Abstract: Drilling and completion operations in the extended-reach wells of the Yangshuiwu buried hill reservoir are facing technical challenges, such as high friction torque and bottom-hole temperature, difficult well trajectory control and small gaps in cementing, and low ROP in formations of mudstone, conglomerate, and basalt. In light of the formation characteristics, through theoretical analysis and simulation, the casing program and well trajectory were optimized, the well-trajectory control mode and the drilling fluid system were upgraded, and the performance of drilling fluid was improved. In addition, the technical measures for increasing ROP and cementing were introduced. As a result, a system of key drilling and completion technologies of extended-reach wells in the Yangshuiwu buried hill reservoir of the Huabei Oilfield was developed. The field tests of this technical system confirmed safe and smooth drilling and completion in Well T5X and Well T101X. Compared with the adjacent wells without the support of this system, the two test wells had a ROP increase of 27.4% and the drilling cycle decrease of 19.7%. The research and field tests demonstrated that this system can solve the technical difficulties encountered in the drilling and completion of extended-reach wells in the Yangshuiwu buried hill reservoir of the Huabei Oilfield, and can meet the requirements for safe and efficient drilling and completion in this area.