Summary: Effect of overbalance pressure on formation damage
S.Z. Jilani a,b
, H. Menouar a,*, A.A. Al-Majed a,b
, M.A. Khan c
Center for Petroleum and Minerals, The Research Institute, King Fahd University of Petroleum and Minerals, Mail Box # 2002,
Dhahran 31261, Saudi Arabia
Department of Petroleum Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
Center for Applied Physical Sciences, The Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
Received 31 July 2001; accepted 5 June 2002
Experiments were conducted to investigate the influence of overbalance pressure on formation damage during drilling
operations. An innovative ultrasonic method was employed to measure mud invasion depth. It was observed that mud invasion
depth decreases with increasing overbalance pressure until it reaches a critical pressure. Beyond that, invasion depth increases
with overbalance pressure. The above phenomenon reflects a strong physical relationship between overbalance pressure and
mud fines and filtrate invasion depth.
D 2002 Elsevier Science B.V. All rights reserved.
Keywords: Formation damage; Mud invasion depth; Horizontal wells; Overbalance pressure; Nondestructive evaluation