High temperature-resisting fluid loss agent for drilling fluid and preparation method thereof

Abstract

The invention discloses a high temperature-resisting fluid loss agent for drilling fluid. The high temperature-resisting fluid loss agent is characterized by being prepared from the following components and raw materials in percentage by mass: 10 to 15 percent of abietic acid, 8 to 12 percent of glycerol, 30 to 40 percent of sulfonated bitumen, 10 to 12 percent of cationic starch, 10 to 20 percent of temporary plugging agent, 12 to 14 percent of high temperature stabilizer and 0.5 to 1.0 percent of deoxidant, wherein the cationic starch is prepared from starch tert-amino alkyl ether and quaternary ammonium starch ether; the high temperature stabilizer is prepared from sulfonated phenol-formaldehyde resin and sulfonated lignite resin; the temporary plugging agent is prepared from tert-butyl phenolic curing resin, octyl phenolic curing resin and calcium carbonate. The high-temperature resistance is up to 250 DEG C, no blistering exists, the viscosity effect is low, the compatibility is good, a product contains rigid particles and softening film-forming particles in different size grading, the product directly participate in mud cake forming, a high-strength adsorption film is formed on the surface of the mud cake, the permeability rate of the mud cake is reduced, the quality of the mud cake is improved, and the function of reducing high-temperature high-pressure filter loss is achieved.

Description

technical field [0001] The invention relates to the field of oil and gas well exploitation, in particular to a high-temperature anti-fluid loss agent for drilling fluid and a preparation method thereof. Background technique [0002] At present, China's onshore and offshore oil and gas exploration are extending to deep layers (under 4500m underground), ultra-deep layers (under 6000m underground), and shale gas and other oil and gas fields, such as Sichuan, Xinjiang, South China Sea and other oil regions. During the drilling process, the drilling fluid is in high temperature (220-250°C or even higher temperature), high pressure (greater than 70MPa), high density (greater than 2.0g / cm3) and other conditions, which will easily lead to poor mud cake quality and large fluid loss, etc. technical challenge. Most of the fluid loss control agents in the prior art are polymers, humic acid amines, lignin and asphalt. However, this kind of fluid loss reducer is easy to increase frictio...

AI Technical Summary

Problems solved by technology

However, this kind of fluid loss reducer is easy to increase friction and has a high relative molecular weight. In order to reduce fluid loss in brine drilling fluid and high temperature conditions, it is necessary to increase the amount of addition, which will lead to drilling fluid viscosity. If it is too high, the mud cake is too thick, which will lead to an increase in filtration loss

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