Oil Base Mud

Dennis Energy Services, Inc.

SITUATION	PRODUCTS	LBS/BBL	PILL	SWEEP FREQUENCY	NOTES
PREVENTIVE SWEEPS	MCT-500 MCT-1000	7 P.P.B.	15 – 25 bbls	6 – 8 hours	w Dilute with diesel or mud as required. w Pump sweep every 6 - 8 hours, and additional as each potential problem sand is drilled. w Continue sweeps as long as underblalaced sands are exposed. w Add wetting agent per mud company rep. directions.
SEEPAGE SWEEPS	MCT-500 MCT-1000	5 P.P.B. 10 P.P.B.	50 bbls	4 hours or 100’ of new hole drilled	w Pump 25 – 50 bbls sweeps (calculated to cover 500’ of hole). w Pump sweep every 4 hours or 100’ of hole drilled. w Adjust frequency for severity of problems. w Continue sweeping program as long as underbalanced sands are exposed. w Maintain pH above 9.5.
LOST CIRCULATION “PARTIAL RETURNS”	MCT-500 MCT-1000	20 P.P.B. 16 P.P.B.	50 bbls	Pump sweeps as conditions dictate 2 – 3 Sweeps may be required to control losses	w Mix DESI SEAL Medium first, then add the fine. w Dilute with mud or water as required. w Pump sweeps at reduced speed. w Adjust concentration and frequency as conditions dictate. w Spot pill in place should conditions worsen.
LOST CIRCULATION TOTAL LOSS & LESS THAN 50% RETURNS	MCT-500 MCT-1000	32 P.P.B. 13 P.P.B.	50 bbls	Spot pills Follow up with sweeping program as required.	w Mix Medium first, then add the fine. w Dilute with mud or water as required. w Pump pill at reduced pump speed. w Spot pill at suspected loss zone. w POOH (or to last casing) Allow hole to heal. w Stage in hole after regaining circulation. w Establish regular sweeping program to TD.