气藏提高采收率理念、技术划代及现场实践OA

Starting from the first principle thinking,this study systematically reviews the development mechanisms of gas reservoirs and proposes the development concept of"full lifecycle enhanced gas recovery(EGR)".Following the principles of scientificity,practicality and comparability,a generational classification system for EGR technologies is established.The research indicates that the properties of natural gas dictate a development mechanism primarily driven by pressure depletion to release the elastic expansion energy of gas.This leads to a development model centered on primary depletion,supplemented by limited adjustments in late stages.Early development essentially lies in well pattern optimization and risk pre-control,while late development focuses on targeted local adjustments and integrated collaborative control.Primary gas recovery,relying on natural energy depletion,achieves a recovery factor of 25％-55％.Secondary gas recovery,through active regulation of the reservoir pressure field via techniques like blockage removal,and injection-production optimization,can enhance the recovery factor by 10-15 percentage points.Tertiary gas recovery,employing multiple mechanisms to alter the reservoir's physical and chemical fields synergistically,offers a potential further increase of 5-10 percentage points.Currently,primary recovery technologies are mature and well-established.Synergistic optimization of well patterns and fracture networks enables effective production from gas-drive reservoirs,while optimized development strategies facilitate orderly production from water-drive gas reservoirs.Secondary recovery technologies,in the field pilot stage currently,adopt active measures like enhanced water drainage,water shutoff,and gas injection to effectively control water influx and release trapped gas.Tertiary recovery remains largely in the laboratory or pilot test stage.Future efforts should focus on cross-generational technologies,such as"primary+secondary"and"primary+tertiary"combinations,to continuously improve recovery factors throughout the full lifecycle of gas reservoirs.