WO2010015639A1 - Agents de réticulation aziridines pour la fabrication de gels non aqueux et de billes de polymère pour des applications en champ pétrolifère - Google Patents

Agents de réticulation aziridines pour la fabrication de gels non aqueux et de billes de polymère pour des applications en champ pétrolifère Download PDF

Info

Publication number
WO2010015639A1
WO2010015639A1 PCT/EP2009/060117 EP2009060117W WO2010015639A1 WO 2010015639 A1 WO2010015639 A1 WO 2010015639A1 EP 2009060117 W EP2009060117 W EP 2009060117W WO 2010015639 A1 WO2010015639 A1 WO 2010015639A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil
crosslinking agent
aziridine crosslinking
soluble
gel
Prior art date
Application number
PCT/EP2009/060117
Other languages
English (en)
Inventor
David Antony Ballard
Original Assignee
M-I Drilling Fluids Uk Limited
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 M-I Drilling Fluids Uk Limited filed Critical M-I Drilling Fluids Uk Limited
Publication of WO2010015639A1 publication Critical patent/WO2010015639A1/fr

Links

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
    • C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
    • C09K8/502—Oil-based compositions
    • 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
    • C09K8/50—Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
    • C09K8/504—Compositions based on water or polar solvents
    • C09K8/506—Compositions based on water or polar solvents containing organic compounds
    • C09K8/508—Compositions based on water or polar solvents containing organic compounds macromolecular compounds
    • C09K8/512—Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents

Definitions

  • Embodiments disclosed herein relate generally to methods for treating a wellbore, and more particularly, to aziridine crosslinking agents for producing non-aqueous gels and polymer beads used in treating the wellbore.
  • a drilling fluid may act to remove drill cuttings from the bottom of the hole to the surface, to suspend cuttings and weighting material when circulation is interrupted, to control subsurface pressures, to maintain the integrity of the wellbore until the well section is cased and cemented, to isolate the fluids from the formation by providing sufficient hydrostatic pressure to prevent the ingress of formation fluids into the wellbore, to cool and lubricate the drill string and bit, and/or to maximize penetration rate.
  • a common problem encountered during drilling operations is "lost circulation,” characterized by loss of drilling mud into downhole formations that are fractured, highly permeable, porous, cavernous, or vugular.
  • the drilling fluids are either lost to the formation matrix or to voids in direct communication with the wellbore.
  • Lost circulation is undesirable from an economic standpoint because it requires one to continually replenish the wellbore with costly drilling fluid.
  • Lost circulation is also undesirable from an operational and safety standpoint because it can destabilize permeable formations and damage the pay zone, and in extreme cases it can result in a blowout of the hydrocarbon zone followed by a well fire.
  • Induced mud losses may also occur when the mud weight, required for well control and to maintain a stable wellbore, exceeds the fracture resistance of the formations.
  • a particularly challenging situation arises in depleted reservoirs, in which the drop in pore pressure weakens hydrocarbon-bearing rocks, but neighboring or inter- bedded low permeability rocks, such as shales, maintain their pore pressure. This can make the drilling of certain depleted zones impossible because the mud weight required to support the shale exceeds the fracture resistance of the sands and silts.
  • lost circulation treatments are attempted to plug or block the openings either naturally formed or induced by the drilling operation.
  • Such lost circulation treatments have included a variety of treatment materials, including polymeric based treatments having sufficient strength and integrity to minimize lost circulation into voids in direct communication with the wellbore, such as fractures, fracture networks, vugs, washouts, cavities, and the like.
  • such polymeric based treatments may also be suitable for strengthening weakly or unconsolidated formation as a preventative measure.
  • Formations of this type are formations which are, at least in part, consolidated by the presence of clays in the formation. Such clays can become dispersed and expanded by the production of aqueous fluids from the formation, thereby weakening the overall formation to the point where it becomes unconsolidated or weakly consolidated with the resulting production of particulates into the wellbore.
  • uncemented, weakly consolidated or unconsolidated formations impose limits on the draw-down pressure which can be used to produce fluids from the formation. This limits the rate at which fluids can be produced from the subterranean formation.
  • polymeric gel treatments have been used to consolidate or strengthen the formation.
  • gel treatments may also be used to reduce water production, i.e., water shut-off, through channeling in formation strata of relatively high permeabilities.
  • the treatments may be used to correct channeling or change the injection profile in water flooding.
  • one method to increase the production of a well is to perforate the well in a number of different locations, either in the same hydrocarbon bearing zone or in different hydrocarbon bearing zones, and thereby increase the flow of hydrocarbons into the well.
  • the problem associated with producing from a well in this manner relates to the control of the flow of fluids from the well and to the management of the reservoir.
  • the higher pressure zone may disembogue into the lower pressure zone rather than to the surface.
  • perforations near the "heel" of the well i.e., nearer the surface, may begin to produce water before those perforations near the "toe” of the well.
  • the production of water near the heel reduces the overall production from the well.
  • gels in particular, have found utility in preventing mud loss, stabilizing and strengthening the wellbore, and zone isolation and water shutoff treatments.
  • water-based and oil-based wellbore fluids are both used. Water-based wellbore fluids are generally used early in the drilling process. Later, oil- based wellbore fluids are substituted as the well gets deeper and reaches the limit of water-based wellbore fluids due to limitations such as lubricity and well bore stabilization.
  • the majority of gels employ water compatible gelling and crosslinking agents, as exemplified by U.S. Patent Application Publication No. 20060011343 and U.S. Patent Nos. 7,008,908 and 6,165,947, which are useful when using water-based wellbore fluids.
  • a dearth of methods using non-aqueous gels and polymer beads which are compatible with oil-based wellbore fluids.
  • embodiments disclosed herein relate to methods of treating earthen formations including injecting non-aqueous gel components comprising at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent in a nonaqueous solution; and allowing the non-aqueous gel components to react in the earthen formation.
  • embodiments disclosed herein relate to non-aqueous and polymer beads gels for use in downhole applications containing the reaction product of at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent, wherein the at least one oil soluble or oil dispersible monomer and the aziridine crosslinking agent are combined in a non-aqueous solution.
  • embodiments disclosed herein relate to processes of strengthening a wellbore including injecting at least one oil soluble or oil dispersible monomer into an earthen formation, injecting at least one aziridine crosslinking agent into the earthen formation, and allowing the at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent to react to form a non-aqueous gel.
  • embodiments disclosed herein relate to a method of treating an earthen formation that includes injecting polymer beads comprising the reaction product of at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent in a non-aqueous solution; and allowing the polymer beads to swell in the earthen formation.
  • embodiments disclosed herein relate to methods of treating earthen formations with polymeric gels formed from at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent.
  • Such gels may be formed downhole by injection and reaction of the components in the wellbore, or may be formed from the swelling of preformed polymer beads downhole comprising the reaction product of at least one oil soluble or oil dispersible monomer and at least one aziridine crosslinking agent.
  • the inventor has surprisingly found that oil soluble or oil dispersible monomers may be crosslinked with aziridine crosslinking agents in a non-aqueous solution to form non-aqueous gels or polymer beads suitable for use in treating earthen formations.
  • Gels are solid, jelly-like materials formed from colloidal solutions of crosslinked gelling agents.
  • the gel typically contains about 99 wt. % liquid which is immobilized by surface tension in a macromolecular network of fibers built from a small amount of crosslinked gelling agent present.
  • gelling agents such as crosslinkable oil soluble or oil dispersible monomers may be crosslinked by aziridine crosslinking agents in a non-aqueous solution to form a non-aqueous gel in some embodiments disclosed herein.
  • the resulting non-aqueous gel is a polymeric network consisting of interconnected macro molecules which expand in all three dimensions. By weight, gels are mostly liquid, yet they behave like solids.
  • gels may have unique properties such as thixotropy, where they become fluid when agitated, but resolidify when resting.
  • the crosslinkable oil soluble or oil dispersible monomers may be dissolved or dispersed in a non-aqueous fluid, and an aziridine crosslinking agent may be added to the non-aqueous fluid, reacting with the oil soluble or oil dispersible monomers to form a gel.
  • the non-aqueous gel may be used in downhole applications as a component of drilling mud and may be preformed and pumped downhole. Alternatively, the components may be introduced sequentially downhole forming the non-aqueous gel in situ.
  • preformed discrete polymer beads of oil-soluble or dispersable monomers crosslinked by aziridine crosslinking agents may be dispersed in a wellbore fluid and pumped downhole.
  • Such polymer beads may be formed from a suspension or emulsion of crosslinked polymers.
  • beads may also be formed by forming (on the surface) a polymer network, and cutting such network into smaller discrete beads (which may be optionally dehydrated prior pumping downhole).
  • the polymer beads may absorb water, and swell, and may therefore be considered super absorbent polymers.
  • crosslinkable oil soluble or oil dispersible monomers may be crosslinked by aziridine crosslinking agents in a non-aqueous solution to form discrete soft elastic beads in some embodiments disclosed herein.
  • the resulting polymer bead is a crosslinked polymeric network consisting of interconnected macromolecules which expand in all three dimensions.
  • the crosslinkable oil soluble or oil dispersible monomers may be dissolved or dispersed in a non-aqueous fluid, and an aziridine crosslinking agent may be added to the non-aqueous fluid, reacting with the oil soluble or oil dispersible monomers to form a polymer beads.
  • the polymer beads may be used in downhole applications as a component of drilling mud and may be preformed and pumped downhole. Alternatively, the components may be introduced sequentially downhole forming the polymer beads in situ.
  • Polymer beads provide the advantage of being removable, if necessary, from the flow paths connecting a wellbore to the production zone of a penetrated formation. Further, polymer beads produced in situ may be used for various applications such as lost circulation, water shutoff treatment, or other uses in subterranean wells.
  • the non-aqueous gel may be formed from an oil soluble or oil dispersible monomer which is capable of being chemically crosslinked to form a polymeric structure.
  • oil soluble or oil dispersible monomers may have two or more functional groups possessing abstractable or "active" hydrogens.
  • Monomers having two or more functional groups possessing active hydrogens may crosslink to effectively form a gel network.
  • the oil soluble or oil dispersible monomer may possess carboxyl functional groups, primary or secondary amine functional groups, primary or secondary amide functional groups, alcohol functional groups, imine functional groups or derivatives thereof.
  • suitable oil soluble or oil dispersible monomers may comprise various synthetic compounds such as carboxylic acids, acrylates, urethanes, and oligomers and polymers thereof.
  • the oil soluble or oil dispersible monomer may be an oil soluble dimer acid, such as those commercially available under the trade name UNIDYME® from Arizona Chemical (Jacksonville, FL).
  • the oil soluble or oil dispersible monomer may be a low molecular weight acrylate -based polymer, such as those commercially available under the trade name EMI 759 from M-I SWACO (Houston, TX).
  • suitable oil soluble or oil dispersible monomers may comprise various natural oils such as soybean oil, linseed oil, rapeseed oil, cashew nut shell oil, perilla oil, tung oil, oiticia oil, safflower oil, poppy oil, hemp oil, cottonseed oil, sunflower oil, high-oleic triglycerides, triglycerides of euphorbia plants, peanut oil, olive oil, olive kernel oil, almond oil, kapok oil, hazelnut oil, apricot kernel oil, beechnut oil, lupin oil, maize oil, sesame oil, grapeseed oil, lallemantia oil, castor oil, herring oil, sardine oil, menhaden oil, whale oil, tall oil, and derivatives thereof.
  • natural oils such as soybean oil, linseed oil, rapeseed oil, cashew nut shell oil, perilla oil, tung oil, oiticia oil, safflower oil, poppy
  • the suitable oil soluble or oil dispersible monomers may comprise natural polymers and oligomers, such as starch, carboxymethylcellulose, guar, and derivatives thereof, as well as synthetic prepolymers such as polyurethanes.
  • An oil soluble or oil dispersible monomer containing a functional group with an active hydrogen may serve as the reactive nucleophile for crosslinking with an appropriate electrophile, such as an aziridine group.
  • the aziridine group reacts with the active hydrogen of the functional groups of the oil soluble or oil dispersible monomer.
  • Each aziridine group can react with an active hydrogen.
  • Multifunctional aziridine crosslinking agents may thereby crosslink oil soluble or oil dispersible monomers to form the non-aqueous gels of the present disclosure.
  • This reaction protonates and opens the aziridine ring, which then reacts with the nucleophile of the oil soluble or oil dispersible monomer to form a crosslinked network.
  • the mechanism of reaction for a carboxylic acid containing monomer is represented below.
  • R represents an oil soluble or oil dispersible group and may comprise a plurality of carboxyl groups for crosslinking
  • R' represents part of the aziridine crosslinking agent and may comprise aliphatic, aromatic or cycloaliphatic groups.
  • an oil soluble or oil dispersible monomer may be desirable when used in conjunction with an oil-based mud (OBM).
  • OBM oil-based mud
  • the oil soluble or oil dispersible character may lend solubility to the resultant monomer in the OBM.
  • One of ordinary skill in the art would recognize that the appropriate choice of oil soluble or oil dispersible monomer would depend on the desired properties of the end product gel. Traits that may be of interest in selecting a oil soluble or oil dispersible monomer may include gellation times at various temperatures, and the gel properties, such as gel strength, as inferred and defined by its resistance to tensile, compressive and impact forces, flexibility, rigidity, adhesion, chemical and heat tolerance.
  • Aziridine crosslinking agents are a group of organic compounds which contain the 2-methylaziridine functional group.
  • the 2-methylaziridine functional group has a molecular formula of C 2 H 5 N, and is a three-membered heterocycle containing one amine group and two methylene groups.
  • Aziridine compounds function as excellent crosslinking agents due to the extreme ring strain observed in this molecule.
  • the structure of the aziridine functional group is represented below.
  • the R group represents the rest of the aziridine compound, and may be any of H, an aliphatic group, an aromatic group, or a cycloaliphatic group.
  • Aziridine compounds may be used as crosslinkers in embodiments disclosed herein, and may be capable of being emulsified. These aziridine crosslinking agents may be bifunctional, trifunctional, or polyfunctional, having two, three, or n aziridine functional groups per molecule, as represented by the structures below.
  • the R, R 1 , and R 2 groups represent the rest of the aziridine compound, and may the same or different from each other.
  • the R groups may be any of an aliphatic group, an aromatic group, or a cycloaliphatic group.
  • the class of aziridine crosslinking agents useful herein is extremely broad, ranging from simple compounds to very complex compounds. Some examples of aziridine crosslinking agents useful in embodiments disclosed herein are represented below.
  • BPA N, N'-Bis-propylenadipic acid amide
  • the aziridine crosslinking agent may an aromatic aziridine such as N,N'-(methylenedi-p-phenylene)bis(aziridine-l -carboxamide), which is an bifunctional aromatic aziridine crosslinking agent and is commercially available under the trade name ICAPLINK X5 from ICAP-SIRA Chemicals and Polymers (Italy).
  • the aziridine crosslinking agent may be an aliphatic aziridine crosslinking agent such as trimethylolpropane-tris( ⁇ -(N-aziridinyl)propionate), which is an trifunctional aliphatic azirine and is commercially available under the trade name CORIAL® from BASF (Germany).
  • the aziridine crosslinking agent may be a polyfunctional aliphatic aziridine crosslinking agent having the molecular formula C 20 H 33 O 7 N 3 , which is commercially available under the trade name X AM A® 7 from Ichemco (Italy).
  • the oil soluble or oil dispersible monomers and/or the aziridine crosslinking agents may be used in their neat form, may be dissolved in a solvent, or may be dispersed or emulsified in a non-miscible phase, to form a nonaqueous gel.
  • the oil soluble or oil dispersible monomers and/or the aziridine crosslinking agents may be used in their neat form, may be dissolved in a solvent, or may be dispersed or emulsified in a non-miscible phase, to form elastic beads.
  • a gel or bead may be formed by mixing the oil soluble or oil dispersible monomers with the aziridine crosslinking agent in an appropriate solvent.
  • Solvents that may be appropriate may comprise oil-based muds for use in downhole applications and may include mineral oil, diesel, and synthetic oils.
  • the aziridine crosslinking agents and/or the oil soluble or oil dispersible monomers may be emulsified in a non-miscible phase.
  • emulsification of the aziridine crosslinking agent and/or the oil soluble or oil dispersible monomers in a non-miscible solvent may allow for optimal dispersion of the aziridine crosslinking agent.
  • Optimal dispersion of the aziridine crosslinking agent may promote the formation of a fairly uniform non-aqueous gel or bead.
  • a uniform gel or bead structure is desirable, in part because it allows greater predictability of gel or bead properties such as hardness, flexibility, and strength.
  • the aziridine crosslinking agent may be emulsified in the solvent, and the emulsion stabilized by the monomer.
  • aziridine crosslinking agent selected as the crosslinking agent will affect the properties of the resulting nonaqueous gel or bead.
  • selection of a polyfunctional aziridine crosslinking agent may affect the extent of crosslinking achieved.
  • selection of a trifunctional aziridine crosslinking agent may result in a denser non-aqueous gel or bead as compared to a non-aqueous gel or bead comprising a bifunctional aziridine crosslinking agent.
  • the molar equivalent ratio of the oil soluble or oil dispersible monomer (LM) to the selected aziridine crosslinking agent (ACA) will also affect the extent of crosslinking achieved.
  • LM: ACA oil soluble or oil dispersible monomer
  • ACA aziridine crosslinking agent
  • the LM:ACA ratio may be selected for low crosslinking that may lead to more flexible gel or bead structures.
  • the LM:ACA ratio may be selected for higher crosslinking that may lead to harder gel or bead structures.
  • the optimal ratios for the oil soluble or oil dispersible monomer and aziridine crosslinking agents may vary depending on the exact structures and desired properties of the gel or bead.
  • the weight ratio of oil soluble or oil dispersible monomer to aziridine crosslinking agent may vary from a range of about 35: 1 to about 5:1 , and from about 2: 1 to 1 : 1.5, and from about 1.2: 1 to 1 : 1.2.
  • the amount of aziridine crosslinking agent may affect the hardness of the resulting gel or bead. For example, in some embodiments, for a constant weight of oil soluble or oil dispersible monomer, increasing the amount of aziridine crosslinking agent may result in higher crosslinking density, and therefore a harder gel or bead.
  • the optimal volume of the aziridine crosslinking agent relative to the total volume of the gel or bead may vary depending upon the desired properties of the gel or bead.
  • the volume percent of the aziridine crosslinking agent relative to the total volume of the gel or bead comprises approximately 10 to 40 percent by volume.
  • the volume percent of the aziridine crosslinking agent relative to the total volume of the gel or bead is approximately 15 to 30 percent by volume.
  • the aziridine crosslinking agent may be modified to control the rate of crosslinking.
  • the aziridine crosslinking agent may be immobilized on an inert support.
  • the aziridine crosslinking agent may be encapsulated by a material that may retard that rate of reaction. Removal of this encapsulation at the desired time may be achieved by any means known in the art, for example chemical removal. The timing of the crosslinking reaction may therefore be controlled by such modifications.
  • the oil soluble or oil dispersible monomer and the aziridine crosslinking agent may be reacted at a temperature from -50 to 300 0 C. In other embodiments, the oil soluble or oil dispersible monomer and the crosslinking agent may be reacted at a temperature from 25 to 250 0 C; from 50 to 150 0 C in other embodiments; and from 60 to 100 0 C in yet other embodiments. In certain embodiments, the reaction temperature determines the amount of time required for gel or bead formation.
  • Embodiments of the gels or beads disclosed herein may be formed by mixing a oil soluble or oil dispersible monomer with an aziridine crosslinking agent.
  • a gel or beads may form immediately upon mixing the oil soluble or oil dispersible monomer and the aziridine crosslinking agent.
  • a gel or beads may form within 1 minute of mixing; within 5 minutes of mixing in other embodiments; within 30 minutes of mixing in other embodiments.
  • a gel or beads may form within 1 hour of mixing; within 8 hours in other embodiments; within 16 hours in other embodiments; within 80 hours in other embodiments; within 120 hours in yet other embodiments.
  • the oil soluble or oil dispersible monomer and the aziridine crosslinking agent may be reacted in a medium having a pH greater than 4.
  • the lipophlic monomer and the aziridine crosslinking agent may be reacted in a medium having a pH greater than 6; a pH greater than 7 in other embodiments; a pH greater than 8 in other embodiments; a pH greater than 9 in yet other embodiments.
  • Reagents which may be used to adjust the pH may include alkali metal hydroxides, such as sodium hydroxide, potassium hydroxide, calcium hydroxide, and rubidium hydroxide, lithium hydroxides, benzyltrimethylammonium hydroxides, and the partially neutralized salts of organic acids, such as tri-sodium ethylenediaminetetraacetic acid.
  • the alkali metal hydroxide, pH adjusting agent, or buffer may act as a catalyst, effecting or enhancing the crosslinking reaction between the oil soluble or oil dispersible monomer and the crosslinking agent.
  • the viscosity may be varied to obtain a desired degree of flow sufficient for decreasing the flow of water through or increasing the load-bearing capacity of a formation.
  • the viscosity of the solution may be varied by increasing or decreasing the amount of solvent relative to the aziridine crosslinking agents and oil soluble or oil dispersible monomer, by employing viscosifying agents, or by other techniques common in the art.
  • the combined amount of oil soluble or oil dispersible monomer and aziridine crosslinking agents may range from 0.5 to 100 weight percent, based upon the total weight of solvent in the solution. In other embodiments, the combined amount of oil soluble or oil dispersible monomer and aziridine crosslinking agents may range from 5 to 100 weight percent, based upon the total weight of solvent in the solution; from 20 to 70 weight percent in other embodiments; from 25 to 65 weight percent in yet other embodiments. As used herein, total weight of solvent is exclusive of any water added with pH adjusting reagents.
  • the reaction of the oil soluble or oil dispersible monomer and the crosslinking agent may produce gels having a consistency ranging from a viscous sludge to a hard gel.
  • the reaction of the oil soluble or oil dispersible monomer and the crosslinking agent may result in a soft elastic gel.
  • the reaction may result in a good gel; in a hard gel in yet other embodiments.
  • the hardness of the gel is the force necessary to break the gel structure, which may be quantified by measuring the force required for a needle to penetrate the crosslinked structure. Hardness is a measure of the ability of the gel to resist to an established degree the penetration of a test needle driven into the sample at a constant speed.
  • Hardness may be measured by using a Brookfield QTS-25 Texture Analysis
  • This instrument consists of a probe of changeable design that is connected to a load cell.
  • the probe may be driven into a test sample at specific speeds or loads to measure the following parameters or properties of a sample: springiness, adhesiveness, curing, breaking strength, fracturability, peel strength, hardness, cohesiveness, relaxation, recovery, tensile strength burst point, and spreadability.
  • the hardness may be measured by driving a 4mm diameter, cylindrical, flat faced probe into the gel sample at a constant speed of 30 mm per minute. When the probe is in contact with the gel, a force is applied to the probe due to the resistance of the gel structure until it fails, which is recorded via the load cell and computer software. As the probe travels through the sample, the force on the probe is measured.
  • the force on the probe may be recorded providing an indication of the gel's overall hardness.
  • the initial peak force may be recorded at the point the gel first fails, close to the first contact point, followed by recording highest and lowest values measured after this point where the probe is travelling through the bulk of the gel.
  • Non-aqueous gels useful in downhole applications may comprise gels with a hardness ranging from about 10 to 7,000 psi. In other embodiments, the gel may have a hardness ranging from about 100 to 5,000 psi, and from 300 to 2,000 psi in yet other embodiments.
  • Some embodiments of the gels or beads disclosed herein may be formed in a one- solution single component system, where the aziridine crosslinking agent(s) are premixed with the oil soluble or oil dispersible monomer (material to be crosslinked). The mixture may then be placed or injected prior to cure. The gel times and bead formation times may be adjusted by adjusting the concentration of the solvent, reactants, and hardening agents, such as inorganic base or tertiary amine, in the solution.
  • gels and beads disclosed herein may also be formed in a two-component system, where the aziridine crosslinking and oil soluble or oil dispersible monomers may be mixed separately and combined immediately prior to injection.
  • the aziridine crosslinking agent may be added neat, or in a solution of a solvent without an active H.
  • one reagent, the aziridine crosslinking agent or oil soluble or oil dispersible monomer may be placed in the wellbore or the near-wellbore region where it may then be contacted by the other reagent, either the aziridine crosslinking agent or oil soluble or oil dispersible monomer as required.
  • Gel times or bead formation times may be adjusted by varying the ratio of reactant, the concentration of tertiary amine catalyst, and quantity of solvent.
  • Embodiments of the gels disclosed herein may be used in applications including: as an additive in drilling muds, in particular oil based muds, and as an additive in loss circulation material (LCM) pills; wellbore (WB) strengthening treatments.
  • LCM loss circulation material
  • WB wellbore
  • the gels disclosed herein may also find use in other downhole applications, such as insulating packer fluids and remediations for sustained casing pressure, where gel treatments may be typically used.
  • gels and beads disclosed herein may be used as an additive in drilling mud.
  • Drilling fluids or muds typically include a base fluid (for example water, diesel or mineral oil, or a synthetic compound), weighting agents (for example, barium sulfate or barite may be used), bentonite clay, and various additives that serve specific functions, such as polymers, corrosion inhibitors, emulsifiers, and lubricants.
  • a base fluid for example water, diesel or mineral oil, or a synthetic compound
  • weighting agents for example, barium sulfate or barite may be used
  • bentonite clay various additives that serve specific functions, such as polymers, corrosion inhibitors, emulsifiers, and lubricants.
  • Gels and beads described by the procedures above may be included in a wellbore fluid.
  • the wellbore fluids may include an oleaginous continuous phase, a non-oleaginous discontinuous phase, and a gel as disclosed herein.
  • modifications may include the degree of crosslinking, and/or the nature of the oil soluble or oil dispersible monomer or aziridine crosslinking agent.
  • the oleaginous fluid may be a liquid and more preferably is a natural or synthetic oil and more preferably the oleaginous fluid is selected from the group including diesel oil; mineral oil; a synthetic oil, such as hydrogenated and unhydrogenated olefins including polyalphaolefins, linear and branch olefins and the like, polydiorganosiloxanes, siloxanes, or organosiloxanes, esters of fatty acids, specifically straight chain, branched and cyclical alkyl ethers of fatty acids, mixtures thereof and similar compounds known to one of skill in the art; and mixtures thereof.
  • diesel oil such as hydrogenated and unhydrogenated olefins including polyalphaolefins, linear and branch olefins and the like, polydiorganosiloxanes, siloxanes, or organosiloxanes, esters of fatty acids, specifically straight chain, branched and cyclical alkyl ethers
  • the concentration of the oleaginous fluid should be sufficient so that an invert emulsion forms and may be less than about 99% by volume of the invert emulsion.
  • the amount of oleaginous fluid is from about 30% to about 95% by volume and more preferably about 40% to about 90% by volume of the invert emulsion fluid.
  • the oleaginous fluid may include at least 5% by volume of a material selected from the group including esters, ethers, acetals, dialkylcarbonates, hydrocarbons, and combinations thereof.
  • the non-oleaginous fluid used in the formulation of the invert emulsion fluid disclosed herein is a liquid and preferably is an aqueous liquid. More preferably, the non-oleaginous liquid may be selected from the group including sea water, a brine containing organic and/or inorganic dissolved salts, liquids containing water-miscible organic compounds and combinations thereof.
  • the amount of the non-oleaginous fluid is typically less than the theoretical limit needed for forming an invert emulsion. Thus the amount of non-oleaginous fluid is less than about 70% by volume and preferably from about 1% to about 70% by volume.
  • the non-oleaginous fluid is preferably from about 5% to about 60% by volume of the invert emulsion fluid.
  • the fluid phase may include either an aqueous fluid or an oleaginous fluid, or mixtures thereof.
  • coated barite or other weighting agents may be included in a wellbore fluid comprising an aqueous fluid that includes at least one of fresh water, sea water, brine, and combinations thereof.
  • the fluids disclosed herein are especially useful in the drilling, completion and working over of subterranean oil and gas wells.
  • the fluids disclosed herein may find use in formulating drilling muds and completions fluids that allow for the easy and quick removal of the filter cake.
  • Such muds and fluids are especially useful in the drilling of horizontal wells into hydrocarbon bearing formations.
  • drilling fluids disclosed herein in a manner analogous to those normally used, to prepare conventional oil-based drilling fluids.
  • a desired quantity of oleaginous fluid such as a base oil and a suitable amount of the surfactant described above are mixed together and the remaining components are added sequentially with continuous mixing.
  • An invert emulsion may be formed by vigorous agitating, mixing or shearing the oleaginous fluid and the non-oleaginous fluid.
  • additives that may be included in the wellbore fluids disclosed herein include for example, wetting agents, organophilic clays, viscosifiers, fluid loss control agents, surfactants, dispersants, interfacial tension reducers, pH buffers, mutual solvents, thinners, thinning agents and cleaning agents.
  • wetting agents for example, wetting agents, organophilic clays, viscosifiers, fluid loss control agents, surfactants, dispersants, interfacial tension reducers, pH buffers, mutual solvents, thinners, thinning agents and cleaning agents.
  • the addition of such agents should be well known to one of ordinary skill in the art of formulation of drilling fluids and muds.
  • the gels may form a filter cake or one component of a filter cake that forms along the wellbore as drilling progresses.
  • the gels contained in the drilling fluid may be deposited along the wellbore throughout the drilling process, potentially strengthening the wellbore by stabilizing shale formations and other sections encountered while drilling. Improved wellbore stability may reduce the occurrence of stuck pipe, hole collapse, hole enlargement, lost circulation, and may improve well control.
  • Wellbore stability may also be enhanced by the injection of a low viscosity mixture of an oil soluble or oil dispersible monomer and an aziridine crosslinking agent into formations along the wellbore. The mixture may then continue to react, strengthening the formation along the wellbore upon gellation of the mixture.
  • the gels and beads disclosed herein may aid in lifting solid debris from tubing walls and through the tubing annulus. Hard gels and beads circulating through the drill pipe during drilling may scrape and clean the drill pipe, removing any pipe scale, mud, clay, or other agglomerations that may have adhered to the drill pipe or drill tubing. In this manner, the drill pipe may be maintained free of obstructions that could otherwise hinder removal of drilled solids from the drill pipe during drilling.
  • Embodiments of the gels disclosed herein may be used to enhance secondary oil recovery efforts.
  • secondary oil recovery it is common to use an injection well to inject a treatment fluid, such as water or brine, downhole into an oil-producing formation to force oil toward a production well.
  • a treatment fluid such as water or brine
  • Thief zones and other permeable strata may allow a high percentage of the injected fluid to pass through only a small percentage of the volume of the reservoir, for example, and may thus require an excessive amount of treatment fluid to displace a high percentage of crude oil from a reservoir.
  • embodiments of the gels and beads disclosed herein may be injected into the formation.
  • Gels and beads injected into the formation may partially or wholly restrict flow through the highly conductive zones. In this manner, the gels and beads may effectively reduce channeling routes through the formation, forcing the treating fluid through less porous zones, and potentially decreasing the quantity of treating fluid required and increasing the oil recovery from the reservoir.
  • gels and beads may also be formed in situ within the formation to combat the thief zones.
  • Oil soluble or oil dispersible monomers may be injected into the formation, allowing the oil soluble or oil dispersible monomers to penetrate further into the formation than if a gel was injected.
  • the crosslinking agents may then be injected, causing the previously injected oil soluble or oil dispersible monomers to crosslink within the formation.
  • gels and beads disclosed herein may be used as one component in a drilling fluid.
  • the gels and beads may form part of a filter cake, minimizing seepage of drilling fluids to underground formations and lining the wellbore.
  • embodiments of the gels and beads disclosed herein may be used as one component in loss circulation material (LCM) pills that are used when excessive seepage or circulation loss problems are encountered, requiring a higher concentration of loss circulation additives.
  • LCM pills are used to prevent or decrease loss of drilling fluids to porous underground formations encountered while drilling.
  • the crosslinking agent and oil soluble or oil dispersible monomer / material may be mixed prior to injection of the pill into the drilled formation.
  • the mixture may be injected while maintaining a low viscosity, prior to gel formation, such that the gel may be formed downhole.
  • the gelling material and crosslinking agent may be injected into the formation in separate shots, mixing and reacting to form a gel or bead in situ (in the formation following injection of the LCM pill shots). In this manner, premature gel or bead formation may be avoided.
  • a first mixture containing a oil soluble or oil dispersible monomer may be injected into the wellbore and into the lost circulation zone.
  • a second mixture containing a crosslinking agent and/or pH modifier may be injected, causing the oil soluble or oil dispersible monomer to crosslink in situ to the point that the gel expands in size.
  • the expanded and hardened gel or bead may plug fissures and thief zones, closing off the lost circulation zone.
  • a gel was synthesized by mixing UNIDYME® 30 with various aziridine crosslinking agents in a base oil as shown in Table 1 below. After heating at 95°C for about two days, the samples were inspected for gel formation. Any resultant gels were tested for peak gel hardness on a texture analyzer at a penetration rate of 20mm/minute with a 4mm diameter probe. TABLE l
  • Samples 1-4 showed increased thickness with increased dose of the CORIAL AN crosslinker.
  • Samples 5-8 formed gels with brown surface layers. A progressive increase in gel hardness is observed with increasing dose of the ICAPLINK X5 crosslinking agent.
  • a gel was synthesized by mixing EMI 759 with various aziridine crosslinking agents as shown in Table 2 below. After heating at 95°C for about two days, the samples were inspected for gel formation. Any resultant gels were tested for peak gel hardness on a texture analyzer at a penetration rate of 20mm/minute with a 4mm diameter probe. TABLE 2
  • Sample 12 gelled instantaneously. Samples 14-17 remained as low viscosity brown liquids.
  • Advantages of the current disclosure may include a non-aqueous gel or beads with excellent ability to vary the gel properties based on a variety of applications. Adjustable gellation times, temperatures, and physical properties of the resulting gel may be selected for a particular desired application. Non-aqueous gels and beads of the present disclosure may be selected to have desired strength, flexibility, water resistance, and appropriate hardness for use in applications such as lost circulation, as bridging materials, to contain and deliver a biocide through slow release, in lubrication, water shutoff treatments, and other uses in subterranean wells.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

L'invention porte, selon des modes de réalisation, sur des gels non aqueux destinés à être utilisés dans des applications de fond de puits contenant le produit réactionnel d'au moins un monomère soluble dans l'huile ou dispersible dans l'huile et d'au moins un agent de réticulation aziridine, ledit ou lesdits monomères solubles dans l'huile ou dispersibles dans l'huile et l'agent de réticulation aziridine étant combinés en une solution non aqueuse. L'invention porte également sur des procédés comprenant l'utilisation de ces gels non aqueux.
PCT/EP2009/060117 2008-08-05 2009-08-04 Agents de réticulation aziridines pour la fabrication de gels non aqueux et de billes de polymère pour des applications en champ pétrolifère WO2010015639A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US8633808P 2008-08-05 2008-08-05
US61/086,338 2008-08-05

Publications (1)

Publication Number Publication Date
WO2010015639A1 true WO2010015639A1 (fr) 2010-02-11

Family

ID=41211687

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2009/060117 WO2010015639A1 (fr) 2008-08-05 2009-08-04 Agents de réticulation aziridines pour la fabrication de gels non aqueux et de billes de polymère pour des applications en champ pétrolifère

Country Status (1)

Country Link
WO (1) WO2010015639A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9932512B1 (en) 2017-08-22 2018-04-03 Saudi Arabian Oil Company Compositions with polyaziridine crosslinkers for treating subterranean formations
US9970246B2 (en) 2012-04-09 2018-05-15 M-I L.L.C. Triggered heating of wellbore fluids by carbon nanomaterials

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030104283A1 (en) * 2001-10-30 2003-06-05 Samsung Sdi Co., Ltd Polymer electrolyte, rechargeable lithium battery and method of preparing rechargeable lithium battery
US20070249504A1 (en) * 2006-04-20 2007-10-25 M-I Llc Aqueous gels for well bore strengthening
WO2009006253A2 (fr) * 2007-06-28 2009-01-08 M-I Llc Gels dégradables dans des applications d'isolation zonale

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030104283A1 (en) * 2001-10-30 2003-06-05 Samsung Sdi Co., Ltd Polymer electrolyte, rechargeable lithium battery and method of preparing rechargeable lithium battery
US20070249504A1 (en) * 2006-04-20 2007-10-25 M-I Llc Aqueous gels for well bore strengthening
WO2007124442A1 (fr) * 2006-04-20 2007-11-01 M-I Llc Gels aqueux pour le renforcement de forages de puits
WO2009006253A2 (fr) * 2007-06-28 2009-01-08 M-I Llc Gels dégradables dans des applications d'isolation zonale

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9970246B2 (en) 2012-04-09 2018-05-15 M-I L.L.C. Triggered heating of wellbore fluids by carbon nanomaterials
US9932512B1 (en) 2017-08-22 2018-04-03 Saudi Arabian Oil Company Compositions with polyaziridine crosslinkers for treating subterranean formations
US10113100B1 (en) 2017-08-22 2018-10-30 Saudi Arabia Oil Company Compositions with polyaziridine crosslinkers for treating subterranean formations
CN111194345A (zh) * 2017-08-22 2020-05-22 沙特阿拉伯石油公司 用于处理地下地层的具有聚氮丙啶交联剂的组合物

Similar Documents

Publication Publication Date Title
CA2775996C (fr) Agents de reticulation pour la fabrication de gels et de billes polymeres pour applications petroliferes
EP2027228B1 (fr) Gel non aqueux pour consolidation de forages
EP1866516B1 (fr) Liquide de completion et de deplacement a base d'une emulsion inverse, et procede d'utilisation
US8592354B2 (en) Water based completion and displacement fluid and method of use
EP2113015B1 (fr) Liquide de rupture et de déplacement et procédé d'utilisation
US11499087B2 (en) Thermally responsive lost circulation materials
WO2010015639A1 (fr) Agents de réticulation aziridines pour la fabrication de gels non aqueux et de billes de polymère pour des applications en champ pétrolifère
AU2018342586B2 (en) Methods for wellbore strengthening
WO2020102149A1 (fr) Procédés de renforcement de puits de forage
US11292951B2 (en) Thermally responsive anti-sag agents

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 09781489

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 09781489

Country of ref document: EP

Kind code of ref document: A1