Measured Z-Factor of CO2--Dry Gas/Wet Gas/Gas Condensates for CO2 Storage in Depleted Gas Reservoirs

Suitability of depleted gas reservoirs for geological CO2 storage: A simulation study

“…In the first step, the composition of dry, wet, and condensate gas at the depleted stage was taken from the literature. 22 Adisoemarta et al 22 used these compositions to calculate the compressibility factor for storage purposes in depleted gas reservoirs. In the data preparation stage, by Adisoemarta et al, 22 the hydrocarbon components were normalized and analyzed to find the median composition for each category of gas reservoirs.…”

“…22 Adisoemarta et al 22 used these compositions to calculate the compressibility factor for storage purposes in depleted gas reservoirs. In the data preparation stage, by Adisoemarta et al, 22 the hydrocarbon components were normalized and analyzed to find the median composition for each category of gas reservoirs. Table 1 gives the normalized median composition for each category of gas reservoir used for the purpose of this study.…”

“…Condensate gas, which has the maximum residual and dissolved CO 2 saturations, shows its maximum storage capacity during and after injection, as discussed earlier. 22 Comparison of the dry base, wet base, and the condensate base cases shows that the storage medium with condensate gas has a significant impact on the total storage capacity due to favorable residual and dissolution trapping. This may indicate that a highly compressible fluid-like condensate gas is favorable to immobilize large fraction of CO 2 in the form of residual and dissolved phases.…”

“…49,50 Table 3 summarizes the material balances (total injected CO 2 , stored CO 2 , and maximum pressure buildup) of dry base, wet base, and condensate base cases. Generally, the condensate gas type has a high compressibility and, as such, it offers a larger storage capacity than dry and wet gas system, 22,23 as shown in Fig. 6.…”

“…20 For instance, some gas reservoirs may cause loss of injectivity, overpressurization or less CO 2 immobilization as the mixture of CO 2 with the residual gas may change the properties of the CO 2 and gas mixture. 15,18,[21][22][23] In the meantime, CO 2 mixing with resident gas depends on the reservoir geometry, anisotropy, heterogeneity, injection rate, time of injection, rock or fluid properties, and diffusion, which can only be studied through numerical simulation. In this paper, a 3D numerical model was built based on the modified Peng-Robinson equation to explore the feasibility of gas reservoirs for long-term CO 2 storage.…”