Synthesis of hyperbranched polyquaternium intercalation inhibitor and water-based drilling fluid

Abstract

The invention discloses synthesis of a hyperbranched polyquaternary ammonium salt intercalation inhibitor and a water-based drilling fluid. The hyperbranched polyquaternary ammonium salt intercalation inhibitor is prepared by mixing hyperbranched polyquaternary ammonium salt and water, wherein the mass ratio of the hyperbranched polyquaternary ammonium salt in the drilling fluid is 0.5%-5%. Synthetic raw materials of the hyperbranched polyquaternary ammonium salt are carboxylic acid substances containing multiple amino groups and aniline substances containing multiple double bonds, and an end capping reagent is one of acryloyloxyethyl trimethyl ammonium and methacryloyloxyethyl trimethyl ammonium. The drilling fluid comprises the hyperbranched polyquaternium provided by the invention. The drilling fluid can effectively inhibit shale hydration expansion. The shale intercalation inhibitor prepared from the hyperbranched polyquaternium provided by the invention is non-toxic and harmless and is easier to combine with a clay layer with negative electricity, and the inhibition performance of the shale intercalation inhibitor is obviously improved compared with that of similar intercalation inhibitors.

Description

technical field [0001] The invention relates to the technical field of oil and gas field drilling, in particular to the synthesis of a hyperbranched polyquaternary ammonium salt intercalation inhibitor and a water-based drilling fluid containing the inhibitor. Background technique [0002] Borehole wall instability is one of the problems that seriously affect the efficiency of oil and gas drilling and production. The direct or indirect economic losses caused by hole wall instability, diameter shrinkage, diameter expansion, pipe sticking and even well collapse accidents are as high as billions of dollars every year. At present, 75% of the drilled or drilled formations belong to shale formations, and 90% of wellbore instability problems occur in shale formations. This is due to the strong water sensitivity of shale. When the shale formation encounters water, it will produce severe hydration, resulting in hydration expansion and dispersion of shale, resulting in a decrease in t...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problem of wellbore instability caused by conventional inhibitors being unable to effectively inhibit shale hydration expansion, the present invention provides a synthesis method of hyperbranched polyquaternium intercalation inhibitors, which can effectively inhibit water in shale formations. Reduce the expansion problem, so as to achieve the purpose of stabilizing the borehole wall

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