Application and Understanding of Nitrogen Drilling and Completion Technology in Deep Tight Sandstone Gas Reservoirs in the Dibei Block
Targeting the tight sandstone reservoirs of the Ahe Formation in the Dbei Block of the Tarim Oilfield,characterized by dense lithology,high formation pressure,and developed coal seams,the conventional liquid-based drilling and completion technology significantly damages the reservoir.Therefore,nitrogen drilling and completion technology was introduced and field-tested in the well DX1,achieving high production with a daily gas output of 82.39×104 m3 and a daily oil output of 100.8 m3.However,due to the complexity of the formation lithology,severe wellbore collapse,failure of internal blowout prevention tools,and erosion of well control e-quipment occurred during the nitrogen drilling and completion process,limiting the widespread application of this technology in the block.Improvements and optimizations in key processes and equipment,including wellbore structure,bottom hole assembly,wellhead equipment,bleed off ling,internal blowout prevention tools,and ac-companying technological processes,a suitable nitrogen drilling and well completion technology for high-pres-sure,high-yield tight sandstone reservoirs was developed.This technology was field-tested in the well DB104,showing significant results.Compared to the liquid-based drilling and completion methods in the same block,the daily gas production of DB104 well increased by more than 400 times and the daily production increased by 6 times.The wells DX1 and DB104 demonstrate that with proper techniques,equipment,and measures,nitrogen drilling and completion technology can effectively protect the reservoir in high-temperature,high-pressure,deep dense sandstone gas reservoirs in the Dibei Block.This technology provides technical support for efficient explo-ration and development of high-pressure,high-yield,dense sandstone reservoirs in the Tarim Oilfield and across the country.
Dibei Blockhigh-pressure high-yielddeep tight reservoirnitrogen drilling and well completionreservoir protection