川东北地区气体钻进后的钻井液技术及应用

川东北地区大部分采用气体钻进的井段为上部地层,主要岩性为泥页岩,气体钻进后替入水基钻井液,经常发生复杂情况。分析了气体钻进后顶替钻井液初期容易发生井塌、井漏等复杂情况的原因,介绍了解决川东北地区气体钻进后井壁失稳的钻井液技术对策、技术方案及防止井壁失稳的钻井液工艺技术。在七北101井、东升1井现场应用证明,该工艺技术可行,解决了气体钻进后井壁失稳、严重井漏的技术问题。

Drilling Fluid Technology and Its Application in Oil And Gas Wells Drilled with Gas Fluids in Northwestern Sichuan

The formations of the upper intervals of most oil and gas wells in north eastern Sichuan weremudstones/shales. After drilling the upper intervals with gas/air, water base muds were used to drill thelower parts of the holes, leading to a series downhole problems such as hole instability and mud losses. Anintegrated drilling fluid technology dealing with these downhole problems was introduced in this article,based on the diagnosis on the problems, which most often took place immediately after displacing the gas/air with water base muds. The application of the drilling fluid technology in well Beiqi-101 and well Dongsheng-1 proved feasible and successful.