Perpustakaan Digital ITB

The effect of adsorption is generally not considered in CCUS (Carbon Capture Utilization and Storage) projects, especially related to Enhanced Gas Recovery (EGR). The reason is because the addition of adsorption parameter to the reservoir simulation data input will make the reservoir model more complex in terms of reservoir model properties. Moreover, the duration of running the reservoir simulation model will be much longer. This study showed the effect of adsorption during EGR, although it is implemented to a simple input model and simple reservoir parameters that are taken from published data. The size of the model is about 2,639.7 x 2,639.7 x 650 ft3, and the model is divided into regular grid sizes of 293.3 ft (for x and y directions) and varies depth sizes, namely 50 ft for the first two cells, 30 ft for the next two cells, and the rest cells are 25 ft. Therefore, the total depth is 650 ft (for z direction). Four (4) injection wells are situated on the edges of the model, with a CO2 injection rate of 2.5 MMSCFD per day for each well. The production well is situated on the centre of the model. The simulation is started on 1 January 2022 and duration of the simulation is 228 years with a time interval variation of every month (2022 – 2025), every minute (only on 1 – 2 May 2025 in order to see the precise breakthrough time to the production well), and every year (implemented to the rest of simulation periods). The results of this study show the adsorption effect quite clearly, in which higher hydrocarbon gas production is obtained (due to EGR), whereas the production of CO2 is smaller than if the simulation is not incorporated adsorption effect. Thus, the lack of CO2 gas in the production well is caused by adsorption effects. In other word it could be said that the higher yield of hydrocarbon gas is caused by smaller CO2 gas that is being produced due to adsorption, although smaller CH4 is also adsorbed. It is believed that some of the injected CO2 is adsorbed by the clay minerals in the reservoir. The ability of clay minerals to adsorb CO2 and CH4 will differ depending on the level of purity of the clay. The purer the clay mineral, the better the clay mineral in adsorption of CO2 and CH4. With more CO2 being adsorbed by clay minerals, the CO2 breakthrough time is proven to be longer. The results of the reservoir simulation in this study show that with incorporating adsorption effect, there will be additional 0.025 million ton of CH4 gas production and can sequestrate additional 0.07 million ton of CO2 than that without adsorption effect.