High temperature and salt resistant polymer fluid loss additive for drilling fluid and preparation method of high temperature and salt resistant polymer fluid loss additive

Abstract

The invention relates to a high temperature and salt resistant polymer fluid loss additive for a drilling fluid and a preparing method of the high temperature and salt resistant polymer fluid loss additive. The fluid loss additive is a copolymer generated during the reaction of alkenyl amide, alkenyl benzene sulfuric acid, alkenyl flavanone and alkenyl sulfuric acid. The preparing method comprises the following steps: (1), weighing the four materials; (2) mixing the alkenyl sulfuric acid liquor with the alkenyl amide, the alkenyl flavanone and the alkenyl benzene sulfuric acid in a reactor, mixing, stirring, and adding nitrogen while discharging oxygen; (3) reacting at the temperature of 30 to 90 DEG C, adding initiating agents (namely, potassium persulfate and sodium hydrosulfite) with the contents of 15 to 30 percent by weight respectively, and reacting for 2 to 12 h so as to obtain a viscous-elastic jelly; and (4) pelletizing the jelly, and drying and crashing at high temperature to obtain the fluid loss additive. At high temperature, the oxydrolysis degree is low, and the action effect between functional groups on a lateral chain and clay particles is remarkable, the quality of a mud cake formed according to the method is better, and the fluid loss effect is favorable in both fresh water and a composite salt water drilling fluid.

Description

technical field

[0001] The invention relates to a salt-resistant drilling fluid fluid loss reducer used for high-temperature and high-pressure formation drilling in the oil drilling process and a preparation method thereof, in particular to a polymer fluid loss reducer and a preparation method thereof. Background technique

[0002] With the increasing demand for oil and gas resources and the depletion of shallow oil and gas resources, more and more attention has been paid to the exploration and development of oil and gas resources in deep formations, and the number of ultra-deep well drilling operations has increased year by year. As the formation depth increases, the formation temperature will also become higher and higher, and during the drilling process, salt formations are often encountered. Therefore, fluid loss control agents suitable for deep wells, high temperature resistance, salt resistance, and calcium and magnesium resistance have become a direction of drilling f...

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