High-temperature-resistant and salt-resistant filtrate loss reducer for drilling fluid and preparation method and application of filtrate loss reducer

Abstract

The invention discloses a high-temperature-resistant and salt-resistant filtrate loss reducer for drilling fluid and a preparation method and application of the filtrate loss reducer. The preparation method comprises the following steps that 2-acrylamido-2-methylpropane sulfonic acid and water are added into a reactor and stirred to be fully dissolved; acrylic acid is added into the reactor, then a pH value regulator is added, and the pH value of the mixture in the reactor is regulated to be 7-9; N-isopropylacrylamide and nano-calcium bentonite are added into the reactor and stirred to be uniform; an initiator is added into the reactor, and a reaction is conducted to obtain a reaction product; the obtained reaction product is washed with acetone, filtration is conducted, and then a filtration product is collected; the filtration product is dried in vacuum and then crushed to obtain white powder, that is, the high-temperature-resistant and salt-resistant filtrate loss reducer for the drilling fluid. The filtrate loss reducer prepared through the method is good in performance and temperature-resistant and salt-resistant effect, simple in processing technology and low in development cost.

Description

technical field [0001] The invention relates to the technical field of fluid loss control agents using organic molecules as raw materials. More specifically, it relates to a high-temperature and salt-resistant fluid loss reducer for drilling fluid, a preparation method and application thereof. Background technique [0002] When drilling or completing a well in a formation, various fluids are typically used in the well for a variety of reasons. Common uses of well fluids include: wetting and cooling drill bit cutting surfaces during normal drilling or drill-out (drilling through targeted oil-bearing formations); transport to the surface; control formation fluid pressure to prevent blowout; maintain well stability; suspend solids in the well; minimize fluid loss in the drilling formation and stabilize formations drilled through; fracture the formation near the well, Substituting another fluid for the fluid in the well; cleaning the well; testing the well; transmitting hydrau...

AI Technical Summary

Problems solved by technology

[0005] Although there are many types of fluid loss control agents used in oilfield drilling, there are few products that have good temperature resistance and salt resistance at the same time.

The preparation method of the anti-high temperature and anti-salt fluid loss reducer disclosed in the patent document CN104292387A is: adjust the aqueous solution of 2-acrylamide-2-methylpropanesulfonic acid to 7, and then add acrylamide and diallyl Aqueous solution of dimethyl ammonium chloride, pass nitrogen gas and stir to obtain a mixed solution, add initiator to the mixed solution, let it stand at 35-55°C for 3-7 hours, wash the viscous material repeatedly with ethanol, and dry it High-temperature and salt-resistant fluid loss additives are obtained, but the defect in the preparation method of fluid loss additives in the prior art is that the high-temperature and salt-resistant properties of the fluid loss additive products have certain limitations, and the reaction time Longer, more complex processing technology, expensive

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