High Efficiency Washing Technology of Tailpipe Well in Bohai Oilfield

Tailpipe well is a kind of casing procedure commonly used in Bohai Oilfield. Due to the change of casing size, two kinds of drilling tools and scrapers are required for scraping wells. The internal diameter of bottom drilling tool is small, and the frictional resistance is strong, washing displacement may not be able to meet the minimum return rate requirements for carrying impurities such as cement blocks at the bottom of the well, resulting in unclean well cleaning and affecting later completion operations. Starting from the difficulties existing in the tailpipe well washing in an oil field in Bohai, this paper analyzes and summarizes the factors affecting the tailpipe well washing, and innovatively introduces multi-functional filters and loop path conversion tools used in segmented well washing to achieve the goal of efficient well washing. Finally, a process technology system is established that including the optimization of tailpipe well washing method, well washing column and well washing fluid optimization, which achieves good results in field applications.