3results about How to "Good settlement stability" patented technology

This invention discloses a high-temperature resistant, high-density water-based drilling fluid for ultra-deep wells and its preparation method, belonging to the field of oil and gas drilling technology. The drilling fluid is composed of the following components in parts by weight: 100 parts water, 2-5 parts high-temperature resistant modified clay, 150-280 parts composite weighting agent, 8-15 parts high-temperature resistant polymer filtration loss reducer, 3-8 parts core-shell type high-temperature resistant flow modifier, 4-10 parts nano-composite plugging agent, and 2-5 parts high-temperature stabilizer. This invention effectively solves the technical problems of rheological runaway, increased filtration loss, and barite sedimentation in ultra-deep well high-density water-based drilling fluids under high-temperature conditions above 220℃ by utilizing the high-temperature expansion-disintegration mechanism of the core-shell type flow modifier, nano- to micron-level multi-stage plugging, and the close packing of spherical and irregular weighting materials. It exhibits temperature resistance up to 220℃ and a density of 2.80 g / cm³. 3 It has the advantages of low filtration loss under high temperature and high pressure and good sedimentation stability.

The application provides a high-density water-based completion fluid resistant to carbon dioxide pollution, which is composed of the following components in mass fraction: 100 parts of bentonite slurry, 0.4-0.6 parts of sodium hydroxide, 5-10 parts of filtrate reducer A, 10-15 parts of filtrate reducer B, 2-3 parts of acid gas complexing agent and weighting agent. 3 The density of the completion fluid is 2.00g / cm 3 ~2.50g / cm The completion fluid has good sedimentation stability and rheological property after being kept at 150 DEG C for 10 days, and can meet the needs of field construction; meanwhile, the completion fluid is resistant to temperature of 150 DEG C-170 DEG C, and solves the problem that the performance of the existing high-density water-based completion fluid is out of control after being polluted by carbon dioxide under high-temperature conditions.

The application relates to a preparation method of an ultra-high-temperature fluid loss additive for well cementing, and belongs to the technical field of oilfield chemicals. After surface modification of palygorskite by a silane coupling agent, the surface polymerization sites of the palygorskite are obtained, so as to participate in a polymerization reaction. N,N-dimethyl acrylamide and other non-ionic water-soluble monomers, 2-acrylamide-2-methylpropanesulfonic acid, itaconic acid, sodium styrene sulfonate and other anionic water-soluble monomers, and vinyl pyrrolidone, sodium p-styrene sulfonate and other rigid monomers are used as polymerization raw materials to synthesize polymer grafted palygorskite. The fluid loss additive has excellent temperature resistance and salt resistance, has excellent fluid loss performance in a high-temperature and ultra-high-temperature environment, the fluid loss amount is less than 50 mL at 240 DEG C, has no obvious influence on other basic performances of cement slurry, can effectively improve the suspension stability of the cement slurry at high temperature, and is suitable for being used as a fluid loss additive for cement slurry under harsh conditions.