Status and prospect of CNOOC’s extended reach well drilling technologies

Extended reach well is an import method to develop offshore oil and gas resources, and it can reduce the construction of production platform and implement progressive exploration and development of oil and gas. In recent years, new progresses have been made in extended reach well drilling technologies for offshore oil in China. In this paper, the current situations of the optimization design and quantitative evaluation of borehole trajectory design of extended reach well, the drilling fluid and oily cuttings disposal technology, the efficient hole cleaning technology and monitoring method, the friction and torque reduction technology for safe drilling, and the efficient casing running technology were illustrated, and the technical progresses of pseudo-catenary trajectory design, deep solid control disposal of offshore cuttings, hole cleaning monitoring method, friction and torque reduction tool, string running supporting tool were summarized. Then, the future needs and challenges to extended reach well were predicted, and it was suggested to continuously strengthen the technological innovation and research of open-hole extension capacity, hydraulic extension capacity and mechanical extension capacity of extended reach well, so as to further meet the stricter requirements of offshore marginal oil and gas field development and secondary old oilfield adjustment for extended reach well technologies.