Research Progress on Oil-Based Mud Washing Fluid System

The residual oil-based drilling mud on the casing wall is the main factor in blocking the near-wellbore reservoir channel and reducing the wellbore productivity. The well flushing fluid can clean the oil-based drilling fluid on the inner wall of the wellbore casing, improve the wellbore cleaning efficiency, and ensure the oil well's normal production. Therefore, the research status on well-flushing fluids at home and abroad the advantages, disadvantages, and applicability of various cleaning efficiency evaluation methods are investigated and analyzed. Moreover, the cleaning mechanism of well-flushing fluids on oil-based mud is also discussed. The work is intended to provide a basis for innovation and advancing research in developing different oil-based mud and wellbore flushing fluids to meet the needs of varying Well conditions.