METHOD OF TREATING SHALE AND CLAY IN HYDROCARBON FORMATION DRILLING

摘要

Swelling and migration of subterranean clay is inhibited during drilling forand stimulation of the production of hydrocarbon fluids, and preparationtherefor, by treating said formations with a copolymer of about 5 % to about50 % of an anionic monomer such as acrylic acid, methacrylic acid, or 2-acrylamido-2-methyl propane sulfonic acid and the balance a cationic monomerselected from dimethyl diallyl ammonium chloride, or acryloxy or methacryloxyethyl, propyl or 3-methyl butyl trimetyl ammonium chlorides or methosulfates.Permeability damage to the formation is reduced in the presence of thecopolymer; it is particularly effective in spite of the presence of a foamingagent.