PLUGGING COMPOSITION FOR LOST-CIRCULATION ZONE ISOLATION DURING WELL DRILLING

摘要

FIELD: oil production industry, particularly plugging compositions for lost-circulation zone isolation during well drilling in salt karst areas or in areas between salt layers hydrodynamically connected one to another.;SUBSTANCE: plugging composition comprises gypsum binding material, magnesium chloride, magnesite caustic powder and water. Above components are taken in the following amounts (% by weight): gypsum binding material - 46.64-56.27, magnesium chloride - 9.15-11.92, magnesite caustic powder - 2.90-10.35, remainder is water.;EFFECT: increased initial time of plugging composition hardening and setting and reduced hardening and setting time of plugging composition mixed with formation water, increased strength of cement stone strength and improved adhesion thereof to salt-bearing rock.;2 ex, 1 tbl