Application of a Cement Spacer as a LCM Pill During Drilling Operations to Overcome Lost Circulation and Regain Well Control: A Case History in a Hostile Environment in the Middle East

Abstract

Loss of circulation while drilling can create a multitude of problems during the well construction stage ranging from costly loss of drilling fluid and dry drilling up to well control issues leading to underground and surface blowout. Careful selection of casing depths to effectively isolate formations with varying pressure gradients from each other is essential for the integrity of the well and in consequence the safety and environment. Despite every care being taken in selecting casing points and drilling fluids that should keep the well in balance while avoiding overburden of the formation fracture pressure, losses can still occur suddenly and aggressively. In depleted carbonate reservoirs in the Middle East losses are a common occurrence which the majority of times are grueling to control through conventional methods. This paper discusses the ingenious application of an all-natural polymer based cement spacer including lost circulation material that was successfully applied in a hostile gas field in the Middle East. These wells can recurrently present abnormal pressure, which often leads to a formation breakdown while trying to provide well control due to the heavy mud weights utilized. By maintaining full circulation it was possible to ensure the well remained static, thus achieving zonal isolation and completing the well.