Key Technologies for the Drilling of Ultra-Deep Horizontal Well Shunbei 56X

Well Shunbei 56X is a major ultra-deep wildcat well for the deployment of the Shunbei V Strip. While drilling this well, loss of circulation happened easily in the Permian and Silurian systems, with attendant technical problems, such as the poor stability of well walls in Ordovician fractured formations, well deviation in Ordovician Sangtamu Formation, difficulty in controlling the well trajectory, and gas kicks of fracture zones drilled in reservoirs, etc. Therefore, to remedy the geological characteristics tied to the Permian, Silurian, and Ordovician formations, an anti-leakage and plugging drilling fluid and the high-temperature oil-based drilling fluid with strong plugging properties were selected, and corresponding maintenance and treatment measures were formulated. It could effectively prevent loss of circulation in Permian and Silurian systems and ensure the well wall stability in the Ordovician system. The technology of “high-torque positive displacement drill (PDM) + vertical drilling system” was applied to achieve deviation prevention and fast drilling of the vertical sections of the well. Moreover, with a combination of well-path optimization, fast regulation of tool faces, matching technology of high-temperature measurement while drilling (MWD), and well trajectory design, the trajectory of the well was highly consistent with the well-path to achieve accurate target hits. The technology of “slightly overbalanced density design + simple managed pressure drilling” was utilized to solve the gas kick problem of fracture zones drilled in reservoirs. During the drilling of Well Shunbei 56X, no well control risks were identified, and targets were accurately hit. The well was smoothly drilled to the depth of 9300.00 m (a vertical depth of 8087.94 m),which makes it the deepest horizontal well in China and the deepest onshore horizontal well in Asia so far. The safe completion of this well shows that China is capable of drilling ultra-deep horizontal wells, and can provide a technical support for for exploration and development of ultra-deep Shunbei Oil & Gas Field.