Acid-hydrolyzable residue-free drilling fluid and preparation method thereof

Abstract

An acid-hydrolyzable residue-free drilling fluid includes the following components in parts by weight: 100 parts of water, 0.5-1.5 parts of a pH regulator, 0.5-1.0 parts of a flow pattern regulator, 1.0-4.0 parts of a filtrate reducer, 0-10.0 parts of a temporary plugging agent, 1.0-3.0 parts of an inhibitor and 5.0-200.0 parts of a weighting agent; the pH regulator is a mixture of sodium citrate, magnesium oxide and sodium carbonate; the flow pattern regulator includes at least one of polyethylene oxide and polyethyleneimine; and the filtrate reducer includes one or more selected from the group consisting of waxy starch, waxy physically modified starch and waxy chemically modified starch. The acid-hydrolyzable residue-free drilling fluid overcomes shortcomings of residue and non-degradation of drilling fluids without solid phases or clay phases in the related art, and can be dissolved by an acidic well completion fluid to form a transparent clear solution without suspended matter.

Dependencies are inferred from the claim text.