Method for enhancing high-temperature stability of polymer drilling fluid

Abstract

The invention discloses a method for enhancing high-temperature stability of a polymer drilling fluid. On the basis of the existing polymer drilling fluid formula and its mass percent, 0.3-1.0 wt% ofa high temperature stabilizer, 0.3-0.5 wt% of a deoxidant and 0.3-0.5 wt% of a bactericide are added to maintain high-temperature rheological property and filtration and wall-building properties of the polymer drilling fluid. The specific addition method is as follows: after the preparation of the polymer drilling fluid, the high temperature stabilizer and the bactericide are firstly added, and the deoxidant is added finally; during the maintenance treatment, the three treating agents are added in proportion, and the deoxidant is finally added. By the method, the problem of failure of the polymer treating agent in chain-scission degradation at the high-temperature condition can be alleviated, the rheological property of the polymer treating agent is remained relatively stable, and downholecomplexity is prevented; and the technical bottleneck that properties of the drilling fluid are maintained by continuously replenishing the polymer treating agent at high temperature is reduced, andthe effect of decreasing cost and increasing benefit is achieved.

Description

technical field [0001] The invention relates to the oil and gas drilling industry, in particular to a method for improving the high-temperature stability of polymer drilling fluid. Background technique [0002] Polymer drilling fluid has the advantages of good inhibition, low toxicity, easy degradation, and environmental friendliness, and has broad application prospects. However, polymer treatment agents are easy to degrade and fail under high temperature and other conditions, and usually need to continuously replenish materials to meet the performance indicators of drilling fluids. In addition, the viscosity and shear force of polymer drilling fluids decrease at high temperatures, and sometimes even fail to meet the functions of suspending weighting agents and carrying cuttings, resulting in downhole complications. The current solution is to additionally develop the corresponding higher temperature resistant polymer treatment agent. [0003] The publication number is 1017...

AI Technical Summary

Problems solved by technology

[0004] However, the prior art represented by the above-mentioned patent documents only adds high-temperature stabilizers when used in polymer drilling fluids, and the effect is not obvious in actual use.