The reporter learned from CNOOC Tianjin branch that recently, a development evaluation well in Bozhong 19-6 condensate field of Bohai oilfield successfully completed all drilling operations, and the completed drilling depth reached 5813 meters, setting a new record for the well depth of Bohai oilfield again. The well overcame technical problems such as high temperature and high pressure, lost circulation and high torque, and successfully completed drilling in 60 days, accumulating valuable experience for the follow-up high-quality drilling and completion of Bozhong 19-6 condensate gas field.
Bohai oilfield is the largest crude oil production base in China, and Bozhong 19-6 condensate field is the first 100 billion m3 gas field discovered in eastern China so far. As the first deep well in Bohai oilfield, the well project faced many technical problems at the beginning of its establishment. First, the “12.25 inch well section” could not bypass the fault, and the project team should install the first “safety lock” for “lost circulation”; Secondly, the “8.5-inch well section” will encounter abnormal high pressure, so “well control” has become the top priority; The drilling torque of “5-7 / 8 inch well section” is also close to the upper limit of drilling equipment, and coping with “drilling tool fatigue” has become the main risk point. In addition, the high formation temperature also puts forward a severe test for directional well tools and drilling fluid.
In the face of risks and challenges, on-site operators continue to explore new ideas, new management modes and new production technologies, deeply tap engineering risks and scientifically optimize operation schemes. In the operation preparation stage, the operation scheme was repeatedly refined, and the operation scheme was finally finalized after several seminars and scheme review meetings. After the operation starts, the elite and strong generals are selected on site to form a critical team, and the established operation scheme is carefully implemented with the support of the land expert group and the data center.
During drilling, the project team adopts “one well one strategy” and “one section one strategy” to deal with various risks in a directional manner, and adopts the most reasonable solution for engineering operations in different well sections. Under the careful deployment of the project team, various operations on site were closely connected, and finally various well section operation tasks were successfully completed. The construction period was saved for 13 days, and the production operation tasks were completed with high quality and efficiency.