Abstract: The present invention relates to the field of drilling fluids, and discloses a strong plugging drilling fluid suitable for shale gas wells and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, a tackifier, a flow pattern regulator, a filtrate reducer, a plugging agent, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 1-10 parts by weight, the content of the tackifier is 5-15 parts by weight, the content of the flow pattern regulator is 4-13 parts by weight, the content of the filtrate reducer is 4-13 parts by weight, the content of the plugging agent is 20-55 parts by weight, and the content of the weighting agent is 10-60 parts by weight; the drilling fluid provided in the present invention employs modified nano-silica as a plugging agent to improve dispersity and particle size distribution in the drilling fluid system.

Abstract: The present invention relates to the field of drilling fluids, and discloses a strong plugging drilling fluid suitable for shale gas wells and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, a tackifier, a flow pattern regulator, a filtrate reducer, a plugging agent, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 1-10 parts by weight, the content of the tackifier is 5-15 parts by weight, the content of the flow pattern regulator is 4-13 parts by weight, the content of the filtrate reducer is 4-13 parts by weight, the content of the plugging agent is 20-55 parts by weight, and the content of the weighting agent is 10-60 parts by weight; the drilling fluid provided in the present invention employs modified nano-silica as a plugging agent to improve dispersity and particle size distribution in the drilling fluid system.

Abstract: The present invention discloses a micro-nano composite plugging agent for drilling fluid, a preparation method of the micro-nano composite plugging agent for drilling fluid, a drilling fluid, and an application thereof. The composite plugging agent contains nanometer calcium carbonate, nanometer zinc oxide whiskers, nanometer emulsified paraffin, a flocculating agent, and a lubricant, wherein in the composite plugging agent, the nanometer calcium carbonate is in 10-36 parts by weight, the nanometer zinc oxide whiskers are in 20-40 parts by weight, the nanometer emulsified paraffin is in 30-70 parts by weight, the flocculating agent is in 1-10 parts by weight, and the lubricant is 5-20 parts by weight.

Abstract: A gel plugging slurry for well drilling, comprising water, special gel, bridging material, linking material, and packing material, wherein based on 100 parts by weight of the water, the amount of the special gel is 1-15 parts by weight, the amount of the bridging material is 8-20 parts by weight, the amount of the linking material is 20-40 parts by weight, and the amount of the packing material is 25-45 parts by weight. The gel slug plugging method including simple operation and low requirement for ambient environment; besides, the bridging material, linking material and packing material in the gel plugging slurry form stable structures in the gel, and thereby the gel plugging effect can be improved effectively.

Abstract: The present invention relates to the field of drilling fluids, and discloses a drilling fluid that can inhibit surface hydration of clay and a preparation method of the drilling fluid. The drilling fluid contains water, bentonite, an intercalation inhibitor, a tackifier, a flow pattern regulator, a filtrate reducer, a lubricant, and a weighting agent, wherein, based on 100 parts by weight of water, the content of the bentonite is 2-9 parts by weight, the content of the intercalation inhibitor is 0.3-4 parts by weight, the content of the tackifier is 1-10 parts by weight, the content of the flow pattern regulator is 0.8-7 parts by weight, the content of the filtrate reducer is 1-8 parts by weight, the content of the lubricant is 0.

Abstract: The present invention relates to the field of reagents for oil and gas wells, and discloses a plugging agent for improving bearing capacity and a preparation method of the plugging agent, wherein, the plugging agent contains water, bridging granules, packing granules, and a cementing material, and, based on 100 parts by weight of water, the content of the bridging granules is 3-15 parts by weight, the content of the packing granules is 5-23 parts by weight, and the content of the cementing material is 4-11 parts by weight. The plugging agent in the present invention can improve the bearing capacity of the formation during well plugging, is applicable to shielded temporary plugging against serious leakage loss during extra-deep well drilling, has efficient and quick plugging performance, and is especially applicable to plugging against serious leakage loss in a formation where the well depth is greater than 3,000 m and conventional plugging agents can't attain a satisfactory plugging effect.

Abstract: The present invention relates to the deep-well drilling fluid field, and discloses a high-temperature crosslinking deep-well drilling fluid and a method for preparing the high-temperature crosslinking deep-well drilling fluid. The high-temperature crosslinking deep-well drilling fluid contains water, bentonite, sulfomethylated phenolic resin, sulfonated lignite, halide salt, filtrate reducer, sodium polyacrylate and barite, wherein, based on 100 parts by weight of water, the content of the bentonite is 3.5-5 parts by weight, the content of the sulfomethylated phenolic resin is 6-8 parts by weight, the content of the sulfonated lignite is 6-8 parts by weight, the content of the halide salt is 7.5-12 parts by weight, the content of the filtrate reducer is 0.5-1.2 parts by weight, the content of the sodium polyacrylate is 0.8-1.7 parts by weight, and the content of the barite is 250-300 parts by weight.

Abstract: The present invention relates to the deep-well drilling fluid field, and discloses a deep-well polysulfonate drilling fluid and a method for preparing the deep-well polysulfonate drilling fluid. The drilling fluid contains water, bentonite, sodium carbonate, sulfomethylated phenolic resin, sulfonated lignite, halide salt, filtrate reducer, sodium polyacrylate, sodium bisulfite and barite, wherein, based on 100 parts by weight of water, the content of the bentonite is 3.5-5 parts by weight, the content of the sodium carbonate is 0.15-0.35 parts by weight, the content of the sulfomethylated phenolic resin is 6-8 parts by weight, the content of the sulfonated lignite is 6-8 parts by weight, the content of the halide salt is 7.5-12 parts by weight, the content of the filtrate reducer is 0.5-1.2 parts by weight, the content of the sodium polyacrylate is 0.8-1.

Abstract: The present invention provides a multi-functional hybrid fracturing fluid system, comprising slick water and high viscosity sand carrying fluid, wherein the slick water contains 0.02%˜0.15% of friction-reducing agent by mass percentage, the high viscosity sand carrying fluid contains 0.2%˜0.75% of thickener by mass percentage; the friction-reducing agent and the thickener are the same associative polymer which is a modified natural associative polymer and/or an organic synthetic associative polymer.

Abstract: The present invention relates to the field of well drilling, and particularly to a gel, a plugging method using the same, and a well killing and plugging method using the same. The gel is a water soluble hydrophobic associated polymer copolymerized by hydrophobic monomer and nonionic monomer, or a water soluble hydrophobic associated polymer copolymerized by hydrophobic monomer, nonionic monomer, and alkene salt monomer. The copolymerization method thereof may be a copolymerization post-hydrolysis method or a copolymerization co-hydrolysis method. The leaking stoppage method using the gel comprises: adding 8-18g of gel to 1 kg of water, and feeding the mixture to a leakage layer; and then feeding a spacer fluid. Based on the plugging method using the gel, the well killing and plugging method using the gel further comprises: feeding heavy mud to a well to kill the well cyclically.