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CN-121991272-A - Interpenetrating network polymer plugging agent for drilling fluid and preparation method and application thereof

CN121991272ACN 121991272 ACN121991272 ACN 121991272ACN-121991272-A

Abstract

The invention provides an interpenetrating network polymer plugging agent for drilling fluid, and a preparation method and application thereof, and the interpenetrating network polymer plugging agent comprises the following steps of 1) mixing water, an emulsifying agent A, an emulsifying agent B and a water-soluble monomer C to obtain a water phase, 2) mixing the water phase, an oil-soluble monomer A (hard monomers) and a cross-linking agent D, emulsifying to obtain an emulsion reaction mixed solution, 3) mixing the emulsion reaction mixed solution and a first-stage initiator solution, carrying out heat preservation polymerization to obtain a polymerized emulsion, and 4) mixing the polymerized emulsion, an oil-soluble monomer B (soft monomers), a cross-linking agent E and a second-stage initiator solution, and continuing carrying out heat preservation polymerization to obtain the interpenetrating network polymer plugging agent for the drilling fluid. The plugging agent prepared by the method can give consideration to elastic deformation, adhesive action and temperature resistance (200 ℃), has good compatibility with oil-based drilling fluid and water-based drilling fluid, and has obvious filtration reducing and plugging effects.

Inventors

  • LIU WENTANG
  • ZHANG XIANMIN
  • HUANG NING
  • HU XIAOYAN
  • JIANG XUEQING
  • YIN YULONG

Assignees

  • 中石化石油工程技术服务股份有限公司
  • 中石化中原石油工程有限公司
  • 中石化中原石油工程有限公司钻井工程技术研究院

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. The preparation method of the interpenetrating network polymer plugging agent for the drilling fluid comprises the following steps: 1) Mixing water, an emulsifier A, an emulsifier B and a water-soluble monomer C to obtain a water phase; 2) Mixing the water phase, the oil-soluble monomer A and the cross-linking agent D, and emulsifying to obtain an emulsion reaction mixed solution; 3) Mixing the emulsion reaction mixed solution with a primary initiator solution, and carrying out heat preservation polymerization to obtain a polymerized emulsion; 4) And mixing the emulsion after polymerization with an oil-soluble monomer B, a cross-linking agent E and a two-stage initiator solution, and continuing to perform heat preservation polymerization to obtain the interpenetrating network polymer plugging agent for the drilling fluid.
  2. 2. The preparation method according to claim 1, wherein the emulsifier a in step 1) is selected from one or more of sodium alkyl sulfate, sodium alkylbenzenesulfonate, sodium dialkyl-2-sulfosuccinate and sodium alkyl allyloxy polyoxyethylene phosphate; The emulsifier B is one or more selected from polyoxyethylene alkyl ether, polyoxyethylene phenol ether, polyoxyethylene sorbitan ether stearate and polyoxyethylene sorbitan monooleate; the water-soluble monomer C is selected from one or more of methacrylic acid, acrylamide, acrylic acid and AMPS.
  3. 3. The process according to claim 1, wherein in step 2) the oil-soluble monomer a is selected from styrene and/or methyl methacrylate; the cross-linking agent D is selected from one or more of N, N' -methylene bisacrylamide, polyvinyl alcohol bisacrylate, 1, 3-butadiene and 1, 4-divinylbenzene.
  4. 4. The method of claim 1, wherein the initiator in the first initiator solution in step 3) and the initiator in the second initiator solution in step 4) are independently selected from one or more of potassium persulfate, ammonium persulfate, and sodium persulfate.
  5. 5. The preparation method according to claim 1, wherein the oil-soluble monomer B in the step 4) is one or more selected from the group consisting of butyl methacrylate, methyl acrylate, vinyl acetate, butyl acrylate and isooctyl acrylate; The cross-linking agent E is selected from one or more of N, N' -methylene bisacrylamide, polyvinyl alcohol bisacrylate, 1, 3-butadiene and 1, 4-divinylbenzene.
  6. 6. The preparation method according to claim 1, wherein the temperature of the thermal-insulation polymerization and the polymerization continuing to be thermal-insulation polymerized is 70-80 ℃.
  7. 7. The preparation method of claim 1, wherein the water-soluble monomer C accounts for 10% -20% of the total mass of the oil-soluble monomer A, the oil-soluble monomer B and the water-soluble monomer C, the oil-soluble monomer A accounts for 50% -70%, and the oil-soluble monomer B accounts for 20% -40%.
  8. 8. The preparation method of claim 1, wherein the total addition of the cross-linking agent is 0.1% -0.5%, the total addition of the initiator is 0.5% -2.0% and the addition of the emulsifying agent A and the emulsifying agent B are 2% -3% based on the total mass of the oil-soluble monomer A, the oil-soluble monomer B and the water-soluble monomer C; The pH value of the water phase is regulated to 7.5-8.5 by a 20% NaOH aqueous solution.
  9. 9. An interpenetrating network polymer plugging agent for drilling fluid prepared by the preparation method of any one of claims 1 to 8; the particle size of the interpenetrating network polymer plugging agent for the drilling fluid is 0.05-50 mu m, and D 50 is less than or equal to 15 mu m.
  10. 10. Use of an interpenetrating network polymer plugging agent for drilling fluids prepared by the preparation method of any one of claims 1-8 in oil-based drilling fluids, water-based drilling fluids, or high-temperature formations above 200 ℃.

Description

Interpenetrating network polymer plugging agent for drilling fluid and preparation method and application thereof Technical Field The invention belongs to the technical field of drilling fluid treatment agents in petroleum drilling engineering, and particularly relates to an interpenetrating network polymer plugging agent for drilling fluid, and a preparation method and application thereof. Background In deep well ultra-deep well drilling, the problems of low pressure leakage, unstable stress, collapse and instability of the well wall and the like are frequent, the risks of lost circulation and blocking of the well are high, the treatment difficulty is high, and water-based and oil-based drilling fluids are generated. For example, the crack development of the red star block Wu Guping, the collapse and leakage coexist, the shale stratum of the Longmaxi group from tribute and Weiyuan blocks, the crushing stress release of the stratum of the industrial 7-well the Eastern Mountain temple is serious, and the geological crushing of the North Sang Damu group limestone, the southwest work area, the mouth group and the like is realized. When the drilling meets the micro-nano pore to develop the stratum, the phenomena of drilling fluid leakage and well wall instability collapse are easy to occur, the micro-nano plugging material is needed to be added to form a compact plugging layer, the invasion of the drilling fluid is reduced, the stratum bearing capacity is improved, the collapse caused by leakage is prevented, and meanwhile, the material is required to have a certain bonding effect to play a role in bonding and protecting the wall for further improving the collapse prevention effect. The elastic deformation, the bonding effect and the temperature resistance (200 ℃) of the common polymer plugging material cannot be simultaneously considered, and the high-temperature plugging leakage-proof and collapse-proof effects cannot be simultaneously met. Disclosure of Invention In view of the above, the invention aims to provide an interpenetrating network polymer plugging agent for drilling fluid, a preparation method and application thereof, wherein the plugging agent prepared by the method has good temperature resistance, good compatibility with oil-based drilling fluid and water-based drilling fluid, and obvious filtration reducing and plugging effects. The invention provides a preparation method of an interpenetrating network polymer plugging agent for drilling fluid, which comprises the following steps: 1) Mixing water, an emulsifier A, an emulsifier B and a water-soluble monomer C to obtain a water phase; 2) Mixing the water phase, the oil-soluble monomer A and the cross-linking agent D, and emulsifying to obtain an emulsion reaction mixed solution; 3) Mixing the emulsion reaction mixed solution with a primary initiator solution, and carrying out heat preservation polymerization to obtain a polymerized emulsion; 4) And mixing the emulsion after polymerization with an oil-soluble monomer B, a cross-linking agent E and a two-stage initiator solution, and continuing to perform heat preservation polymerization to obtain the interpenetrating network polymer plugging agent for the drilling fluid. The invention mixes water, emulsifier A, emulsifier B and water-soluble monomer C to obtain water phase. The emulsifier A is selected from one or more of sodium alkyl sulfate, sodium alkyl benzene sulfonate, dialkyl-2-sulfosuccinate and alkyl allyloxy polyoxyethylene sodium phosphate, the emulsifier B is selected from one or more of polyoxyethylene alkyl ether, polyoxyethylene phenol ether, polyoxyethylene sorbitan ether stearate and polyoxyethylene sorbitan monooleate, and the water-soluble monomer C is selected from one or more of methacrylic acid, acrylamide, acrylic acid and AMPS. The water-soluble monomer C can improve the hydrophilicity of the plugging agent. The pH value of the water phase is preferably adjusted to 7.5-8.5 through a 20% NaOH aqueous solution. After obtaining the water phase, the invention mixes the water phase, the oil-soluble monomer A and the cross-linking agent D, and emulsifies to obtain the emulsification reaction mixed solution. The time of the emulsification reaction is 25-35 min, preferably 28-32 min, and in the specific embodiment, the time of the emulsification is 30min. In the invention, the emulsification is carried out under the stirring condition, the stirring speed is 580-620 rpm, preferably 590-610 rpm, and in the specific embodiment, the stirring speed is 600rpm. The invention is fully emulsified under N 2 atmosphere. The oil-soluble monomer A is a hard monomer substance, the glass transition temperature of a homopolymer of the oil-soluble monomer A is higher than-20 ℃, the rigidity and hardness of the plugging agent can be improved, the oil-soluble monomer A is selected from hard monomers such as styrene and/or methyl methacrylate, and the crosslinking agent D is selected from one or more