The Successful Application of Expansion Tube Technology in the Bongor Basin of Chad

The Bongor is the main basin for increasing storage and production in the CNPC Chad. With the continuous deepening of development, underground safety operations face the following problems: the inability to effectively seal the gas layer in the overlying strata of the basement, the high risk of secondary completion of the basement gas injection well, and the poor stability of the wellbore in the M group shale formation. In response to the bottleneck problems faced by underground operations, geological, drilling, logging, and other data were analyzed and sorted. Based on the expansion tube technology, the safety sealing technology for high-pressure gas cap in basement, secondary completion technology for basement gas injection wells, and openhole sealing technology for expansion tubes were optimized and formed. They were successfully applied for the first time in the Bongor Basin, achieving a daily gas injection volume of 2000 Nm3, shortening the construction cycle, improving wellbore quality, and reducing complex underground risks, Subsequently, it will be widely promoted and applied as a mature technology, supporting the efficient development of the Bongor Basin. At the same time, the expansion tube technology has a demonstration effect on the development of similar oil fields due to its good practical functions and application value [1–6].