New progress of drilling and completion technologies for ultra-deep wells in the Sichuan-Chongqing area

PetroChina’s exploration and development in the Sichuan-Chongqing area has moved deeper from the Permian-Triassic to the Lower Permian-Sinian and regionally extends to the periphery of Central Sichuan paleo-uplift, the Lower Permian of western Sichuan and the Cambrian of eastern Sichuan, where the geological conditions are more complicated. Multiple pressure systems of ultra-deep well, poor drillability, ultra-high pressure, ultra-high temperature and high sulfur content bring huge challenges to well drilling and completion engineering. An ultra-deep well drilling and completion technology integrating casing program optimization, bit customization, high-quality drilling and completion fluid, deep horizontal well drilling, precisely managed pressure drilling and special coring is formed by performing technical researches. It provides the powerful technical support for the fast transformation of the Longwangmiao Formation resources in the Anyue Gas Field and the significant discovery of Permian and Devonian resources and speeds up the exploration and development process of deep oil and gas reservoirs in the Sichuan-Chongqing area.