Technical Challenges and Solutions for Deep High-Temperature Drilling and Completion in Xinhua Oilfield

Technical difficulties including the widespread leakage-prone special lithologies, poor drillability of deeply buried rocks, insufficient thermal resistance of directional tools due to high temperatures, and instability of high-temperature drilling fluids, and inadequate thermal resistance of conventional cement slurry systems in Xinhua Oilfield. This study conducted integrated geology-engineering optimization and iterative innovation of key technologies, establishing a systematic technical framework for deep high-temperature drilling and completion. The core achievements are as follows: Conducted an evaluation of the distribution of special lithology in Xinhua Oilfield and the risk of lost circulation. By optimizing the wellbore structure progressively, large-diameter well sections were reduced, accelerating the drilling process. Carried out high-temperature drilling fluid experimental evaluations and selected treatment agents resistant to 180 ℃, enhancing the thermal stability of the drilling fluid and wellbore stability. Developed a drillability prediction method based on logging data to predict the drillability of the second section of the reservoir. This guided the selection of high-abrasion-resistant PDC bits, improving single-run footage and rate of penetration (ROP). Through the study of heat exchange mechanisms, surface cooling equipment was installed for horizontal wells, ensuring the normal operation of directional tools in high-temperature environments and facilitating smooth horizontal drilling. Evaluated and optimized high-temperature cementing thermal stabilizers and gas migration prevention agents, and optimized the dual-density, dual-gelation cement slurry structure, improving cementing quality. Through technological innovation and engineering practice, five wells were successfully completed with an average depth of 5228 m, an average drilling cycle of 42.96 days, and an average ROP of 13.06 m/h, achieving a 17.66% improvement over previous drilling performance.