Profile Control for Wasted Drilling Fluid Recycling in ZC Oilfield of the Subei Basin

Due to emerging channeling-paths inside the reservoir and ineffective and inefficient circulation of injected water along the paths in the late high water cut development stage of ZC Oilfield,the water-to-oil ratio may rise sharply,resulting in a rapid increase in development costs and an obvious decline in economic benefits.Incorporating the principles of profile control and water plugging,a feasibility study on the profile control system of wasted drilling fluid recycling was conducted through lab tests,in which the sealing effect of this system was changed by stirring and pH value adjustment.Finally,the profile control system of wasted drilling fluid recycling was determined.Field tests showed that this process achieves a good performance in water plugging and water absorption structure modification,and also accomplishes wasted drilling fluid recycling.The system could prevent pollution from wasted drilling fluid and reduce profile control costs.This technology would provide technical support for the low-cost profile control of high water cut oilfields.