Full-cycle enhancing condensate recovery-underground gas storage by integrating cyclic gas flooding and storage from gas condensate reservoirs

Underground gas storage (UGS) is efficient in large-scale natural gas storage and peak regulation. However, UGS operation based on gas -condensate reservoirs are challenging due to complicated phase behavior and multiphase flow considering trapped condensate. This paper presents a method for full -cycle enhancing condensate oil recovery (EOR)-UGS by integrating cyclic gas flooding and storage from gas -condensate reservoirs. Full -cycle EOR-UGS is defined by four stages, including primary depletion, cyclic gas flooding, collaborative gas production and UGS operation. The EOR mechanisms of each stage are analyzed by experiments and simulation. Cyclic gas flooding can reduce drop out of condensate. The reasonable volume of cyclic gas flooding is 0.5 HCPV, enhancing condensate recovery factor by 42.8%. During the collaborative stage, gas injection can effectively evaporate and drive the condensate towards production wells. After five collaborative cycles, the condensate recovery factor is further enhanced by 21.8% and gas storage capacity can be increased more than 30%. Finally, optimal full -cycle EOR-UGS schemes can enhance condensate recovery factor by 69.92%. Compared with gas flooding to 1.5 HCPV followed by constructing UGS, the full -cycle EOR-UGS integration can improve condensate recovery factor by 7.37%. This work provides a new idea for UGS construction and operation based on gas -condensate reservoirs.