Abstract: The present disclosure a leak-proof lost-circulation control water-based drilling fluid composition and preparation method and use thereof.

Abstract: A preparation method of a fully adaptive modified nanographene plugging type anti-collapse drilling fluid is disclosed. A modified nanographene slurry anti-collapse agent and a water-based drilling fluid containing the modified nanographene slurry anti-collapse agent are disclosed. The preparation method includes subjecting a nanographene and a mixed acid to a first contact to obtain a mixed liquid, dropwise adding potassium chlorate into the mixed liquid under the condition of ice-bath pan to carry out a modification treatment, so as to obtain a modified nanographene, and subjecting the modified nanographene to a second contact with water to prepare a modified nanographene slurry.

Abstract: An oil-based drilling fluid composition, includes a base fluid and a treating agent. The base fluid comprises a base oil and an inhibitor; the treating agent comprises an organic soil, a main emulsifier, an auxiliary emulsifier, a plugging agent, a weighting agent, a humectant, an alkaline regulator and a filtrate reducer. 5-25 parts by weight of the inhibitor, 5-12 parts by weight of the organic soil, 1-6 parts by weight of the main emulsifier, 2-8 parts by weight of the auxiliary emulsifier, 3-18 parts by weight of the plugging agent, 5-30 parts by weight of the weighting agent, 2-6 parts by weight of the humectant, 2-7 parts by weight of the alkaline regulator and 2-10 parts by weight of the filtrate reducer are used, based on 100 parts by weight of base oil.

Abstract: The present disclosure a pressure-bearing plugging agent, comprises a core, a first coating layer and a second coating layer which are sequentially coated on an outer surface of the core, wherein the core is made of a water-absorbing swellable material, the first coating layer is a paraffin layer, and the second coating layer is obtained by cementing the rigid particles with an adhesive.

Abstract: The present disclosure discloses an oil-based drilling fluid composition, including a base fluid and a treating agent, wherein the base fluid comprises a base oil and an inhibitor; the treating agent comprises an organic soil, a main emulsifier, an auxiliary emulsifier, a plugging agent, a weighting agent, a humectant, an alkaline regulator and a filtrate reducer; wherein 5-25 parts by weight of the inhibitor, 5-12 parts by weight of the organic soil, 1-6 parts by weight of the main emulsifier, 2-8 parts by weight of the auxiliary emulsifier, 3-18 parts by weight of the plugging agent, 5-30 parts by weight of the weighting agent, 2-6 parts by weight of the humectant, 2-7 parts by weight of the alkaline regulator and 2-10 parts by weight of the filtrate reducer are used, based on 100 parts by weight of base oil.

Abstract: A method of preparing a modified polyvinyl acetate includes subjecting a mixed liquor L1 containing a functional monomer to a first reaction with a first vinyl acetate monomer, followed by adding a first initiator to carry out a second reaction to obtain a mixed liquor L2; subjecting an acrylate monomer, a second vinyl acetate monomer, a second initiator and the mixed liquor L2 to carry out a third reaction to obtain a mixed liquor L3; and subjecting a third initiator and the mixed liquor L3 to carry out a fourth reaction under the air-tight and ultrasonic conditions. The functional monomer is selected from acrylic acid, oleic acid or butenedioic acid. Uses of modified polyvinyl acetate obtained by the method and oil-based drilling fluid containing the modified polyvinyl acetate are also disclosed.

Abstract: The present disclosure a pressure-bearing plugging agent, comprises a core, a first coating layer and a second coating layer which are sequentially coated on an outer surface of the core, wherein the core is made of a water-absorbing swellable material, the first coating layer is a paraffin layer, and the second coating layer is obtained by cementing the rigid particles with an adhesive.

Abstract: The present discloses a pressure-bearing plugging composition comprising 1-7 parts by weight bentonite, 0.1-1.5 parts by weight deformation material, 8-18 parts by weight filling material and 4-12 parts by weight modified bridging material, based on 100 parts by weight of water; the modified bridging material comprises a core, and a coating layer coated on an outer surface of the core, and a paraffin layer disposed between the core and the coating layer; the core is made of a water-absorbing material, and the coating layer is formed by bonding rigid particles and an adhesive.

Abstract: A fiber silica composite microsphere for a shale stratum comprises a hollow silica sphere and fibers, and the fibers are partially coated on an outer surface of the hollow silica sphere and partially embedded into an interior of the hollow silica sphere. The hollow silica sphere has an outer diameter of 1-5 ?m and an inner diameter of 0.8-4.7 ?m; the fibers have a length of 5-10 ?m and a width of 1-3 ?m.

Abstract: The present invention relates to a drilling fluid for enhancing stratum pressure bearing capacity, and a method of preparing and using the drilling fluid. The drilling fluid comprises water, bentonite, low adhesive aggregation anionic cellulose, lignite resin, high temperature resistant and salt resistant filtrate reducer, silanol inhibitor, inorganic micrometer-nanometer rigid particles and emulsified asphalt. The bentonite is 2-9 parts by weight, the low adhesive aggregation anionic cellulose is 0.1-1 parts by weight, the lignite resin is 1-5 parts by weight, the high temperature resistant and salt resistant filtrate reducer is 0.1-2 parts by weight, the silanol inhibitor is 0.1-2 parts by weight, the inorganic micrometer-nanometer rigid particles are 0.5-5 parts by weight, and the emulsified asphalt is 1-10 parts by weight, based on 100 parts by weight of water.

Abstract: A nanometer plugging water-based drilling fluid and preparation method and use thereof are within this disclosure. The nanometer plugging water-based drilling fluid comprise a nanometer plugging agent. The nanometer plugging agent may be surface modified SiO2 powder with the surfactant. The surfactant may be sodium dodecyl benzene sulfonate and/or sodium dodecyl sulfate. The nanometer plugging water-based drilling fluid may perform effective anti-collapse of stratum and maintain the stability of stratum.

Abstract: A nanometer plugging water-based drilling fluid and preparation method and use thereof are within this disclosure. The nanometer plugging water-based drilling fluid comprise a nanometer plugging agent. The nanometer plugging agent may be surface modified SiO2 powder with the surfactant. The surfactant may be sodium dodecyl benzene sulfonate and/or sodium dodecyl sulfate. The nanometer plugging water-based drilling fluid may perform effective anti-collapse of stratum and maintain the stability of stratum.

Abstract: The invention discloses a method and system for obtaining an evaluation model and an evaluation method and system for the plugging performance of drilling fluid. The method for obtaining the evaluation model comprises: applying a confining pressure to a holding device where a preset fracture model is located, wherein a displacement differential pressure of two ends of the holding device is a preset displacement differential pressure; measuring a flow of standard measuring fluid flowing through the preset fracture model under different confining pressures, wherein the different confining pressures gradually increase according to a first preset rule; and controlling to stop increasing the confining pressure when the flow of the standard measuring fluid flowing through the preset fracture model reaches a preset flow so as to compress the preset fracture model into the evaluation model at a micro-nano level.

Abstract: The present invention relates to an experimental device for testing the lubricity in horizontal well drilling with a cuttings bed taken into consideration, which comprises a simulated wellbore with a pulley provided at one end and a hydraulic cylinder fixed and a drill rod mounted at the other end; a cuttings feeding port is arranged above the simulated wellbore; a low end of the simulated wellbore is connected with a liquid return pipeline; the simulated wellbore is provided with an ultrasonic probe and is connected with a rock core holder. The present invention is in line with the actual operating conditions because it not only takes consideration of the friction force between the drill string and the drilling fluid, wellbore wall and slurry cake, but also takes consideration of the friction force between the drill string and the cuttings bed.

Abstract: The invention relates to the field of drilling fluid, and provides a multi-functional weighting agent for drilling fluid and preparation method thereof, and water-based drilling fluid and use thereof, wherein the multi-functional weighting agent is an polyacrylamide/modified barium sulfate composite multi-functional weighting agent prepared by sequentially dropwise adding acrylamide and ammonium persulfate to a mixture of modified barium sulfate and deionized water in a presence of an initiator.

Abstract: The invention relates to the field of drilling fluid, and provides a multi-functional weighting agent for drilling fluid and preparation method thereof, and water-based drilling fluid and use thereof, wherein the multi-functional weighting agent is an polyacrylamide/modified barium sulfate composite multi-functional weighting agent prepared by sequentially dropwise adding acrylamide and ammonium persulfate to a mixture of modified barium sulfate and deionized water in a presence of an initiator.

Abstract: A micro-nanometer plugging anti-collapse drilling fluid and fracturing method and use thereof.

Abstract: The present disclosure discloses a modified nano-silica plugging agent, a water-based drilling fluid, and a preparation method and use thereof.

Abstract: Disclosed is an experimental device for testing the lubricity in horizontal well drilling with a cuttings bed taken into consideration, which comprises a simulated wellbore with a pulley provided at one end and a hydraulic cylinder fixed and a drill rod mounted at the other end, wherein the drill rod is connected with a driving mechanism and a rotating mechanism, and is provided with thrust and torque sensors; a cuttings feeding port is arranged above the simulated wellbore and connected to a slurry tank through a liquid feeding pipeline, and a high-pressure pump, a flowmeter and a pressure sensor are arranged on the liquid feeding pipeline; the low end of the simulated wellbore is connected with a liquid return pipeline, and a temperature-reducing and pressure-reducing mechanism, a flowmeter and a transfer pump are arranged on the liquid return pipeline; the simulated wellbore is provided with an ultrasonic probe and is connected with a rock core holder that is provided with a heating mechanism, a rock core

Abstract: An expandable plugging agent is described. The expandable plugging agent is obtained through a polymerization reaction of acrylamide, a strength improving material, an acrylate, and gelatinized colloid, the acrylate is obtained through a neutralization reaction of an acidity neutralizer and acrylic acid, and the gelatinized colloid is obtained through a gelatinization reaction of starch in deionized water.