WO2013093388A1 - Polymère cellulosique modifié pour l'amélioration des fluides de forage de puits - Google Patents

Polymère cellulosique modifié pour l'amélioration des fluides de forage de puits Download PDF

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Publication number
WO2013093388A1
WO2013093388A1 PCT/GB2011/001750 GB2011001750W WO2013093388A1 WO 2013093388 A1 WO2013093388 A1 WO 2013093388A1 GB 2011001750 W GB2011001750 W GB 2011001750W WO 2013093388 A1 WO2013093388 A1 WO 2013093388A1
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Prior art keywords
fluid
drilling
completion
cellulose ether
workover
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PCT/GB2011/001750
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English (en)
Inventor
Ryan G. Ezell
Original Assignee
Haliburton Energy Services, Inc.
Turner, Craig Robert
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Haliburton Energy Services, Inc., Turner, Craig Robert filed Critical Haliburton Energy Services, Inc.
Priority to PCT/GB2011/001750 priority Critical patent/WO2013093388A1/fr
Priority to MX2013001747A priority patent/MX2013001747A/es
Priority to EP11805561.5A priority patent/EP2794808A1/fr
Priority to EA201390289A priority patent/EA201390289A8/ru
Priority to CA2807827A priority patent/CA2807827A1/fr
Priority to AU2011379603A priority patent/AU2011379603A1/en
Publication of WO2013093388A1 publication Critical patent/WO2013093388A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/02—Well-drilling compositions
    • C09K8/04—Aqueous well-drilling compositions
    • C09K8/06—Clay-free compositions
    • C09K8/08—Clay-free compositions containing natural organic compounds, e.g. polysaccharides, or derivatives thereof
    • C09K8/10—Cellulose or derivatives thereof
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
    • C08L1/08—Cellulose derivatives
    • C08L1/26—Cellulose ethers
    • C08L1/28—Alkyl ethers
    • C08L1/284—Alkyl ethers with hydroxylated hydrocarbon radicals

Definitions

  • the present invention relates to methods for treating subterranean formations. More particularly, the present invention relates to drilling, completion, or workover fluids that comprise nonionic cellulose ether polymers and their use in subterranean applications.
  • viscosified fluids are used in drilling fluids, completion fluids, workover fluids, as well as other treating fluids.
  • drilling fluid refers to any of a number of liquid and gaseous fluids and mixtures of fluids and solids (as solid suspensions, mixtures and emulsions of liquids, gases and solids) used in operations to drill boreholes into the earth.
  • drilling fluid includes "drill-in fluids.”
  • completion fluid refers to a fluid with a low solids content that may be used to "complete" an oil or gas well, for example, to facilitate final operations prior to initiation of production, such as setting screens production liners, packers, downhole valves or shooting perforations into the producing zone.
  • a completion fluid may be used to control a well should downhole hardware fail, without damaging the producing formation or completion components.
  • workover fluid refers to well- control fluids, for example a brine, that is used during workover operations.
  • Polymeric viscosifying agents such as cellulose derivatives, guar gums, biopolymers, polysaccharides, synthetic polymers, and the like, have previously been added to treatment fluids to obtain a desired viscosity.
  • Viscoelastic surfactants have also been added to treatment fluids to increase the viscosity thereof. Maintaining sufficient viscosity in these treatment fluids may be important for a number of reasons. For example, maintaining sufficient viscosity is important in drilling operations, for example, to provide hydrostatic pressure to prevent formation fluids from entering into the well bore, keep the drill bit cool and clean during drilling, carry out drill cuttings, and suspend the drill cuttings while drilling is paused and when the drilling assembly is brought in and out of the hole.
  • a treatment fluid of a sufficient viscosity may be used to divert the flow of fluids present within a subterranean formation (e.g. , formation fluids, other treatment fluids) to other portions of the formation, for example, by "plugging" an open space within the formation.
  • a subterranean formation e.g. , formation fluids, other treatment fluids
  • cellulose-based viscosifying agents are generally not believed to be thermally stable and easily solubilized.
  • Biopolymers are frequently used instead of cellulose in treatment fluids due to their favorable water solubility and thermal stability, however, use of such biopolymers can be problematic because they leave residue behind.
  • remedial treatments may be required to remove the residue so that the wells may be placed into production.
  • a chemical breaker such as an acid, oxidizer, or enzyme may be used to either dissolve the solids or reduce the viscosity of the treatment fluids.
  • use of a chemical breaker to remove the residue from inside the well bore and/or the formation matrix may be ineffective due to the properties of such biopolymers.
  • excessive use of chemical breakers to degrade such polymers may be corrosive to downhole tools and may leak off into the formation, carrying undissolved fines that may plug and/or damage the formation or may produce undesirable reactions with the formation.
  • the present invention relates to methods for treating subterranean formations. More particularly, the present invention relates to drilling, completion, or workover fluids that comprise nonionic cellulose ether polymers and their use in subterranean applications.
  • a method comprising : providing a drilling fluid, completion fluid, or workover fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer having hydroxyethyl groups and being further substituted with one or more hydrophobic substituents, wherein the cellulose ether has at least one of the following properties (a), (b) or (c):
  • a storage modulus of at least 15 Pascals at 25°C and a retained storage modulus, %G ' 8 o/25, of at least 12 percent, wherein %G ' 8 o/2s [storage modulus at 80°C / storage modulus at 25°C] ⁇ 100, the storage modulus at 25°C and 80°C being measured as a 1 % aqueous solution;
  • the method comprises: providing a drilling fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer having hydroxyethyl groups and being further substituted with one or more hydrophobic substituents, wherein the cellulose ether has at least one of the following properties (a), (b) or (c):
  • %n.8o/25 [dynamic solution viscosity at 80°C / dynamic solution viscosity at 25°C] x 100, the dynamic solution viscosity at 25°C and 80°C being measured as 1 % aqueous solution;
  • a storage modulus of at least 15 Pascals at 25°C and a retained storage modulus, %G ' 8 o/2s, of at least 12 percent, wherein %G ' 8 o/2s [storage modulus at 80°C / storage modulus at 25°C] ⁇ 100, the storage modulus at 25°C and 80°C being measured as a 1 % aqueous solution;
  • the method may comprise the step of placing the drilling fluid, completion fluid, or workover fluid in the subterranean formation is part of a subterranean operation selected from the group consisting of an underbalanced drilling operation, an overbalanced drilling operation, and a completion operation.
  • the subterranean formation may comprise a bottom hole temperature of up to and including about 275 °F (135 °C).
  • the subterranean formation comprises a bottom hole temperature of 200 °F (93 °C) or more and/or a pressure of at least 5,000 psi.
  • the aqueous base fluid of the present invention may be selected from the group consisting of fresh water, salt water, brine, seawater, and any combinations thereof.
  • the nonionic cellulose ether may be present in the drilling fluid, completion fluid, or workover fluid in an amount in the range of about 0.01% to about 15% by weight of the drilling fluid, completion fluid, or workover fluid.
  • the nonionic cellulose ether polymer has a molecular weight in the range of from about 500,000 to 10,000,000.
  • the nonionic cellulose ether polymer is crosslinked with a metal ion.
  • the drilling fluid, completion fluid, or workover fluid of the present invention may maintain thermal stability and gel strength at temperatures up to about 350 °F (177 °C).
  • the nonionic cellulose ether polymer according of the present invention may maintain the structure in a stress range exceeding about 12 Pa.
  • the nonionic cellulose ether polymer is modified by the addition of a hydrocarbon group having from about 1 to about 22 carbon atoms.
  • the hydrocarbon group may be selected from the group consisting of a linear alkyl, a branched alkyl, an alkenyl, an aryl, an alkylaryl, an arylalkyl, a cycloalkyl, and a mixture thereof.
  • the drilling fluid, completion fluid, or workover fluid comprises additional additives selected from the group consisting of a defoamer, a surfactant, a crosslinking agent, a proppant particulate, a gravel particulate, a pH-adjusting agent, a pH buffer, a breaker, a delinker, a catalyst, and combinations thereof.
  • additional additives selected from the group consisting of a defoamer, a surfactant, a crosslinking agent, a proppant particulate, a gravel particulate, a pH-adjusting agent, a pH buffer, a breaker, a delinker, a catalyst, and combinations thereof.
  • the fluid provided is a drilling fluid and the step of placing the drilling fluid may comprises the step of drilling a well bore in a formation in an operation comprising the drilling fluid.
  • a drilling fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer having hydroxyethyl groups and being further substituted with one or more hydrophobic substituents, wherein the cellulose ether has at least one of the properties (a), (b) or (c):
  • %n.8o/25 [dynamic solution viscosity at 80°C / dynamic solution viscosity at 25°C] x 100, the dynamic solution viscosity at 25°C and 80°C being measured as 1 % aqueous solution;
  • a storage modulus of at least 15 Pascals at 25°C and a retained storage modulus, %G ' 80 /25, of at least 12%, wherein ° oG ' 8 o,25 [storage modulus at 80°C / storage modulus at 25°C] ⁇ 100, the storage modulus at 25°C and 80°C being measured as a 1 % aqueous solution;
  • the drilling fluid is placed in the subterranean formation as part of a subterranean operation selected from the group consisting of an underbalanced drilling operation, and an overbalanced drilling operation.
  • the drilling fluid may comprise a hydrophobically modified hydroxyethylcellose in an amount in the range of about 0.01% to about 15% by weight of the drilling fluid.
  • the drilling fluid be able to maintain thermal stability and gel strength at temperatures up to about 350°F (177°C).
  • Figure 1 is a graphical representation of the rheological performance of a fluid containing nonionic cellulose ether polymer in various brines.
  • Figures 2A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer versus various other viscosifying agents in 10 ppg of NaBr.
  • Figures 3A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer versus various other viscosifying agents in 10 ppg of NaBr post hot-roll at 220°F (104 °C).
  • Figures 4A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer versus various other viscosifying agents in 13.5 ppg of CaBr 2 .
  • Figures 5A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer versus various other viscosifying agents in lOppg of CaBr 2 post hot-roll at 220°F (104 °C).
  • Figures 6A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer versus various other viscosifying agents in 15.5 ppg Ca/ZnBr 2 .
  • Figures 7A-B show the temperature profiles for the nonionic cellulose ether polymer versus various other viscosifying agents.
  • Figures 8A-B are graphical representations of the rheological performance of a fluid containing nonionic cellulose ether polymer and a defoamer.
  • Figure 9 depicts the dynamic rheological studies performed to evaluate the storage (C) and loss (G”) moduli of nonionic cellulose ether polymer versus Xanthan and unmodified hydroxyethylcellulose.
  • Figure 10 depicts an evaluation of thermal stability via temperature cycling to simulate drilling conditions for the nonionic cellulose ether polymer.
  • Figure 11 is a graphical representation of the breakdown of nonionic cellulose ether polymer in the presence of heat and acid.
  • the present invention relates to methods for treating subterranean formations. More particularly, , the present invention relates to drilling, completion, or workover fluids that comprise nonionic cellulose ether polymers and their use in subterranean applications.
  • nonionic cellulose ether polymers used in the drilling, completion, or workover fluids of the present invention may provide better solubility of the polymer and have greater thermal stability as compared to other fluids, while maintaining the removal capabilities of traditional unmodified hydroxyethylcellulose in drilling, completion, or workover operations.
  • the drilling, completion, or workover fluids may have greater gel strength during the operations, but require relatively quick removal of the gels.
  • the nonionic cellulose ether polymers of the present invention may exhibit excellent suspension capabilities above conventional unmodified hydroxyethylcellulose.
  • Another potential advantage of the methods of the present invention is that they may allow use in subterranean formations where complete removal of gels is needed by acid degradation.
  • Another potential advantage of the methods of the present invention is the increased suspension of the nonionic cellulose ether polymer in a drilling, completion, or workover fluid.
  • the increased suspension of the nonionic cellulose ether polymer in a drilling, completion, or workover fluid may lead to better thermal stability that in turn, is believed to aid in clay inhibition, especially in drilling, completion, and workover operations.
  • Drilling, completion, and workover fluids comprising a nonionic cellulose ether polymer described herein may have increased viscosity efficiency when compared to other commonly used polymeric viscosifying agents in such operations.
  • the aqueous base fluid utilized in the drilling, completion, and workover fluids according to the present invention may be fresh water, salt water (e.g., water containing one or more salts dissolved therein), brine (e.g., saturated salt water), seawater, and any combinations thereof.
  • the brines may contain substantially any suitable salts, including, but not necessarily limited to, salts based on metals, such as, calcium, magnesium, sodium, potassium, cesium, zinc, aluminum, and lithium. Salts of calcium and zinc are preferred.
  • the salts may contain substantially any anions, with preferred anions being less expensive anions including, but not necessarily limited to chlorides, bromides, formates, acetates, and nitrates.
  • the choice of brine may increase the associative properties of the nonionic cellulose ether polymer in the drilling, completion, or workover fluid.
  • a person of ordinary skill in the art, with the benefit of this disclosure, will recognize the type of brine and ion concentration needed in a particular application of the present invention depending on, among other factors, the other components of the drilling, completion, and workover fluids, the desired associative properties of such fluids, and the like.
  • the aqueous base fluid may be from any source, provided that it does not contain an excess of compounds that may adversely affect other components in the drilling, completion, or workover fluid.
  • the aqueous base fluid may be present in the drilling, completion, or workover fluids in an amount in the range of about 20% to about 99% by weight of the drilling, completion, or workover fluid.
  • the base fluid may be present in the drilling, completion, or workover fluids in an amount in the range of about 20% to about 80% by weight of the drilling, completion, or workover fluid.
  • Suitable nonionic cellulose ethers are substituted with one or more hydrophobic substituents, preferably with acyclic or cyclic, saturated or unsaturated, branched or linear hydrocarbon groups, such as an alkyl, alkylaryl or arylalkyl group having at least 8 carbon atoms, generally from 8 to 32 carbon atoms, preferably from 10 to 30 carbon atoms, more preferably from 12 to 24 carbon atoms, and most preferably from 12 to 18 carbon atoms.
  • arylalkyl group and “alkylaryl group” mean groups containing both aromatic and aliphatic structures.
  • the most preferred aliphatic hydrophobic substituent is the hexadecyl group, which is most preferably straight-chained.
  • the hydrophobic substituent is non-ionic.
  • Suitable nonionic cellulose ethers preferably have a weight average molecular weight of at least 1,000,000, more preferably at least 1,300,000. Their weight average molecular weight is preferably up to 2,500,000, more preferably up to 2,000,000.
  • Suitable nonionic cellulose ethers preferably have a Brookfield viscosity of at least 5000 mPa-sec, more preferably at least 6000 mPa-sec, and even more preferably at least 9000 mPa-sec.
  • the nonionic cellulose ethers preferably have a Brookfield viscosity of up to 20,000 mPa-sec, more preferably up to 18,000 mPa-sec, and most preferably up to 16,000 mPa-sec.
  • the Brookfield viscosity is measured as 1% aqueous solution at 30 rpm, spindle #4 at 25.0°C on a Brookfield viscometer. The Brookfield viscosity is dependent on the hydrophobe substitution, but is also an indication of the molecular weight of the nonionic cellulose ether.
  • Suitable nonionic cellulose ethers have at least one of the properties further described below:
  • % ⁇ 8 ⁇ /25 [dynamic solution viscosity at 80°C / dynamic solution viscosity at 25°C] x 100, the dynamic solution viscosity at 25°C and 80°C being measured as 1 % aqueous solution;
  • a storage modulus of at least 15 Pascals at 25°C and a retained storage modulus, °/oG ' 8 o 2 5, of at least 12 percent, wherein %G ' 8 o/25 [storage modulus at 80°C / storage modulus at 25°C] ⁇ 100, the storage modulus at 25°C and 80°C being measured as a 1 % aqueous solution; and
  • the nonionic cellulose ether may comprise two of the properties (a), (b) and (c) in combination. Alternatively, the nonionic cellulose ether has all three properties (a), (b) and (c) in combination. [0046] A description of suitable nonionic cellulose ether polymers is in U.S. Provisional Patent Application Serial No. 61/373,436, which is hereby incorporated by reference.
  • the nonionic cellulose ether polymer should be added to the aqueous base fluid in an amount sufficient to form the desired drilling fluid, completion fluid, or workover fluid.
  • the nonionic cellulose ether polymer may be present in an amount of about 0.01% to about 15% by weight of the drilling, completion, or workover fluid.
  • the nonionic cellulose ether polymer may be present in an amount of about 0.1% to about 10% by weight of the drilling, completion, or workover fluid.
  • the nonionic cellulose ether polymers may have increased thermal stability when in the presence of brine versus water.
  • the increase in thermal stability may be attributed to the minimization of the hydrolytic attack due to decreased free water in the drilling, completion, or workover fluid. It is believed that the increase in thermal stability in aqueous base fluid may be due to changing the contact of the aqueous media with the backbone of the polymer chains, facilitating the protection of the acetal linkage (e.g., 1,4-glycocidic linkage) of the backbone.
  • the acetal linkage is thought to be generally unprotected in unmodified hydroxyethylcellulose polymers.
  • Nonionic cellulose ether polymer may be used to increase the viscosity of drilling fluid, completion fluid, or workover fluid.
  • the nonionic cellulose ether polymer may increase the viscosity of such fluids, for example, by associative interactions between hydrophobic groups of the nonionic cellulose ether polymer to form intermolecular micellar bonds, which result in a three-dimensional network.
  • the nonionic cellulose ether polymers may result in a three-dimensional network able to maintain structure over a broader stress range, especially as compared to other biopolymers that have not been similarly modified.
  • the nonionic cellulose ether polymer may maintain structure in a stress range exceeding about 12 Pa.
  • Additional additives may be added to the drilling, completion, or workover fluids as deemed appropriate for a particular application by one skilled in the art, with the benefit of this disclosure.
  • additives include, but are not limited to, weighting agents, biocides, corrosion inhibitors, gel stabilizers, surfactants, scale inhibitors, antifoaming agents, foaming agents, fluid loss control additives, shale swelling inhibitors, radioactive tracers, defoamers, surfactants, crosslinking agents, particulates, pH-adjusting agents, pH buffers, salts, breakers, delinkers, weighting agents, corrosion inhibitors, combinations thereof, and the like, and numerous other additives suitable for use in subterranean operations.
  • Surfactants may be used to facilitate the formation of micellar bonds in a drilling fluid, completion fluid, or workover fluid. It is believed that the hydrophobic groups of the nonionic cellulose ether polymer may become incorporated into surfactant micelles, which are believed to act as crosslinkers for the polymer, creating structure and strength. These surfactants may show Newtonian or viscoelastic behavior when present in water by themselves in concentrations of less than 20%.
  • the surfactant may be a non-viscoelastic surfactant. Suitable surfactants may be anionic, neutral, cationic or zwitterionic. Aqueous liquids containing the surfactants may respond to shear with a Newtonian or viscoelastic behavior.
  • anionic surfactants with Newtonian rheological behavior are preferred.
  • suitable anionic surfactants include, but are not limited to, sodium decylsulfate, sodium lauryl sulfate, alpha olefin sulfonate, alkylether sulfates, alkyl phosphonates, alkane sulfonates, fatty acid salts, arylsulfonic acid salts, and combinations thereof.
  • Suitable cationic surfactants include, but are not limited to, trimethylcocoammonium chloride, trimethyltallowammonium chloride, dimethyldicocoammonium chloride, bis(2-hydroxyethyl)tallow amine, bis(2-hydroxyethyl)erucylamine, bis(2-hydroxyethyl)coco-amine, cetylpyridinium chloride, and combinations thereof.
  • the surfactant may be included in the drilling, completion, or workover fluid in an amount of about 0.1% to about 20% by weight of the drilling, completion, or workover fluid.
  • the formation of micelles in the fluid may negatively impact the overall fluid.
  • the nonionic cellulose ether polymer may be crosslinked by any suitable crosslinking agent or method.
  • a crosslinking agent may be utilized to crosslink the nonionic cellulose ether polymer to form the crosslinked viscosifying agent.
  • the drilling, completion, or workover fluids of the present invention may be formed by contacting an aqueous base fluid comprising nonionic cellulose ether polymers with a crosslinking agent, and allowing a crosslinked viscosifying agent to form.
  • crosslinking agents are suitable for use in the present invention.
  • the nonionic cellulose ether polymer When used, the nonionic cellulose ether polymer will be referred to herein as being "crosslinked with a metal ion.”
  • suitable crosslinking agents include, but are not limited to, borate releasing compounds and compounds that release transition metal ions when dissolved in an aqueous liquid.
  • Suitable borate releasing compounds include, but are not limited to, boric acid, disodium octaborate tetrahydrate, sodium diborate, ulexite, and colemanite.
  • An example of a suitable borate releasing compound is commercially available under the trade name "HMPTM Link” crosslinker from Halliburton Energy Services, Duncan, Oklahoma.
  • Suitable borate releasing compound is commercially available under the trade name "CL-38TM" delayed borate crosslinker from Halliburton Energy Services, Duncan, Oklahoma.
  • Suitable compounds that release transition metal ions include, but are not limited to, compounds capable of supplying zirconium ions such as, for example, zirconium lactate, zirconium lactate triethanolamine, zirconium carbonate, zirconium acetylacetonate, and zirconium diisopropylamine lactate; compounds capable of supplying titanium ions such as, for example, titanium ammonium lactate, titanium triethanolamine, titanium acetylacetonate; aluminum compounds such as, for example, aluminum lactate or aluminum citrate; compounds capable of supplying iron ions, such as, for example, ferric chloride; compounds capable of supplying chromium ion such as, for example, chromium III citrate; or compounds capable of supplying antimony ions.
  • the crosslinking agent may be added to the aqueous base fluid comprising nonionic cellulose ether polymer in an amount sufficient, inter alia, to provide the desired degree of crosslinking.
  • the drilling, completion, or workover fluids optionally may comprise a pH buffer.
  • the pH buffer may be included in the drilling, completion, or workover fluids to maintain pH in a desired range, inter alia, to enhance the stability of the drilling, completion, or workover fluid.
  • suitable pH buffers include, but are not limited to, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium or potassium diacetate, sodium or potassium phosphate, sodium or potassium hydrogen phosphate, sodium or potassium dihydrogen phosphate, sodium borate, sodium or ammonium diacetate, sulfamic acid, and the like.
  • the pH buffer may be present in a drilling, completion, or workover fluid in an amount sufficient to maintain the pH of the drilling, completion, or workover fluid at a desired level.
  • One of ordinary skill in the art, with the benefit of this disclosure, will recognize the appropriate pH buffer and amount of pH buffer to use for a chosen application.
  • the drilling, completion, or workover fluids further may include pH-adjusting compounds for adjusting the pH of the drilling, completion, or workover fluid, inter alia, to a desired pH for crosslinking and/or enhance hydration of the nonionic cellulose ether polymer.
  • pH-adjusting compounds include any pH-adjusting compound that does not adversely react with the other components of the drilling, completion, or workover fluid.
  • pH-adjusting compounds include, but are not limited to, sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, fumaric acid, formic acid, acetic acid, acetic anhydride, hydrochloric acid, hydrofluoric acid, hydroxyfluoboric acid, polyaspartic acid, polysuccinimide, ammonium diacetate, sodium diacetate, and sulfamic acid.
  • the appropriate pH-adjusting compound and amount thereof may depend upon the formation characteristics and conditions, and other factors known to individuals skilled in the art with the benefit of this disclosure.
  • the pH of the drilling, completion, or workover fluids should be adjusted to above about 8 to about 12 to facilitate the crosslink of the nonionic cellulose ether polymer.
  • Those skilled in the art, with the benefit of this disclosure, will be able to adjust the pH range in the viscosified aqueous fluids as desired.
  • the drilling, completion, or workover fluid after the drilling, completion, or workover fluid has performed its desired function, its viscosity may be reduced.
  • the drilling, completion, or workover fluid may be flowed back to the surface, and the well may be returned to production .
  • the viscosity of the drilling, completion, or workover fluids may be reduced by a variety of means. Breakers capable of reducing the viscosity of the drilling, completion, or workover fluids at a desired time may be included in the drilling, completion, or workover fluid to reduce the viscosity thereof.
  • Delinkers capable of lowering the pH of the drilling, completion, or workover fluids at a desired time may be included in the drilling, completion, or workover fluid to reduce the viscosity thereof. Such delinkers may be especially useful when the nonionic cellulose ether polymer has been crosslinked with a metal ion.
  • the drilling, completion, or workover fluids of the present invention may further comprise a breaker.
  • a breaker that is able to reduce the viscosity of the drilling, completion, or workover fluids when desired is suitable for use in the methods of the present invention.
  • delayed gel breakers that will react with the drilling, completion, or workover fluids after desired delay periods may be used. Suitable delayed gel breakers may be materials that are slowly soluble in a drilling, completion, or workover fluid.
  • Suitable delayed breakers include, but are not limited to, enzyme breakers, such as alpha and beta amylases, amyloglucosidase, invertase, maltase, cellulase, and hemicellulase; acids, such as maleic acid and oxalic acid; and oxidizing agents, such as sodium chlorite, sodium bromate, sodium persulfate, ammonium persulfate, magnesium peroxide, lactose, ammonium sulfate, and triethanol amine.
  • enzyme breakers such as alpha and beta amylases, amyloglucosidase, invertase, maltase, cellulase, and hemicellulase
  • acids such as maleic acid and oxalic acid
  • oxidizing agents such as sodium chlorite, sodium bromate, sodium persulfate, ammonium persulfate, magnesium peroxide, lactose, ammonium
  • these delayed breakers can be encapsulated with slowly water-soluble or other suitable encapsulating materials.
  • water-soluble and other similar encapsulating materials include, but are not limited to, porous solid materials such as precipitated silica, elastomers, polyvinylidene chloride (PVDC), nylon, waxes, polyurethanes, polyesters, cross-linked partially hydrolyzed acrylics, other polymeric materials, and the like.
  • the appropriate breaker and amount thereof may depend upon the formation characteristics and conditions, the pH of the drilling, completion, or workover fluid, and other factors known to individuals skilled in the art with the benefit of this disclosure.
  • the breaker may be included in a drilling, completion, or workover fluid in an amount in the range of from about 0.1 gallons to about 100 gallons per 1000 gallons of the aqueous base fluid.
  • breakers may be especially useful when the nonionic cellulose ether polymer has been crosslinked with a metal ion.
  • the drilling, completion, or workover fluids may comprise a delinker that is capable of lowering the pH of the drilling, completion, or workover fluid at a desired time causing the crosslinks of the viscosifying agent to reverse.
  • a delinker capable of lowering the pH of the drilling, completion, or workover fluid at a desired time causing the crosslinks of the viscosifying agent to reverse.
  • the crosslinks may be reversed (or delinked) by lowering the pH of the drilling, completion, or workover fluid to below about 8.
  • the delinker may comprise encapsulated pH-adjusting agents or acid-releasing degradable materials capable of reacting over time in an aqueous environment to produce an acid.
  • Suitable pH-adjusting agents include, but are not limited to, fumaric acid, formic acid, acetic acid, acetic anhydride, hydrochloric acid, hydrofluoric acid, hydroxyfluoboric acid, polyaspartic acid, polysuccinimide, combinations thereof, and the like.
  • the pH-adjusting agents may be encapsulated using any suitable encapsulation technique. Exemplary encapsulation methodology is described in U.S. Patent Nos. 5,373,901 ; 6,444,316; 6,527,051; and 6,554,071, the relevant disclosures of which are incorporated herein by reference.
  • Acid-releasing degradable materials also may be included in the drilling, completion, or workover fluids to decrease the pH of the drilling, completion, or workover fluid.
  • Suitable acid-releasing degradable materials that may be used in conjunction with the present invention are those materials that are substantially water insoluble such that they degrade over time, rather than instantaneously, in an aqueous environment to produce an acid.
  • suitable acid-releasing degradable materials include orthoesters; poly(ortho esters); lactides; poly (lactides); glycolides; poly(glycolides); substituted lactides wherein the substituted group comprises hydrogen, alkyl, aryl, alkylaryl, acetyl heteroatoms and mixtures thereof; substantially water insoluble anhydrides; and poly(anhydrides).
  • the acid-releasing degradable material may provide a relatively fast break or a relatively slow break, depending on, for example, the particular acid-releasing degradable material chosen.
  • Materials suitable for use as an acid-releasing degradable material may be considered degradable if the degradation is due, inter alia, to chemical and/or radical processes, such as hydrolysis, oxidation, or enzymatic decomposition.
  • the inclusion of a particular delinker and amount thereof may depend upon the formation characteristics and conditions, the particular crosslinking agent, and other factors known to individuals skilled in the art with the benefit of this disclosure.
  • the delinker of the present invention may be included in a drilling, completion, or workover fluid in an amount in the range of from about 0.01 pounds to about 100 pounds per 1000 gallons of the single salt aqueous fluid.
  • the drilling, completion, or workover fluids optionally may comprise a catalyst.
  • a catalyst may be included in the drilling, completion, or workover fluids to activate the breaker dependent, inter alia, upon the pH of the drilling, completion, or workover fluid and formation conditions.
  • suitable catalysts include, but are not limited to, transition metal catalysts, such as copper and cobalt acetate.
  • An example of a suitable cobalt acetate catalyst is available under the trade name "CAT-OS-1" catalyst from Halliburton Energy Services, Duncan, Oklahoma.
  • the catalyst may be included in a drilling, completion, or workover fluid in an amount in the range of from about 0.01 pounds to about 50 pounds per 1000 gallons of the single salt aqueous fluid.
  • the drilling, completion, or workover fluids may be prepared by any suitable method.
  • the drilling, completion, or workover fluids of the present invention may be produced at the well site.
  • nonionic cellulose ether polymer may be combined with an aqueous base fluid.
  • additional additives as discussed above may be combined with the aqueous base fluid as desired.
  • a crosslinking agent as discussed above, may be added to the aqueous base fluid that comprises the nonionic cellulose ether polymer and other suitable additives.
  • a drilling, completion, or workover fluid concentrate may be prepared by combining an aqueous fluid (e.g. , water) and a nonionic cellulose ether polymer described herein.
  • aqueous fluid e.g. , water
  • a nonionic cellulose ether polymer described herein.
  • the water in the drilling, completion, or workover fluid concentrate may be fresh water or water containing a relatively small amount of a dissolved salt or salts.
  • the nonionic cellulose ether polymer may be present in the drilling, completion, or workover fluid concentrate in an amount in the range of from about 40 lbs to about 200 lbs per 1000 gallons of the aqueous fluid.
  • the nonionic cellulose ether polymer may be crosslinked with a metal ion.
  • drilling, completion, or workover fluids may be added to the drilling, completion, or workover fluid concentrate as desired.
  • the drilling, completion, or workover fluid concentrate may be prepared at an offsite manufacturing location and may be stored prior to use. Such methods may be preferred, for example, when these drilling, completion, or workover fluid concentrates are to be used in offshore applications, e.g., because the equipment and storage volumes may be reduced.
  • the aqueous base fluid described above, may be combined with the concentrate. When the concentrate is mixed with the aqueous base fluid, no hydration time may be required because the nonionic cellulose ether polymer may already be substantially fully hydrated.
  • aqueous base fluid may be combined with additional additives, discussed above.
  • a crosslinking agent as discussed above, may be added to the aqueous base fluid that comprises the nonionic cellulose ether polymer and other suitable additives.
  • the drilling, completion, or workover fluids of the present invention may be used in any of a variety of suitable applications.
  • the drilling, completion, or workover fluids may be used in subterranean operations, including, but not limited to, underbalanced drilling, overbalanced drilling, completion, and workover operations.
  • the drilling, completion, or workover fluids may be used in subterranean operations as drilling fluid additives, and the like.
  • An example method of the present invention generally may comprise providing a drilling, completion, or workover fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer; and introducing the drilling, completion, or workover fluid into the subterranean formation having a bottom hole temperature of about 275°F (135°C) or more or a pressure of 5000 psi or more.
  • the method further may comprise allowing the nonionic cellulose ether polymer to maintain thermal stability and gel strength at temperatures up to about 350°F (177°C).
  • the length of time for which thermal stability can be maintained will vary with temperature. For example, at the higher temperatures the gel may degrade at a faster rate.
  • the drilling, completion, or workover fluid may undergo acid hydrolysis of the nonionic cellulose ether polymer.
  • the ability to acid hydrolyze such drilling, completion, or workover fluids may be advantageous in numerous subterranean operations, such as to facilitate a reduction in viscosity of a fluid or to degrade a filter cake.
  • a drilling fluid that comprises a nonionic cellulose ether polymer as described herein may be circulated in a well bore while drilling.
  • the method may include forming a filter cake comprising the solid particle upon a surface. Fluid loss to the formation through the filter cake may be reduced.
  • the filter cake comprises the nonionic cellulose ether polymer, the filter cake may be easily removed in accordance with the present invention, in that the filter cake may be removed by acid degradation.
  • the filter cake formed by the drilling, completion, or workover fluids in accordance with the present invention may be easily removed by using an acidic solution, an operator nevertheless occasionally may elect to circulate a separate clean-up solution or breaker through the well bore under certain circumstances, to enhance the rate of degradation of the filter cake.
  • removal of the filter cake may be enhanced by contacting the filter cake with water.
  • An example of a method of the present invention comprises: placing a drill-in fluid in a subterranean formation, the drill-in fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer; and forming a filter cake comprising the nonionic cellulose ether polymer upon the surface within the formation whereby fluid loss through the filter cake is reduced.
  • the drilling, completion, or workover fluids of the present invention may be placed into the well bore as a pill in drilling, completion, or workover operations.
  • the drilling, completion, or workover fluids may be placed into the subterranean formation as a viscosified pill during an underbalanced drilling operation.
  • An underbalanced drilling operation may be referred to as a managed pressure drilling operation by some skilled in the art.
  • Influxes from the formation may be experienced during an underbalanced drilling operation. Nitrogen may be used to combat this.
  • the drilling, completion, or workover fluids may be recovered by pumping gas into the formation to lift the pill out of the subterranean formation. The treatment fluid is then replaced with drilling fluid.
  • Another example of a method of the present invention comprises using the drilling, completion, or workover fluids prior to a cementing operation, for example, as a completion fluid .
  • An example of such method may comprise a pre-treatment providing the drilling, completion, or workover fluid comprising an aqueous base fluid and a nonionic cellulose ether polymer; introducing these fluids into the subterranean formation before placing a cement composition into the formation.
  • the present invention preferably provides drilling, completion, or workover fluids that comprise a nonionic cellulose ether polymer that has been crosslinked with a metal ion.
  • drilling, completion, or workover fluids may be useful in a variety of subterranean applications, including, drilling, completion, or workover.
  • Brine testing was performed to determine the solubility of the nonionic cellulose ether polymer.
  • the following brines were tested: 10.0 ppg NaBr; 10.0 ppg NaCI; 10.0 ppg CaCI 2 brines were tested for performance before and after hot roll for the various certain polymers remain insoluble in these fluid.
  • Figure 1 depicts the rheological performance in various brines at 1 wt % polymer. It can be seen that the nonionic cellulose ether polymer provides excellent low shear viscosity response that thins off at high shear rates (i.e., thixotropic flow properties). It should be noted that the 15.5 ppg Ca/ZnBr 2 sample was actually gelled to the extent that it was not possible to achieve the correct reading due to the Weissenberg effect within the Anton Paar geometry. However, the indication of such elevated low shear viscosities was evidence of possible increased suspension capabilities versus traditional unmodified hydroxyethylcellulose.
  • a comparative analysis of other biopolymers was also performed, by comparing the properties of each biopolymer in each brine mentioned above by monitoring the capabilities of the nonionic cellulose ether polymer as to its rheological behavior (i.e., flow and suspension properties) and thermal stability.
  • FIGs 2A-B depict the comparative study of the various biopolymers in 10.0 ppg NaBr. All the chosen biopolymers were mixed as described above and allowed to equilibrate at 150 °F (66°C) for 4 h before testing.
  • the low shear viscosity of the nonionic cellulose ether polymer is comparable to the other biopolymers (particularly Xanthan) that are known to provide excellent suspension characteristics.
  • the hydrophobically modified polymer exhibits low shear viscosity values that are an order of magnitude higher (10X).
  • the experimental nonionic cellulose ether polymer does not thermally thin to the extent of unmodified hydroxyethylcellulose and provides viscosity comparable to Xanthan at 190 °F (88°C). It should be pointed out that the Diutan and Scleroglucan gums do not thermally thin to any extent within the tested temperature parameters as expected from their physicochemical properties.
  • FIGs 4A-B depict the comparative study of the various biopolymers in 13.5 ppg CaBr 2 .
  • the employment of divalent brines proved to be quite interesting.
  • the solubility of the various biopolymers in the 13.5 ppg CaBr 2 was limited as the Scleroglucan yielded only minimal viscosity response and Diutan would not disperse to any extent.
  • the nonionic cellulose ether polymer proved to be an excellent choice as it performed with superb rheological properties and nominal thermal thinning.
  • the nonionic cellulose ether polymer maintained its thixotropic nature as well as elevated low shear viscosity values.
  • these rheological characteristics are indicative of increased suspension properties when compared to traditional unmodified hydroxyethylcellulose and are a result of the hydrophobic associations due to the hydrophobic modifications.
  • FIGs 6A-B depict the comparative study of the various biopolymers in 15.5 ppg Ca/ZnBr 2 .
  • Nonionic cellulose ether polymer provided an excellent viscosity response when blended with the 15.5 ppg Ca/ZnBr 2 salt solution.
  • HEC also rendered excellent viscosity profiles but, in the case of both polymers, most of the response was manifested in the viscous component (i.e., loss modulus).
  • BARAB INE defoamer The effect of a defoamer (i.e., BARAB INE defoamer) was measured to assess the contamination stability (effect of defoamer, glycols, etc.) of the nonionic cellulose ether polymer in the drilling, completion, or workover fluids.
  • contamination stability effect of defoamer, glycols, etc.
  • BARABRINE Defoamer was the defoaming agent of choice for the examinations.
  • Figure 9 further shows that nonionic cellulose ether polymer demonstrated behavior that was similar to Xanthan in nature but superior in terms of performance.
  • the storage modulus was more than double the loss modulus.
  • Nonionic cellulose ether polymer was monitored to assay its ability to break down in the presence of acid and heat.
  • the same solution utilized in the previous section i.e., 1 wt % solution of nonionic cellulose ether polymer in 10.0 ppg NaBr
  • 9 M HCI to lower the pH to 3.0.
  • the solution was then placed in the FANN 50 viscometer and heated to 175 °F (79°C) at 100 rpms.
  • the viscosity of the solution had dramatically decreased as acid hydrolysis had chemically broken down the polymer.
  • compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of” or “consist of” the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values.

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Abstract

L'invention concerne un procédé comprenant : l'utilisation d'un fluide de forage, d'un fluide de complétion, ou d'un fluide de reconditionnement comprenant un fluide de base aqueux et un polymère d'éther de cellulose non ionique ayant des groupes hydroxyéthyle et étant en plus substitué avec un ou plusieurs substituants hydrophobes, et le placement du fluide de forage, du fluide de complétion, ou du fluide de reprise dans une formation souterraine.
PCT/GB2011/001750 2011-12-21 2011-12-21 Polymère cellulosique modifié pour l'amélioration des fluides de forage de puits WO2013093388A1 (fr)

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Application Number Priority Date Filing Date Title
PCT/GB2011/001750 WO2013093388A1 (fr) 2011-12-21 2011-12-21 Polymère cellulosique modifié pour l'amélioration des fluides de forage de puits
MX2013001747A MX2013001747A (es) 2011-12-21 2011-12-21 Polimero celulosico modificado para fluidos mejorados de perforacion de pozo.
EP11805561.5A EP2794808A1 (fr) 2011-12-21 2011-12-21 Polymère cellulosique modifié pour l'amélioration des fluides de forage de puits
EA201390289A EA201390289A8 (ru) 2011-12-21 2011-12-21 Модифицированный целлюлозный полимер для улучшенных буровых жидкостей
CA2807827A CA2807827A1 (fr) 2011-12-21 2011-12-21 Polymere cellulosique modifie pour fluides de puits de forage ameliores
AU2011379603A AU2011379603A1 (en) 2011-12-21 2011-12-21 Modified cellulosic polymer for improved well bore fluids

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US20190040307A1 (en) * 2016-05-10 2019-02-07 Halliburton Energy Services, Inc. Shear-thinning self-viscosifying system for hydraulic fracturing applications
CN114934737A (zh) * 2022-05-11 2022-08-23 上海甘田光学材料有限公司 一种光热双调节智能玻璃的制备方法

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US11697755B2 (en) 2020-07-14 2023-07-11 Aramco Services Company Degradable tags for depth correlation mud logging

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US5373901A (en) 1993-07-27 1994-12-20 Halliburton Company Encapsulated breakers and method for use in treating subterranean formations
US5407919A (en) * 1993-09-29 1995-04-18 Brode; George L. Double-substituted cationic cellulose ethers
US6444316B1 (en) 2000-05-05 2002-09-03 Halliburton Energy Services, Inc. Encapsulated chemicals for use in controlled time release applications and methods
WO2006088953A1 (fr) * 2005-02-17 2006-08-24 Hercules Incorporated Hydroxyethylcellulose non uniformement substituee, derives, procede de fabrication et utilisations associes
CN102140337A (zh) * 2011-01-04 2011-08-03 中国石油大学(华东) 一种疏水缔合羟乙基纤维素驱油剂

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US5373901A (en) 1993-07-27 1994-12-20 Halliburton Company Encapsulated breakers and method for use in treating subterranean formations
US5407919A (en) * 1993-09-29 1995-04-18 Brode; George L. Double-substituted cationic cellulose ethers
US6444316B1 (en) 2000-05-05 2002-09-03 Halliburton Energy Services, Inc. Encapsulated chemicals for use in controlled time release applications and methods
US6527051B1 (en) 2000-05-05 2003-03-04 Halliburton Energy Services, Inc. Encapsulated chemicals for use in controlled time release applications and methods
US6554071B1 (en) 2000-05-05 2003-04-29 Halliburton Energy Services, Inc. Encapsulated chemicals for use in controlled time release applications and methods
WO2006088953A1 (fr) * 2005-02-17 2006-08-24 Hercules Incorporated Hydroxyethylcellulose non uniformement substituee, derives, procede de fabrication et utilisations associes
CN102140337A (zh) * 2011-01-04 2011-08-03 中国石油大学(华东) 一种疏水缔合羟乙基纤维素驱油剂

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Publication number Priority date Publication date Assignee Title
US20190040307A1 (en) * 2016-05-10 2019-02-07 Halliburton Energy Services, Inc. Shear-thinning self-viscosifying system for hydraulic fracturing applications
CN114934737A (zh) * 2022-05-11 2022-08-23 上海甘田光学材料有限公司 一种光热双调节智能玻璃的制备方法
CN114934737B (zh) * 2022-05-11 2024-04-05 上海甘田光学材料有限公司 一种光热双调节智能玻璃的制备方法

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MX2013001747A (es) 2013-10-16
EP2794808A1 (fr) 2014-10-29
AU2011379603A1 (en) 2013-07-11
EA201390289A1 (ru) 2013-08-30
CA2807827A1 (fr) 2013-06-21

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