Pilot test of study on brine injection into shallow formation for mitigating land subsidence in the Southern Kanto Gas Field in Japan

Abstract

In the Southern Kanto Gas Field, natural gas dissolved in water has been produced for over 80 years. In order to produce the natural gas dissolved in water, formation water must be pumped from a reservoir in the gas field. The production of formation water is considered to be one of the causes of land subsidence. Because brine injection into shallow formations is expected to be effective to mitigate land subsidence, our association is planning to conduct the pilot test study. In this test, the production and injection of brine are going to be performed, and we will observe a deformation of the shallow formation and a change of ground level and the bottom hole pressure. As a result of these tests, if the land subsidence mitigation effect by injection into shallow formation is confirmed, it is expected that it will be connected to increased production and to reservoir management in consideration of land subsidence mitigation in the future.