Inhibitive water-based drilling fluid system and method for drilling sands and other water-sensitive formations

摘要

An inhibitive water-based polymer mud system and method for using the system in drilling and in stabilizing wellbores is disclosed for use in water sensitive formations as an alternative to oil-based muds. The system comprises a non-ionic low molecular weight polyacrylamide in combination with a non-ionic high molecular weight polyacrylamide, preferably long chain alcohol and poly anionic cellulose.