Effects Of Permeability and Pore Connectivity On Gas Trapping In Carbonate Rocks

Resumo

Trapped gas is a significant factor affecting the hydraulic properties of oil reservoirs, including re-
coverable oil reserves. The degree of trapped gas in oil fields is a crucial aspect that affects the convergence of

recoverable reserves, which has been evaluated in different experimental and simulation studies. These studies
aim to assess the impact of trapped gas on different rock properties, as it is crucial for the Advanced Oil Recovery
(EOR) and Carbon Capture, Use and Storage (CCUS) scenarios. several studies show that air or gas entrapment is
a function of many parameters, including the prevailing wetting rate, wettability, and especially grain texture and

pore structure. Understanding and quantifying the effects of trapped gas in oil reservoirs is challenging, partic-
ularly for carbonate rocks that have an unusually complex multiscale heterogeneous pore structure, causing fluid

retention and unique flow properties. the same is not observed for carbonate rocks. This study examined how

permeability and pore connectivity interact to influence saturation levels of trapped gas in 47 representative sam-
ples of carbonate rock formations. The 3D characterization of the pore space was made possible through microCT

images, obtained for the silurian dolomite and coquina samples. It has been observed that larger pore radii and
better connectivity lead to increased gas trapping, even in cases where pore connectivity may be more pronounced.
This contrasted with previous assumptions emphasizing the influence of pore structure on gas trapping.