Abstract
Many field observations have indicated that permeabilities of both conventional and unconventional gas reservoirs are not constant when gas pressure drops. For conventional reservoirs, permeability will decrease while for unconventional gas rocks, the apparent permeability may increase as gas pressure decreases to a lower magnitude. Evolution trends of permeability for different natural gas reservoirs are distinct. These differences are observed by laboratory experiments of sandstones, coals, or shales. In this study, we present a general permeability model to bridge the gaps between conventional and unconventional gas reservoirs. This model coupled three critical factors namely effective stress, adsorption, and flow regimes to reflect dynamic performances of permeability. On the basis of specific reservoirs properties, the model degenerates into four reduced types. The first reduced model is applicable for reservoirs with lower adsorption capacity. The second reduced model is adopted by unconventional re...
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call