Comprehensive Leakage Control Technology for Shale Gas Wells in the Western Margin Thrust Zone of the Ordos Basin

There are natural fractures at the interface of deep shale formations in the western edge thrust zone of the Ordos Basin, and multiple sets of weak pressure bearing layers coexist in the long open hole section, resulting in weak pressure bearing capacity and frequent well leaks during drilling, which seriously restricts drilling speed and efficiency. To this end, the technology of pressure retaining wall while drilling was studied to improve the pressure bearing capacity of weak layers in the open hole wellbore section; Using long naked eye leakage layer precise positioning technology to achieve accurate positioning of the leakage layer; We have developed acid soluble high filtration plugging working fluid, which is highly effective in plugging malignant leaks caused by fractures, greatly improving drilling efficiency, and forming a key technology for leak prevention and plugging in the western edge thrust zone of the Ordos Basin. This technology has been applied on site in 14 shale gas wells in the western edge of the Ordos Basin thrust zone, reducing the special plugging time by 55.25% and shortening the drilling cycle by 15.5 days. The comprehensive leak control technology in the western margin thrust zone of the Ordos Basin provides technical support for the safe and efficient development of unconventional oil and gas wells in the Ordos Basin.