Key technologies and development directions of underground gas storage facilities for complex hydrocarbon reservoirs

Underground gas storage （UGS） facilities are recognized as important infrastructures for ensuring the peak shaving， emergency supply， and strategic reserves of natural gas. SINOPEC commenced constructing UGC facilities during the 12th Five-Year Plan and accelerated the construction during the 14th Five-Year Plan. To date， 10 UGS facilities for complex hydrocarbon reservoirs have been built successively. Through technological innovation and integration， SINOPEC has developed a series of key technologies for the construction and operation of complex hydrocarbon reservoir-based UGS facilities. The study results demonstrate that a range of technologies have provided comprehensive technical support for the high-quality construction and safe operation of SINOPEC’s UGS facilities. These technologies include the pressure-bearing capacity assessment of UGS facilities for fault-block reservoirs， injection-production capacity prediction of UGS facilities for ultra-high-pressure fractured reservoirs， enhanced recovery synergistic with gas storage construction in active gas reservoirs with high gas condensate content， construction of UGS facilities for fully waterflooded gas reservoirs， and the operation optimization of UGS facilities for water-drive gas reservoirs. In the future， it is advisable to enhance the capabilities for peak shaving and supply assurance of natural gas by optimizing the gas storage and peak-shaving structures and continuously constructing UGS facilities for both hydrocarbon reservoirs and salt caverns. It is essential to further exploring the peak-shaving potential of existing UGS facilities to improve economic benefits. Additionally， the development of intelligent UGS systems will pioneer diversified carbon-reduction pathways and renewable energy integration， fostering sustainable and green development of gas storage operations.