Key Drilling Technologies for the Ultra-Deep Well Manshen 1 in the Tarim Basin

Well Manshen 1 is a pre-exploration well deployed on the Manshen No. 1 fault zone of the Tabei uplift in the Tarim Basin. During the drilling process, this well suffered from both lost circulation and the collapse of Permian basalt. Further, the development of the well was challenged by poor drillability and rapid bit wear in Silurian Tataaiertage Formation, and the slanting and wellbore instability/collapse in Ordovician Santamu Formation. Through technical research, a series of technologies and interventions strategies such as Permian “2X Excellence” drilling, the Silurian vibration reduction and accelerated drilling, and the Ordovician anti-slanting/ collapse drilling were developed, which effectively solved those challenges. The application of hybrid drilling bit+ PDM fast drilling technology successfully penetrating Permian basalt in one trip; the application of polysulfonate drilling fluid system ensuring the safe drilling in Permian strata, and eliminating the downhole failures such as leakage and collapse. Compared with the adjacent wells, the ROP was increased by 265.96%; the customized PDC bit + TorkBuster torque impactor successfully penetrating Silurian strata in one trip, the torque was stable and the stick-slip vibration was weak during the drilling, and the effects of vibration reduction and speed up were clear. The application of pre-bending downhole motor BHA successfully allowed the drillbit to penetrae the Ordovician large dip-angle strata. In this, the anti-slanting effect was obvious; the application of high-performance anti-collapse water-based drilling fluid system safely drilling through the Ordovician hard and brittle mudstone, which achieved a remarkable borehole stabilization effect. This well achieved high-production industrial oil flow drilling oil testing, brought about a major breakthrough in ultra-deep oil and gas exploration of the Tarim Basin, and initially formed the ultra-deep carbonate drilling/completion technologies, which provided technical supports and best practice for the deep oil and gas exploration & development the of Tarim Oilfield.