PROCESS AND COMPOSITION FOR DRILLING SHALE FORMATION IN SEA WATER

摘要

PROCESS AND COMPOSITION FOR DRILLING SHALE FORMATION IN SEA WATER A process and composition for drilling a well through shale formation in sea water with an aqueous drilling mud comprising a clay - sea water slurry containing a potassium salt of lignosulfonate. The lignosulfonate is prepared by reaction of potassium hydroxide or a salt of sulfurous acid with spent sulfite liquor at elevated temperatures. A particularly effective drilling composition also contains hydroxy acids and up to 4% based on total solids content of the lignosulfonate, of an iron complex.