What percentage of drilling fluid is lost down the core holes?
Based on Santos’ drilling operations in the Gunnedah Basin so far, average drilling fluid loss has been approximately 6% of make-up volume. The intention is not to lose drilling fluids, as they are the primary means of controlling the core hold. As soon as fluid loss is detected, a loss circulation material (LCM) is fed into the hold with the drilling fluid. LCM is made of cellulose material and looks like sawdust. It prevents fluid loss by blocking the pores in the host rock with cellulose particles. In cases where LCM does not work, the hole is completely sealed with a cement plug which is re-drilled.
Based on Santos’ drilling operations in the Gunnedah Basin so far, average drilling fluid loss has been approximately 6% of make-up volume. The intention is not to lose drilling fluids, as they are the primary means of controlling the core hole. As soon as fluid loss is detected, a loss circulation material (LCM) is fed into the hole with the drilling fluid. LCM is made of cellulose material and looks like sawdust. It prevents fluid loss by blocking the pores in the host rock with cellulose particles. In cases where LCM does not work, the hole is completely sealed with a cement plug which is re-drilled.
