Characteristics of Canister Core Desorption Gas from Unconventional Reservoirs and Applications to Improve Assessment of Hydrocarbons-in-Place

Canister core desorption has been successfully applied to coal-bed methane evaluation and exploitation as the technique eliminates need for time-consuming down-hole fluid retrieval through flow testing. The also used exploration of early-stage tight shale gas reservoirs in recent years, although its success applicability are poorly understood. In this study, we analyzed a comprehensive canister data set on 230 samples from nine wells drilled into Montney Formation northeastern British Columbia part Western Canada Sedimentary Basin (WCSB). purpose study was illustrate characteristics rocks relationship reservoir properties operational parameters. Based measured (e.g., porosity, saturation, permeability, total organic carbon (TOC) content, adsorption isotherms) adjacent samples, non-isothermal transport cores modeled quantify lost during recovery time at surface. Gas volumes were subsampled by tests. results show that contents on-site only accounts minor (but significant) portion (about 2 25%) gas-in-place cores, with lower percentages being associated better qualities higher porosity). Over 60–90% (mainly free gas) can be recovery, up 10% surface, prior desorption. is mainly adsorbed gas, hence shows strong positive correlation TOC content. current test method severely underestimates in-situ content because it fails correctly estimate limiting successful application technique. Nevertheless, bulk molecular compositions gases strongly correlated those produced same area, exhibiting distinctive composition profiles throughout different types or thermal maturity, thus provide invaluable information initial unconventional plays. A workflow EOS-based PVT property compositional modeling proposed integrate analysis mud and/or improved characterization situ fluids, hence, assessments hydrocarbons-in-place evaluations reservoirs.