000 description 2
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 2
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- 229920002472 Starch Polymers 0.000 description 2
- 239000000440 bentonite Substances 0.000 description 2
- 229910000278 bentonite Inorganic materials 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 238000004945 emulsification Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 150000004676 glycans Chemical class 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 229920001282 polysaccharide Polymers 0.000 description 2
- 239000005017 polysaccharide Substances 0.000 description 2
- 230000000717 retained effect Effects 0.000 description 2
- JHJLBTNAGRQEKS-UHFFFAOYSA-M sodium bromide Chemical compound [Na+].[Br-] JHJLBTNAGRQEKS-UHFFFAOYSA-M 0.000 description 2
- 239000008107 starch Substances 0.000 description 2
- 235000019698 starch Nutrition 0.000 description 2
- 230000008961 swelling Effects 0.000 description 2
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229920001732 Lignosulfonate Polymers 0.000 description 1
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 125000005037 alkyl phenyl group Chemical group 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 235000011148 calcium chloride Nutrition 0.000 description 1
- 239000001768 carboxy methyl cellulose Substances 0.000 description 1
- 235000010948 carboxy methyl cellulose Nutrition 0.000 description 1
- 239000008112 carboxymethyl-cellulose Substances 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- -1 glycerol for example Chemical compound 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- DNIAPMSPPWPWGF-UHFFFAOYSA-N monopropylene glycol Natural products CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 1
- 230000002085 persistent effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000223 polyglycerol Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 235000013772 propylene glycol Nutrition 0.000 description 1
- 238000010561 standard procedure Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 229920003169 water-soluble polymer Polymers 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
- C09K8/02—Well-drilling compositions
- C09K8/04—Aqueous well-drilling compositions
- C09K8/14—Clay-containing compositions
- C09K8/18—Clay-containing compositions characterised by the organic compounds
- C09K8/22—Synthetic organic compounds
- C09K8/24—Polymers
-
- 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
- C09K2208/00—Aspects relating to compositions of drilling or well treatment fluids
- C09K2208/22—Hydrates inhibition by using well treatment fluids containing inhibitors of hydrate formers
Landscapes
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Colloid Chemistry (AREA)
- Earth Drilling (AREA)
- Drilling Tools (AREA)
- Perforating, Stamping-Out Or Severing By Means Other Than Cutting (AREA)
Description
Oppfinnelsen angår et vannbasert borefluid. Nærmere bestemt angår oppfinnelsen et vannbasert borefluid som har forbedrede egenskaper som tillater boreoperasjoner ved lave temperaturer, forhindrer dannelse av gasshydrater som dannes ved lave temperaturer og høye trykk, reduserer spredning av leirskifer, noe som resulterer i forbedret borehullstabilitet, reduserer væsketap og er miljøvennlig. The invention relates to a water-based drilling fluid. More specifically, the invention relates to a water-based drilling fluid that has improved properties that allow drilling operations at low temperatures, prevents the formation of gas hydrates that form at low temperatures and high pressures, reduces the spread of shale, which results in improved borehole stability, reduces fluid loss and is environmentally friendly.
Borefluider i form av olje-i-vann-emulsjoner (eller slam) inneholder vanligvis vann, olje, emulgator, leire eller polymerer og forskjellige additiver som regulerer borefluiders fysikalske, kjemiske og/eller reologiske egenskaper i borehull. Enhver type vandig borefluid kan omdannes til en borefluidemulsjon på den enkle måte at det tilsettes den ønskede mengde av olje og emulgator. Borefluidet tjener til å fjerne partikler, borekaks og lignende som produseres av en roterende borekrone, fra et borehull ved å sirkulere borefluidet nedover fra brønnens overflate, gjennom borestrengen og ut gjennom åpninger i borekronen, slik at borefluidet så sirkuleres opp-over i ringrommet mellom borehullets side og den roterende borestreng. Drilling fluids in the form of oil-in-water emulsions (or muds) usually contain water, oil, emulsifier, clay or polymers and various additives that regulate the physical, chemical and/or rheological properties of drilling fluids in boreholes. Any type of aqueous drilling fluid can be converted into a drilling fluid emulsion in the simple way of adding the desired amount of oil and emulsifier. The drilling fluid serves to remove particles, cuttings and the like that are produced by a rotating drill bit, from a borehole by circulating the drilling fluid downwards from the surface of the well, through the drill string and out through openings in the drill bit, so that the drilling fluid is then circulated upwards in the annulus between the borehole's side and the rotating drill string.
Utvelgelsen av et borefluid avhenger i første rekke av den geologiske formasjon hvor det bores og problemene i sammenheng med slike formasjoner. Det som i første rekke må tas hensyn til ved utvelgelsen av et borefluid er temperatur-betingelser ved boring, dannelse av gasshydrater, spredning av leirskifer, tap av borefluid og miljøkrav. Opprinnelig ble hensyntagen til temperatur ved boring av olje/gass-brønner forbundet med dype, varme brønner (>150°C). For boring på dypt vann og/eller i arktiske områder er lave temperaturer av be-tydning av to hovedgrunner: (1) boreslammet fryser på grunn av lav temperatur, spesielt hvis brønnen må avstenges i lengre tid, og (2) det dannes gasshydrater ved lave temperaturer og høye trykk etter innstrømmingen av gass. The selection of a drilling fluid depends primarily on the geological formation where it is drilled and the problems associated with such formations. What must primarily be taken into account when selecting a drilling fluid are temperature conditions during drilling, formation of gas hydrates, spreading of clay shale, loss of drilling fluid and environmental requirements. Originally, consideration of temperature when drilling oil/gas wells was associated with deep, hot wells (>150°C). For drilling in deep water and/or in arctic areas, low temperatures are important for two main reasons: (1) the drilling mud freezes due to the low temperature, especially if the well has to be shut down for a long time, and (2) gas hydrates are formed at low temperatures and high pressures after the inflow of gas.
Ved hjelp av den foreliggende oppfinnelse overvinnes disse og andre problemer, idet det tilveiebringes et borefluid som inneholder additiver som setter ned borefluidets frysepunkt i den hensikt å muliggjøre boreoperasjoner ved lave temperaturer, forhindre dannelse av gasshydrater som dannes ved lave temperaturer og høye trykk, forhindre spredning av leirskifer, noe som resulterer i øket borehullstabilitet, redusere tap av borefluid og derved redusere mengdene av andre additiver som forhindrer mulige væsketap (f.eks. gel-bentonitt, carboxymethylcellulose, stivelse) og er miljøvennlige. With the help of the present invention, these and other problems are overcome, as a drilling fluid is provided which contains additives which lower the freezing point of the drilling fluid with the intention of enabling drilling operations at low temperatures, preventing the formation of gas hydrates which are formed at low temperatures and high pressures, preventing spreading of shale, resulting in increased borehole stability, reducing drilling fluid loss and thereby reducing the amounts of other additives that prevent possible fluid loss (eg gel-bentonite, carboxymethylcellulose, starch) and are environmentally friendly.
Med oppfinnelsen tilveiebringes det således et vannbasert borefluid som inneholder vann, minst én av komponentene leire og polymer, emulgator og en olje-i-alkohol-emulsjon, og som er kjennetegnet ved at alkoholen har færre enn 8 hydroxygrupper og færre enn 16 carbonatomer, og at konsentrasjonen av alkohol er 1-60 vekt%, beregnet på borefluidets totalvekt. The invention thus provides a water-based drilling fluid which contains water, at least one of the components clay and polymer, emulsifier and an oil-in-alcohol emulsion, and which is characterized by the alcohol having fewer than 8 hydroxy groups and fewer than 16 carbon atoms, and that the concentration of alcohol is 1-60% by weight, calculated on the total weight of the drilling fluid.
Det nye borefluid inneholder en mengde av en alkohol, som for eksempel glycerol, og eventuelt et salt som er tilstrekkelig til å redusere borefluidets frysepunkt til en for-utbestemt verdi som vil motvirke de overfor omtalte mangler. The new drilling fluid contains an amount of an alcohol, such as glycerol for example, and possibly a salt which is sufficient to reduce the freezing point of the drilling fluid to a predetermined value which will counteract the deficiencies mentioned above.
Borefluidet er anvendelig ved en fremgangsmåte for å bore en brønn, som innebærer at en borestreng roteres for boring av et borehull inn i formasjonen; et boreslam sirkuleres gjennom borestrengen og gjennom ringrommet mellom borestrengen og borehullets vegg; borefluidet kontrolleres for tegn på noen av de følgende problemer: frysing, dannelse av gasshydrater, spredning av leirskifer og væsketap; og tilsetning av polyglycerol og eventuelt glycerol og/eller et salt til borefluidet i en mengde som er tilstrekkelig til å overvinne de problemer som er omtalt ovenfor. The drilling fluid is applicable in a method for drilling a well, which involves rotating a drill string to drill a borehole into the formation; a drilling mud is circulated through the drill string and through the annulus between the drill string and the borehole wall; the drilling fluid is checked for signs of any of the following problems: freezing, formation of gas hydrates, dispersion of shale and fluid loss; and adding polyglycerol and optionally glycerol and/or a salt to the drilling fluid in an amount sufficient to overcome the problems discussed above.
Oppfinnerne har således funnet at tilsetning av en alkohol som f.eks. glycerol og eventuelt et salt i en passende mengde til et vannbasert borefluid i betydelig grad senker frysepunktet på borefluidet og virker til å eliminere problemer med boreoperasjoner ved lav temperatur, forhindrer dannelse av gasshydrater som dannes ved lave temperaturer og høye trykk, forhindrer spredning av leirskifer, noe som resulterer i forbedret borehullstabilitet, reduserer tap av borefluid, noe som fører til at mengden av eventuelle andre additiver som reduserer tap av væske kan reduseres (f.eks. gelbentonitt, carboxymethylcellulose (CMC), stivelse) og er miljøvennlig. Borestrengen roteres således for boring av et borehull inn i formasjonen, mens et borefluid sirkulerer ned gjennom borestrengen og derfra opp gjennom ringrommet mellom borestrengen og borehullets vegg. Mens dette pågår, er det fordelaktig at en operatør kontrollerer eller observerer borefluidet for tegn på de forannevnte problemer. Alternativt kan det være kjent på forhånd at det foreligger spesielle problemer med formasjonen, og det vannbaserte borefluid i form av en olje-i-alkohol-emulsjon kan da benyttes for å overvinne disse problemer. The inventors have thus found that the addition of an alcohol such as glycerol and possibly a salt in an appropriate amount to a water-based drilling fluid significantly lowers the freezing point of the drilling fluid and acts to eliminate problems with drilling operations at low temperatures, prevents the formation of gas hydrates that form at low temperatures and high pressures, prevents the spread of shale, resulting in improved wellbore stability, reduces drilling fluid loss, which means that the amount of any other fluid loss reducing additives can be reduced (eg gel bentonite, carboxymethyl cellulose (CMC), starch) and is environmentally friendly. The drill string is thus rotated to drill a drill hole into the formation, while a drilling fluid circulates down through the drill string and from there up through the annulus between the drill string and the wall of the drill hole. While this is going on, it is advantageous for an operator to check or observe the drilling fluid for signs of the aforementioned problems. Alternatively, it may be known in advance that there are particular problems with the formation, and the water-based drilling fluid in the form of an oil-in-alcohol emulsion can then be used to overcome these problems.
I de fleste tilfelle vil de mengder av olje-i-alkohol-emulsjon, som eventult inneholder salt, som kan anvendes i det vannbaserte borefluid bestemmes fra brønn til brønn. En konsentrasjon av alkohol i det vannbaserte borefluid i form av en olje-i-alkohol-emulsjon på 1 - 60 vekt%, eller fortrinnsvis 5-40 vekt% (vekt% basert på den totale vekt av borefluidet), og eventuelt salt fra 1 til 26 vekt%, eller fortrinnsvis 5-20 vekt%, vil redusere frysepunktet til borefluidet med 1 - 40° C. En konsentrasjon på 1 - 60 vekt%, eller fortrinnsvis 10-40 vekt% alkohol, og eventuelt fra 1-26 vekt%, eller fortrinnsvis 5-26 vekt% salt, vil forhindre dannelse av gasshydrater. En konsentrasjon på 1- 60 vekt%, eller fortrinnsvis 5-30 vekt% alkohol, og eventuelt fra 1 - 26 vekt%, eller fortrinnsvis 5-20 vekt% salt i borefluidet vil forhindre spredning av leirskifer. En konsentrasjon av 1 - 60 vekt%, eller fortrinnsvis 5-40 vekt% alkohol i borefluidet og eventuelt salt fra 1-26 vekt%, eller fortrinnsvis 5-15 vekt%, vil redusere tap av væske fra borefluidet gjennom borehullets vegg. In most cases, the amounts of oil-in-alcohol emulsion, which may contain salt, that can be used in the water-based drilling fluid will be determined from well to well. A concentration of alcohol in the water-based drilling fluid in the form of an oil-in-alcohol emulsion of 1-60% by weight, or preferably 5-40% by weight (% by weight based on the total weight of the drilling fluid), and possibly salt from 1 to 26% by weight, or preferably 5-20% by weight, will reduce the freezing point of the drilling fluid by 1-40° C. A concentration of 1-60% by weight, or preferably 10-40% by weight of alcohol, and optionally from 1-26% by weight %, or preferably 5-26% by weight of salt, will prevent the formation of gas hydrates. A concentration of 1-60% by weight, or preferably 5-30% by weight of alcohol, and optionally from 1-26% by weight, or preferably 5-20% by weight of salt in the drilling fluid will prevent the spread of shale. A concentration of 1-60% by weight, or preferably 5-40% by weight of alcohol in the drilling fluid and possibly salt from 1-26% by weight, or preferably 5-15% by weight, will reduce loss of fluid from the drilling fluid through the wall of the borehole.
Forskjellige uorganiske salter er egnet for anvendelse ifølge oppfinnelsen. Disse omfatter, men er ikke begrenset til, NaCl, NaBr, KC1, CaCl2 og NaNC^. Blant disse foretrekkes NaCl. Erfaringer viser at en synergistisk effekt oppstår når et slikt salt brukes sammen med alkohol som en additivpakke for boreslam, dvs. at effekten er større enn summen av effektene av salt og alkohol hver for seg. Various inorganic salts are suitable for use according to the invention. These include, but are not limited to, NaCl, NaBr, KCl, CaCl2 and NaNC^. Among these, NaCl is preferred. Experience shows that a synergistic effect occurs when such a salt is used together with alcohol as an additive package for drilling mud, i.e. that the effect is greater than the sum of the effects of salt and alcohol separately.
Alkoholen som anvendes i henhold til oppfinnelsen kan være hvilket som helst alkohol med mindre enn 8 hydroxygrupper og mindre enn 16 carbonatomer. Glycerol er mest foretrukket. Eksempler på andre alkoholer som kan benyttes omfatter isopropanol, ethylenglycol og 1,2-propandiol. The alcohol used according to the invention can be any alcohol with less than 8 hydroxy groups and less than 16 carbon atoms. Glycerol is most preferred. Examples of other alcohols that can be used include isopropanol, ethylene glycol and 1,2-propanediol.
I henhold til oppfinnelsen kan enhver type vannbasert borefluid omdannes til en borefluidemulsjon ved tilsetting av den ønskede mengde olje, emulgator (overflateaktive midler) og alkohol (for eks. glycerol). According to the invention, any type of water-based drilling fluid can be converted into a drilling fluid emulsion by adding the desired amount of oil, emulsifier (surfactant) and alcohol (e.g. glycerol).
Borefluider i form av emulsjoner har mange fordeler fremfor vanlige borefluider. Fordelene omfatter, men er ikke begrenset til, øket borehastighet, lengre levetid for borekronen, færre rundtripper (dvs. det å ta boret helt opp og så ned igjen etter for eks. å ha skiftet borekrone), færre tiltrekninger på røret, mindre motstand i røret og forbedrede betingelser i hullet. Drilling fluids in the form of emulsions have many advantages over ordinary drilling fluids. The advantages include, but are not limited to, increased drilling speed, longer life of the drill bit, fewer trippings (i.e. taking the drill all the way up and then down again after e.g. changing the drill bit), fewer pulls on the pipe, less resistance in the pipe and improved conditions in the hole.
Emulgatorer (overflateaktive midler) som foretrekkes anvendt ved den foreliggende fremgangsmåte er dikvartære aminer, alkylfenyl-ethoxylater, alkohol-ethoxylater og amin-ethoxylater. I henhold til foreliggende oppfinnelse er det meget å foretrekke at en emulsjon av oljen, overflateaktivt middel og alkohol (for eks. glycerol) fremstilles først. Denne emulsjon emulgeres eller blandes så med vann. Emulgeringen foretas fortrinnsvis ved mekanisk bevegelse. Emulsifiers (surfactants) which are preferably used in the present method are diquaternary amines, alkylphenyl ethoxylates, alcohol ethoxylates and amine ethoxylates. According to the present invention, it is highly preferable that an emulsion of the oil, surfactant and alcohol (for example glycerol) is prepared first. This emulsion is then emulsified or mixed with water. The emulsification is preferably carried out by mechanical movement.
Et borefluids egenskaper bør være slik at borefluidet fremmer sikker og hurtig boring, samt ferdigstillelse av brønnen med maksimal produsjonskapasitet. Bruk av borefluider i form av emulsjoner med kontrollerte egenskaper medfører store utgifter, og for å utføre sin funksjon på en korrekt måte må borefluidet beskyttes mot virkningene av betingelser som frysing, dannelse av gasshydrater, spredning av leirskifer og væsketap. Bruk av alkohol/olje-emulsjon i et vannbasert borefluid som eventuelt inneholder salt beskytter uten vanskelighet borefluidet mot frysing og dannelse av gasshydrater ved at borefluidets frysepunkt senkes. A drilling fluid's properties should be such that the drilling fluid promotes safe and rapid drilling, as well as completion of the well with maximum production capacity. The use of drilling fluids in the form of emulsions with controlled properties entails large expenses, and in order to perform its function correctly, the drilling fluid must be protected against the effects of conditions such as freezing, formation of gas hydrates, spreading of shale and fluid loss. Using an alcohol/oil emulsion in a water-based drilling fluid that may contain salt easily protects the drilling fluid against freezing and the formation of gas hydrates by lowering the freezing point of the drilling fluid.
Når det gjelder spredning av leirskifer samt væsketap, understøtter bruken av alkohol/olje-emulsjon i et vannbasert borefluid, eventult inneholdende salt, avset- When it comes to the spread of shale as well as fluid loss, the use of alcohol/oil emulsion in a water-based drilling fluid, possibly containing salt, supports the
ningen av en ugjennomtrengelig filterkake, og filterkaken forhindrer videre væsketap og spredning av leirskifer. Filterkaken virker i første rekke på grunn av dens ugjennomtrengelighet for vann. Dersom både formasjonens gjennomtrengelighet og væsketapsegenskapene for boreslammet er høye, vil store mengder væske strømme gjennom veggkaken og inn i den gjennomtrengelige formasjon og etterlate en tykk veggkake. the formation of an impermeable filter cake, and the filter cake further prevents fluid loss and the spread of shale. The filter cake works primarily because of its impermeability to water. If both the permeability of the formation and the fluid loss properties of the drilling mud are high, large quantities of fluid will flow through the wall cake and into the permeable formation, leaving behind a thick wall cake.
Denne kaken kan bli så tykk at den i vesentlig grad influerer på bevegelsen av borerøret når det trekkes tilbake og kan til og med resultere i at røret setter seg fast. Dersom en tykk kake dannes i forkant av den produserende formasjon, kan det hende at den ikke blir fjernet helt ved prosessen ved brønnens ferdigstillelse og den kan ha innflytelse på produksjonshas-tigheten for brønnen. Væsken som går inn i formasjonen kan også ha innflytelse. Dersom borefluidet er vannbasert og det bores i leirskifer og leire hvor det er mistanke om hydratdannelse, kan benyttelsen av borefluider med høyt væsketap resultere i at leirskiferen svulmer opp og blir tyngre, borehastigheten blir lavere, røret sitter fast, utfiskingsarbeider og til og med tap av hullet. Dersom den produserende formasjon inneholder leirer som kan danne hydrater, kan inntrengning av vann resultere i oppsvulming av leirpartiklene i den sandige formasjon og vedvarende tap av gjennomtrengelighet vil resultere i forringede produk-sjonsmengder. Tilsetningene som anvendes i det vannbaserte fluid ifølge oppfinelsen, løser lett slike problemer ved å øke filterkakens ugjennomtrengelighet for vann og derved minske borefluidets væsketapsegenskaper. This cake can become so thick that it significantly affects the movement of the drill pipe when it is withdrawn and can even result in the pipe sticking. If a thick cake is formed in front of the producing formation, it may not be completely removed during the well completion process and it may have an influence on the production rate for the well. The fluid entering the formation can also have an influence. If the drilling fluid is water-based and drilling is carried out in shale and clay where hydrate formation is suspected, the use of drilling fluids with high fluid loss can result in the shale swelling and becoming heavier, the drilling speed being lower, the pipe sticking, fishing out work and even loss of the hole. If the producing formation contains clays that can form hydrates, ingress of water can result in swelling of the clay particles in the sandy formation and persistent loss of permeability will result in reduced production quantities. The additives used in the water-based fluid according to the invention easily solve such problems by increasing the impermeability of the filter cake to water and thereby reducing the fluid loss properties of the drilling fluid.
De følgende eksempler illustrerer borefluidet ifølge oppfinnelsen. The following examples illustrate the drilling fluid according to the invention.
Tester for spredning av borekaks hvis resultater Tests for dispersion of drilling cuttings if results
er vist i tabell 1 og tabell 2, ble utført på følgende måte: Testevæsker og leirskiferborekaks av en bestemt størrelse (6 - 10 mesh) ble varmvalset i 45 sekunder ved 65° C. Etter varmvalsingen av leirskifer-testblandingen ble leirskiferen sortert ved hjelp av 10-, 30- og 80-mesh sikter og ble tørket. Resultatene er uttrykt som restprosent av den opprinnelige vekt (2,5 gram), og er vist i kolonnen "Eksper.". is shown in Table 1 and Table 2, was carried out as follows: Test fluids and shale drill cuttings of a certain size (6 - 10 mesh) were hot rolled for 45 seconds at 65° C. After the hot rolling of the shale test mixture, the shale was sorted using 10-, 30- and 80-mesh sieves and were dried. The results are expressed as a residual percentage of the original weight (2.5 grams), and are shown in the "Exper." column.
Ferskvannet (FV) og den 0,150-m NaCl-oppløsning (NaCl) inneholdt 0,57 g/l XC-polymer som er et vannoppløselig polysaccharid, solgt under handelsnavnet "Kelzan XC" av Kelco Corp. for viskositetskontroll. Følgelig hadde alle testoppløsningene en viskositet på 2,0 centipoise målt med et Fann 35A viskosimeter. The fresh water (FV) and the 0.150 m NaCl solution (NaCl) contained 0.57 g/l XC polymer which is a water-soluble polysaccharide, sold under the trade name "Kelzan XC" by Kelco Corp. for viscosity control. Accordingly, all test solutions had a viscosity of 2.0 centipoise as measured by a Fann 35A viscometer.
Prosentene er alltid volumprosenter (v.%). "0" henviser til mineralolje brukt i forsøkene, "S" henviser til et ethoxylert talg-amin brukt som overflateaktivt middel i forsøkene, og "G" henviser til glycerol. The percentages are always volume percentages (v.%). "0" refers to mineral oil used in the experiments, "S" refers to an ethoxylated tallow amine used as a surfactant in the experiments, and "G" refers to glycerol.
I tabell 1 er det vist data som indikerer at tilsetningen av glycerol, olje og overflateaktivt middel forsterker ytelsen når det gjelder forhindring av borekaks-spredning. Hver av komponentene olje, overflateaktivt middel og glycerol ble tilsatt hver for seg til ferskvann eller ferskvann med NaCl. For å bedømme den synergistiske effekt, ble prosenten av leirskifer som var igjen i ferskvannet trukket fra alle de andre testoppløsningene (resultatene er vist i kolonnen "Korr."). For å bestemme synergien mellom olje, overflateaktivt middel og glycerol, ble restprosenten (minus restprosenten i ferskvannet) av glycerol/ferskvann, olje/ferskvann og overflateaktivt middel/ferskvann, addert. Resultatet er en beregnet restverdi på 4,9%, se kolonne "Ber.". Dette er betydelig mindre enn det en fikk når alle tre komponentene ble tilsatt til den samme testoppløsning. Table 1 shows data indicating that the addition of glycerol, oil and surfactant enhances the performance in terms of preventing drilling cuttings spreading. Each of the components oil, surfactant and glycerol was added separately to fresh water or fresh water with NaCl. To judge the synergistic effect, the percentage of shale remaining in the fresh water was subtracted from all the other test solutions (the results are shown in the "Corr." column). To determine the synergy between oil, surfactant and glycerol, the residual percentage (minus the residual percentage in fresh water) of glycerol/freshwater, oil/freshwater and surfactant/freshwater were added. The result is a calculated residual value of 4.9%, see column "Ber.". This is considerably less than what was obtained when all three components were added to the same test solution.
Når salt var tilstede, ble det funnet at restprosenten av de enkelte komponenter (glycerol, olje og overflateaktivt middel) i ferskvann (minus restprosenten i ferskvann) pluss NaCl i ferskvann (minus restprosenten i ferskvann) var en restprosent på 37,6. Dette var betydelig mindre enn det som ble observert når alle fire reagenser var i den samme testoppløsning. Disse resultater tyder på en synergistisk virkning av de forskjellige additiver som ble testet. When salt was present, it was found that the residual percentage of the individual components (glycerol, oil and surfactant) in fresh water (minus the residual percentage in fresh water) plus NaCl in fresh water (minus the residual percentage in fresh water) was a residual percentage of 37.6. This was significantly less than what was observed when all four reagents were in the same test solution. These results suggest a synergistic effect of the different additives that were tested.
Testresultatene vist i tabell 1 tyder på at kombina-sjonen av disse additiver ikke bare var en forbedring, men også synergistisk når det gjelder å forhindre spredning av leirskifer. The test results shown in Table 1 indicate that the combination of these additives was not only an improvement, but also synergistic when it comes to preventing the spread of shale.
Som en fremgangsmåte for forbedring av additivenes emulgering, ble det før tilsetting av fersk- eller saltvann fremstilt en emulsjon av mineralolje, glycerol og som overflateaktivt middel et ethoxylert talgsyreamin. Emulsjonen olje/overflateaktivt middel/glycerol, i tabellene oppført som O/G/S, ble fremstilt i et forhold 24/75/1 volum%. Denne emulsjon var stabil i ukesvis ved romtemperatur. Denne emulsjons effektivitet når det gjelder forhindring av spredning av borekaks er vist i tabell 2. As a method for improving the emulsification of the additives, before the addition of fresh or salt water, an emulsion of mineral oil, glycerol and, as a surfactant, an ethoxylated tallow amine was prepared. The oil/surfactant/glycerol emulsion, listed in the tables as O/G/S, was prepared in a ratio of 24/75/1% by volume. This emulsion was stable for weeks at room temperature. The effectiveness of this emulsion in preventing the spread of drilling cuttings is shown in Table 2.
Emulsjonen ble testet med henblikk på forhindring av spredning av borekaks (tabell 2) fra to typer leirskifer. Resultatene indikerer at emulsjonen på en effektiv måte forhindrer spredning av leirskifer, og at det eksisterer et synergistisk forhold mellom tilstedeværelsen av glycerol og olje/overflateaktivt middel. The emulsion was tested with a view to preventing the spread of drilling cuttings (table 2) from two types of shale. The results indicate that the emulsion effectively prevents the spread of shale, and that a synergistic relationship exists between the presence of glycerol and oil/surfactant.
For å bedømme de synergistiske effekter, ble prosentinnholdet av leirskifer som var igjen i ferskvannet subtrahert fra alle de.andre testoppløsninger. For bestem-melse av synergi mellom olje, overflateaktivt middel og glycerol ble den restprosenten (minus restprosent i ferskvann, se kolonne "Korr;") av glycerol/ferskvann, olje/ ferskvann og overflateaktivt middel/ferskvann addert. Dette resultat er den beregnede verdi, se kolonne "Ber.". Denne verdi er tydelige lavere enn det som ble oppnådd når alle tre komponentene var i den samme testoppløsning. To judge the synergistic effects, the percentage of shale remaining in the fresh water was subtracted from all the other test solutions. To determine the synergy between oil, surfactant and glycerol, the residual percentage (minus residual percentage in fresh water, see column "Corr;") of glycerol/fresh water, oil/fresh water and surfactant/fresh water was added. This result is the calculated value, see column "Ber.". This value is clearly lower than what was obtained when all three components were in the same test solution.
Når salt var tilstede, ble det funnet at restpro-sentmengden av de enkelte komponenter (glycerol, olje og overflateaktivt middel) i ferskvann (minus restprosenten i ferskvann) pluss NaCl i ferskvann (minus restprosenten i ferskvann) representerte den beregnede gjenværende prosentmengde. Denne var tydelig mindre enn det som ble observert når alle fire reagenser var i den samme testoppløsning. Disse resultater tyder på at det er et synergistisk forhold mellom de forskjellige additiver som ble testet. When salt was present, it was found that the residual percentage of the individual components (glycerol, oil and surfactant) in fresh water (minus the residual percentage in fresh water) plus NaCl in fresh water (minus the residual percentage in fresh water) represented the calculated residual percentage. This was clearly less than what was observed when all four reagents were in the same test solution. These results suggest that there is a synergistic relationship between the different additives that were tested.
Tabell 3 viser resultatene av spredningstestene Table 3 shows the results of the dispersion tests
for borekaks for Pierre leirskifer. Borekaks av størrelses-orden 6-10 mesh ble valset i testvæsken i 15 sekunder ved 65° C. Blandingen av testoppløsningen av leirskiferen sorteres så over 10-, 30- og 80-mesh sikter. Mengden som ble holdt tilbake på siktene adderes, og den tilbakeholdte prosentmengde beregnes i forhold til det opprinnelige utgangsmateriale (2,5 gram). Alle prøver ble varmvalset ved 65° C i den tid som er nevnt. for drill cuttings for Pierre shale. Drill cuttings of the order of 6-10 mesh were rolled in the test fluid for 15 seconds at 65° C. The mixture of the test solution of the shale is then sorted over 10-, 30- and 80-mesh sieves. The amount that was retained on the sieves is added, and the percentage amount retained is calculated in relation to the original starting material (2.5 grams). All samples were hot-rolled at 65° C for the time mentioned.
O/S benyttes som henvisning til 10 volumdeler mineralolje og 1 volumdel av et ethyoxylert talgsyreamin som overflateaktivt middel. O/S/G benyttes som henvisning til 6 volumdeler mineralolje, 93 volumdeler glycerol og 1 volumdel av et ethoxylert talgsyreamin som overflateaktivt middel. XC er en vannoppløselig polymer som inneholder polysaccharider, og som selges under handelsnavnet "Kelzan XC" av Kelco Corp. 20% NaCl er en oppløsning med 20 vekt% NaCl. O/S is used as a reference to 10 parts by volume of mineral oil and 1 part by volume of an ethoxylated tallow amine as surfactant. O/S/G is used as a reference to 6 parts by volume of mineral oil, 93 parts by volume of glycerol and 1 part by volume of an ethoxylated tallow amine as surfactant. XC is a water-soluble polymer containing polysaccharides sold under the trade name "Kelzan XC" by Kelco Corp. 20% NaCl is a solution with 20% NaCl by weight.
Tabell 3a viser en sammenligning av de forskjellige systemers evne til å forhindre spredning av borekaks fra Pierre leirskifer. Resultatene indikerer at glycerol/olje/ overflateaktivt middel er overlegent i forhold til alle de andre systemer for forhindring av spredning av borekaks fra denne leirskifer. Table 3a shows a comparison of the different systems' ability to prevent the spread of drilling cuttings from Pierre shale. The results indicate that glycerol/oil/surfactant is superior to all the other systems for preventing the spread of drilling cuttings from this shale.
Tabell 4 angir data for senkningen av frysepunktet som indikerer at blandingen olje/glycerol/overflateaktivt middel senker frysepunktet på ferskvann og saltvann. Dette resultat tyder på at denne emulsjon kan brukes for å forhindre frysing av boreslam i kalde omgivelser. I tillegg tyder det på at denne emulsjon vil redusere sannsynligheten for dannelse av gasshydrater i borefluidet. 20% NaCl er en oppløsning med 20 vekt% NaCl. Denne oppløsning ble blandet i volumforhold med emulsjonen olje/glycerol/overflateaktivt middel. Emulsjonen olje/glycerol/overflateaktivt middel inneholder 94 volum% glycerol, 5 volum% olje og 1 volum% overflateaktivt middel. Frysepunktet ble bestemt ifølge ASTM D-1177-metoden. Table 4 gives data for the lowering of the freezing point which indicates that the mixture oil/glycerol/surfactant lowers the freezing point of fresh water and salt water. This result suggests that this emulsion can be used to prevent freezing of drilling mud in cold environments. In addition, it suggests that this emulsion will reduce the probability of formation of gas hydrates in the drilling fluid. 20% NaCl is a solution with 20% NaCl by weight. This solution was mixed in volume ratio with the oil/glycerol/surfactant emulsion. The oil/glycerol/surfactant emulsion contains 94 vol% glycerol, 5 vol% oil and 1 vol% surfactant. The freezing point was determined according to the ASTM D-1177 method.
I tabell 5 presenteres data som viser at emulsjonen glycerol/olje/overflateaktivt middel kan benyttes i en Table 5 presents data showing that the emulsion glycerol/oil/surfactant can be used in a
boreslamformulering uten alvorlig endring av de opprinnelige reologiske egenskaper eller væsketapsegenskaper. Olje/glycerol/overf lateaktivt middel (O/G/S) ble emulgert i et forhold drilling mud formulation without serious alteration of the original rheological properties or fluid loss properties. Oil/glycerol/surfactant (O/G/S) was emulsified in a ratio
på 5/94/1 volum%. Resinex er en vannløselig, varmestabil, syntetisk harpiks brukt mot væsketap ved høy temperatur solgt av MI Drilling Fluid Company. CLS benyttes som uttrykk for krom-lignosulfonat. of 5/94/1% by volume. Resinex is a water soluble, heat stable, synthetic resin used against high temperature fluid loss sold by MI Drilling Fluid Company. CLS is used as an expression for chromium lignosulfonate.
Væsketapstesten og testen for høyt trykk og for høy temperatur (HPHT) er beskrevet i API standard prosedyrene for felttesting av borefluid (RP 13B). Dette dokument beskriver videre bestemmelsesmetodene for skjærspenningen ved 600 RPM og ved 300 RPM (i lb/100 ft<2>), den plastiske viskositet (PV), flytegrense og gelstyrke etter 10 sekunder og etter 10 minutter (i lb/100 ft<2>). Et Fann 35A-viskosimeter benyttes. The fluid loss test and the high pressure and high temperature (HPHT) test are described in the API standard procedures for field testing of drilling fluids (RP 13B). This document further describes the determination methods for the shear stress at 600 RPM and at 300 RPM (in lb/100 ft<2>), the plastic viscosity (PV), yield strength and gel strength after 10 seconds and after 10 minutes (in lb/100 ft<2 >). A Fann 35A viscometer is used.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US16776888A | 1988-03-14 | 1988-03-14 |
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| NO891023D0 NO891023D0 (en) | 1989-03-09 |
| NO891023L NO891023L (en) | 1989-09-15 |
| NO177012B true NO177012B (en) | 1995-03-27 |
| NO177012C NO177012C (en) | 1995-07-05 |
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| Application Number | Title | Priority Date | Filing Date |
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| US5085282A (en) * | 1988-03-14 | 1992-02-04 | Shell Oil Company | Method for drilling a well with emulsion drilling fluids |
| US5083622A (en) * | 1988-03-14 | 1992-01-28 | Shell Oil Company | Method for drilling wells |
| US5072794A (en) * | 1988-09-30 | 1991-12-17 | Shell Oil Company | Alcohol-in-oil drilling fluid system |
| US5260269A (en) * | 1989-10-12 | 1993-11-09 | Shell Oil Company | Method of drilling with shale stabilizing mud system comprising polycyclicpolyetherpolyol |
| US5058679A (en) * | 1991-01-16 | 1991-10-22 | Shell Oil Company | Solidification of water based muds |
| US5423379A (en) * | 1989-12-27 | 1995-06-13 | Shell Oil Company | Solidification of water based muds |
| US5673753A (en) * | 1989-12-27 | 1997-10-07 | Shell Oil Company | Solidification of water based muds |
| US5076364A (en) * | 1990-03-30 | 1991-12-31 | Shell Oil Company | Gas hydrate inhibition |
| US5076373A (en) * | 1990-03-30 | 1991-12-31 | Shell Oil Company | Drilling fluids |
| US5371244A (en) * | 1991-03-19 | 1994-12-06 | Shell Oil Company | Polycondensation of dihydric alcohols and polyhydric alcohols and thermal condensation to form polyethercyclicpolyols |
| US5302728A (en) * | 1991-03-19 | 1994-04-12 | Shell Oil Company | Polycondensation of phenolic hydroxyl-containing compounds and polyhydric alcohols and thermal condensation to form polyethercyclipolyols |
| US5302695A (en) * | 1991-03-19 | 1994-04-12 | Shell Oil Company | Polycondensation of epoxy alcohols with polyhydric alcohols and thermal condensation to form polyethercyclicpolyols |
| US5338870A (en) * | 1991-03-19 | 1994-08-16 | Shell Oil Company | Thermal condensation of polyhydric alcohols to form polyethercyclicpolyols |
| US5371243A (en) * | 1992-10-13 | 1994-12-06 | Shell Oil Company | Polyethercyclicpolyols from epihalohydrins, polyhydric alcohols, and metal hydroxides |
| US5286882A (en) * | 1992-10-13 | 1994-02-15 | Shell Oil Company | Polyethercyclicpolyols from epihalohydrins, polyhydric alcohols and metal hydroxides or epoxy alcohol and optionally polyhydric alcohols with addition of epoxy resins |
| US5428178A (en) * | 1992-10-13 | 1995-06-27 | Shell Oil Company | Polyethercyclipolyols from epihalohydrins, polyhydric alcohols, and metal hydroxides or epoxy alcohols and optionally polyhydric alcohols with thermal condensation |
| FR2697264B1 (en) * | 1992-10-23 | 1994-12-30 | Inst Francais Du Petrole | Method for reducing the tendency for hydrates to agglomerate in production effluents. |
| WO1994024413A1 (en) * | 1993-04-08 | 1994-10-27 | Bp Chemicals Limited | Method for inhibiting solids formation and blends for use therein |
| WO1994025727A1 (en) * | 1993-05-04 | 1994-11-10 | Bp Exploration Operating Company Limited | Hydrate inhibition |
| WO2004111161A1 (en) * | 2003-06-06 | 2004-12-23 | Akzo Nobel N.V. | Gas hydrate inhibitors |
| US10899955B2 (en) | 2014-12-31 | 2021-01-26 | Kemira Oyj | Emulsions, treatment fluids and methods for treating subterranean formations |
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| US4780220A (en) * | 1987-05-26 | 1988-10-25 | Hydra Fluids, Inc. | Drilling and completion fluid |
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| GB8905501D0 (en) | 1989-04-19 |
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| NO891023L (en) | 1989-09-15 |
| GB2216573A (en) | 1989-10-11 |
| NO891023D0 (en) | 1989-03-09 |
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