The status quo and technical development direction of underground gas storages in China

Abstract

UGS (underground gas storage) construction in China has stepped into a new development stage after years of exploration. The eleven UGSs that have been put into production play an important role in domestic natural gas peak shaving safety and supply guarantee, with designed working gas volume of 180 × 108 m3, but there are still various difficulties in UGS construction in China. Firstly, the increasing speed of working gas volume is slower than that of peak shaving demand volume. Secondly, the UGS building engineering is difficult in technologies and high in investment costs. Thirdly, safe operation is under high pressure and it is hard to identify and control risks. Fourthly, there are fewer candidate UGS sites in China and UGS building conditions are complicated. And fifthly, it is difficult for those UGSs to realize economic benefits only based on their own operation under the existing natural gas price systems. To sum up, the currently available UGS operation modes and building technologies in China are not sufficient to cope with the challenges resulted from markets and complex geologic conditions. Facing all these challenges, it is necessary not only to explore market driven operation modes, but also to strengthen technology tackling and carry out core technological research and development, including geologic evaluation, gas reservoir engineering, drilling and completion engineering, UGS injection and gas recovery engineering, surface auxiliary technologies and UGS integrity evaluation, so that UGS building efficiency can be increased greatly.