Chen Z.,Room 518 of Beichen Shidai Building |
Li D.,Room 518 of Beichen Shidai Building |
Liu S.,Room 518 of Beichen Shidai Building |
Lin Y.,Room 518 of Beichen Shidai Building
Drilling Fluid and Completion Fluid | Year: 2015
Depleted fractured Ordovician carbonate formations in Tahe Oilfield were buried at 6000 m, with formation temperature of about 130℃. When lost circulation occurred, mud circulation can be re-gained with bottom hole pressure exceeding 10 MPa. These fractured formations had high channel connectivity and high salinity formation water. A downhole crosslinking solidification technology was developed to deal with lost circulation in these formations. In laboratory experiment, the crosslinking gelling agent SF-1 had its viscosity soared to above 10000 mPa·s at high temperature (130℃) and high calcium environment, and stayed in place long enough for the mud loss to be stopped. HDL-1, a lost circulation material followed SF-1 reacted with SF-1 in the hole to form a dense plug being able to stand pressures up to 15 MPa, ensuring the efficiency of lost circulation control. This technology was successfully applied in the Well TH12179CH in Tahe Oilfield, where severe lost circulation always occurred. ©, 2014, North China Petroleum Administration Drilling Technology Research Institute. All right reserved.