Drilling of a large diameter geological survey well （Well Chuanmudi-2） in Muchuan county of Sichuan province

Abstract:

The large-diameter shale gas geological survey well （Well Chuanmudi-2） is located in the core of the Jianquan-Longhua synclinorium of the Wuzhishan-Tiangongtang structural belt in Southwestern Sichuan Basin with the design depth of 2500 m and the completion depth 2406.00 m. The drilling purpose is to explore continental shale gas in Xujiahe Formation and conventional gas in Leikoupo Formation. This paper introduces the drilling operations of Well Chuanmudi-2， whereby the application research on high-efficiency speed compound drilling， complex formation drilling fluid and casing cementing technology were carried out for the collapse prone mudstone of Jurassic and the poor drillability sandstone of Triassic. Through the research， the difficulty of casing cementing in the collapse section was resolved， drilling efficiency was improved， a qualified well for formation gas bearing test was built， the physical data such as core， cuttings and other were obtained， the stratigraphic sequence of the well area were identified， and the oil and gas display of layer 37 of Triassic Xujiahe Formation and Leikoupo Formation were hit； thus， achieving the drilling purpose， discovering oil & gas， and laying the foundation for shale gas geological investigation and evaluation which has a great significance to consolidate the poverty alleviation achievements in Wumeng Mountain area.