Design of Tracer Tests for Natural Gas Underground Storage Operations - A Simulation Approach

Abstract

Abstract Chinese Petroleum Corporation started the import of Liquified Natural Gas (LNG) from Indonesia in 1990 and utilized a depleted gas reservoir, Tiehchenshan Gas Field, to store the surplus LNG. With a compositional reservoir simulator, this paper investigated the feasibility of using CO2 as a tracer for monitoring the flow path of injected LNG. The CO2 content in the Tiehchenshan gas and Indonesia LNG is around 2 mole % and 0 mole %, respectively. The simulation results indicated that monitoring the CO2 concentration change at the producing wells would help understand the flow path of the injected gas and the reservoir description for Tiehchenshan Gas Field. Currently, compositional simulators seldom take the radioactive decay into account. This paper successfully developed a simple method which would allows the users of compositional simulators to design a test using a radioactive tracer. The simulation results showed that the mechanism of radioactive decay must be taken into account during the design and analysis of radioactive tracer tests for underground gas storage operations.