METHOD FOR IMPROVING WALL-FORMING PROPERTY OF DRILLING MUD

摘要

PROBLEM TO BE SOLVED: To effectively recycle a deteriorated drilling mud without carrying out disposal of the deteriorated drilling mud. SOLUTION: This method for improving wall-forming properties of drilling mud comprises adding a mud film-forming agent for the drilling mud consisting essentially of (x) a copolymer comprising (a) an unsaturated carboxylic acid and/or its salt and (b) a monoester of (b1) an unsaturated carboxylic acid and (b2) a hydroxy group-containing compound represented by R(OA)nOH (R denotes hydrogen or a 1-12C hydrocarbon group; A denotes a 2-4C alkylene group; and n denotes an integer of 1-100) as constituent units to the deteriorated drilling mud produced by a mud drilling method such as an underground continuous wall making technique or a mud water shielding technique in a method for improving the wall-forming properties of the drilling mud.