Effect of CO2 injectivity on enhanced shale gas recovery

Xiang Li, Derek Elsworth

Research output: Chapter in Book/Report/Conference proceedingConference contribution

5 Scopus citations

Abstract

Shale gas has become an increasingly important source of natural gas (CH4) in the United States over the last decade. Due to its unconventional characteristics, injecting carbondioxide (CO2) to enhance shale gas recovery (ESGR) is a potentially feasible method to increase gas-yield while both affording a sink for CO2 and in reducing the potential for induced seismicity. This study examines CO2-ESGR to better understand its feasibility and effectiveness. We explore the roles of important coupled phenomena activated during gas substitution especially vigorous feedbacks between sorptive behavior and permeability evolution. Permeability and porosity evolution models developed for sorptive fractured coal are adapted to the component characteristics of gas shales. These adapted models are used to probe the optimization of CO2-ESGR for injection of CO2 at overpressures of OMPa, 4MPa and 8MPa to investigate magnitudes of elevated CH4 production, CO2 storage rate and capacity, and of CO2 early-breakthrough and permeability evolution in the reservoir. For the injection pressures selected, CH4 production was enhanced by 2.3%, 14.3%, 28.5%, respectively, over the case where CO2 is not injected. Distinctly different evolutions are noted for permeability in both fractures and matrix due to different dominating mechanisms. Fracture permeability increased by 1/3 for the injection scenarios due to the dominant influence of CH4 de-sorption over CO2 sorption. CO2 sequestration capacity was only of the order of 104 m3 when supercritical for a net recovery of CH4 of 108 m3.

Original languageEnglish (US)
Title of host publication48th US Rock Mechanics / Geomechanics Symposium 2014
EditorsLee Petersen, Ray Sterling, Emmanuel Detournay, Will Pettitt, Joseph F. Labuz
PublisherAmerican Rock Mechanics Association (ARMA)
Pages1183-1192
Number of pages10
ISBN (Electronic)9781634395236
StatePublished - 2014
Event48th US Rock Mechanics / Geomechanics Symposium 2014: Rock Mechanics Across Length and Time Scales - Minneapolis, United States
Duration: Jun 1 2014Jun 4 2014

Publication series

Name48th US Rock Mechanics / Geomechanics Symposium 2014
Volume2

Other

Other48th US Rock Mechanics / Geomechanics Symposium 2014: Rock Mechanics Across Length and Time Scales
Country/TerritoryUnited States
CityMinneapolis
Period6/1/146/4/14

All Science Journal Classification (ASJC) codes

  • Geotechnical Engineering and Engineering Geology

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