Abstract: During the“14th Five-Year Plan”period, China National Petroleum Corporation (CNPC) has achieved a series of breakthroughs in drilling and completion technologies, addressing the development needs of deep layers, deep-sea, and unconventional resources, as well as mature oil and gas fields. To address challenges such as extreme high temperature and pressure in ultra-deep wells and wellbore instability, a 12 000-meter and a 15 000-meter automated drilling rig were developed. These rigs were equipped with 70 MPa high-pressure quintuple-cylinder drilling pumps and have mechanized approximately 80% of the heavy manual labor on the drill floor. By adopting a combination of expandable tubular open-hole plugging and non-standard casing, a complex eight-spud and eight-section completion casing program was achieved, effectively addressing the coexistence of multiple pressure systems. Environmentally friendly water-based drilling fluids resistant to 240 ℃ were successfully developed, along with film-forming cementing hydrophobic drilling fluids whose performance rivaled that of oil-based drilling fluids and oil-based drilling fluids resistant to 260 ℃. High-end PDC drill bits and positive displacement motors resistant to 200 ℃ were developed, and their combined use has significantly increased the rate of penetration. Near-bit geosteering systems and the CG-STEER rotary geosteering system were developed to improve reservoir identification accuracy and achieve precise steering. Systems utilizing multi-source data for accident warning and dynamic simulation of drilling tool conditions were developed, effectively reducing drilling risks. A cement slurry system resistant to 240 ℃, with temperature differences exceeding 100 ℃ was established, enhancing cementing quality and ensuring wellbore integrity. Currently, China’s petroleum drilling and completion technologies face three major challenges: the casing program for ultra-deep wells is constrained by the limitations of existing casings, making it difficult to cope with complex pressure systems; temperatures exceeding 240 ℃ lead to increased failure rates of downhole tools, highlighting the bottleneck in heat resistance of electronic components; ultra-long horizontal sections present engineering difficulties such as high friction and torque, as well as challenges in casing running. In the future, efforts should focus on strengthening fundamental research in areas such as rock mechanics, overcoming the bottlenecks in developing 260 ℃ working fluid systems and 240 ℃ bottom hole assembly, advancing high-build-rate rotary steering systems and intelligent geological navigation technologies, deepening the application of AI and large-scale models in smart drilling rigs and adaptive control systems, and continuously expanding the depth boundaries of oil and gas exploration and development through multi-technology integration and innovation. This will provide technological support for safeguarding national energy security.