Development and Application of BH-OMP Oil-Washing Spacer

In the drilling process of shale oil horizontal Wells in Dagang Oilfield, the use of oil-based drilling fluid solves the problems of high friction and torque and the difficulty of sliding drilling, but it causes the difficulties of displacement and cleaning in the subsequent construction, especially the displacement and wall washing problems of “big belly” section caused by some complex Wells in the drilling process. In view of the problems that oil-based drilling fluid is prone to produce oil-wet adhesive layer on casing surface and well wall surface and filter cake is difficult to be washed clean with conventional spacer, the development and systematic evaluation of core additives were carried out, and a widely used oil-washing spacer BH-OMP was formed. Through systematic indoor evaluation process and standardized field preparation technology, the stable performance of the spacer before entering the well is ensured. The spacer has been applied well in 20 shale oil and gas Wells and tight oil and gas Wells, and the flushing efficiency has reached more than 98%. It has good stability and no settlement after placing for a week. Also it can effectively isolate cement slurry and oil-based drilling fluid and will not cause ultra-slow coagulation of cement slurry. The research and application show that BH-OMP has a good scouring ability, which provides a favorable barrier for cementing operations and ensures cement to form a strong bond and seal effect on the annulus and casing wall.