Abstract: The digitization and intelligentization of oil and gas well engineering are of great significance for increasing the productivity of oil and gas wells, reducing operation and drilling costs, as well as improving the health, safety, and environment (HSE) management level. During the Thirteenth Five-Year Plan period, CNOOC has completed its overall layout for the digitization and intelligentization of oil and gas well engineering through theoretical innovation and scientific research. As a result, preliminary achievements have been made in intelligentized operation, collaborative design, and refined management. This paper presents the achievements regarding the digitization and intelligentization of CNOOC’s oil and gas well engineering in detail, including eDrilling system, big data analysis system of drilling parameters, downhole drilling parameter measurement and short signal transmission system, early overflow monitoring system for deepwater drilling, downhole fiber optic monitoring system, drilling and completion integrated design platform, drilling and completion data submission system, information display system, and data analysis system, etc. To address information islands and the shortage of inter-disciplinary talents in intelligentization, the paper points out the necessity of adhering to the philosophy of "making them work for us instead of just being owned by us" while dealing with technologies in digitization, and actively seeks for deep strategic cooperation in the field of oil and gas well engineering with corporations specialized in advanced internet and intelligentization in China and other countries. In addition, it emphasizes independent innovation capabilities and bringing together "enterprises, universities, research institutes, and end-users" to promote the steady improvement of the research and application in regard to the digitization and intelligentization of CNOOC’s oil and gas well engineering so as to boost the high-quality development of the offshore oil industry in China.