Reservoir characteristics and light hydrocarbon channeling revealed by production data: A case study of liquid rich Duvernay shale play with emphasis in Fox Creek area, Alberta Canada

Abstract

This paper reports the findings on the major factors affecting the hydrocarbon productivity and ultimate resource recovery from the liquid-rich Duvernay Shale play in the Fox Creek area. Essential drilling and completion parameters, production rate, estimated ultimate reserves from monthly production time series and key geological variables were mapped and combined with statistical data analysis to reveal their spatial variation and statistical relationships among these parameters and variables. We found that fluid type of the hydrocarbons in shales is essential for hydrocarbon productivity and estimated ultimate recovery (EUR) in this area. Although production rate and EUR are proportional to measures of hydraulic treatment, not all the completion parameters are equally effective in enhancing productivity and recovery. Fracking water volume seems to boost productivity and recovery the most. Parameters from organic geochemistry and geology are essential for mapping the boundary of the resource play, and determining the hydrocarbon fluid types and their spatial variations. And high positive correlation of HCPV with monthly average production rate and EUR indicates the importance of those geological factors for the productivity and ultimate recovery of the study area. Gas-to-oil ratio (GOR) mapping from produced fluids in the first 12 months reveals high anomalous GOR channels or linear zones in low maturity areas that are inconsistent with thermal maturity trends spatially, indicating intra-formation migration of hydrocarbon fluids in the source rock along permeable networks. Major earthquake swarms induced by hydraulic fracturing appear to be associated with crossing formation faults, and are spatially coincident with reduced productivity and ultimate recovery in de-pressured reservoir spot. These findings provide insights to better understand the distribution of production sweet spots and for production optimization strategies to facilitate a low carbon energy transition.