Study of CO2 Injection into Sumatran Shale Layers to increase Hydrocarbon Gas Productivity of The Shale Gas Reservoir

Abstract

Injecting CO2 into a reservoir has some important reasons. CO2 injection can enhance oil and gas recovery by reducing the capillary pressure, increasing the pressure gradient, and changing the phase behavior of the fluids. It can reduce greenhouse gas emissions by capturing and storing CO2 underground. It can also create economic benefits by utilizing CO2 as a valuable resource and generating revenue from carbon credits. Therefore, injecting CO2 into a reservoir benefits the environment and the industry. We can inject CO2 in shale gas reservoirs to increase productivity because CO2 has a stronger adsorption capacity on shale surfaces than hydrocarbon gas. When CO2 is injected into shale reservoirs, it can displace the adsorbed CH4 flow out of the micropores and free up more space for gas flow. Injecting CO2 can also reduce the viscosity and density of shale gas, improving its mobility and transport. Moreover, injecting CO2 can provide environmental benefits by reducing carbon emissions and storing CO2 underground. Therefore, CO2 injection is a promising technique for enhancing shale gas recovery and mitigating climate change. We characterized several types of shale from Sumatra using XRD to determine the mineral content. We injected the shale sample with the inert gas and CO2 gas. The characteristics of pressure build up after CO2 injection seem lower than one after inert gas injection. The volumetric of released gas after injection shows the same phenomena as pressure build up’s phenomena which shows clearly that shale rock released less of CO2 gas than the one of inert gas (CH4). These phenomena show that the CH4 can be released easier than the CO2 in the shale rock. Therefore, CO2 can be utilized as material for enhancing the gas recovery in shale reservoir.