METHOD FOR DISPERSING AQUEOUS BASED DRILLING FLUID FOR DRILLING SUBTERRANEAN BOREHOLES

摘要

An inhibitive water-based polymer mud system and method for using the system in drilling and in stabilizing wellbores for use in water sensitive formations as an alternative to oil-based muds or water-based muds comprising ferro-chrome lignosulfonates. The system comprises a fresh water or salt water base thinned or dispersed with a sulfonated acrylic copolymer having a hybrid/graft lignosulfonate multipolymer structure containing carboxylate and sulfonate functional groups with synthetic polymer side chains covalently linked to a base lignosulfonate material, having a molecular weight in the range of about 1,000 to about 15,000, and having a high anionic charge density.