Journal of Chemistry and Chemical Research

The geological lithology of the lower strata of the Shunbei Block, Xinjiang, is gray and yellowish gray micrite limestone. The Ordovician carbonate reservoir is characterized by the development of corrosion holes and fractures, often resulting in downhole complex situations such as well bed, lost circulation, and kick. Collapse and leakage in the same layer, narrow density window, and high bottom hole temperature make the polysulfonated potassium salt based mud unable to meet downhole requirements. The problem of oil based mud plugging has been solved by adopting prevention first, supplemented by plugging measures, and combining rigid and flexible plugging materials. It provides reference significance for the occurrence of lost circulation during construction in this block.

oil-based drilling fluid; Shunbei Block; Lost circulation; Plugging technology