Vertical gas migration associated with coal seam gas production
Ludovic Ricard A and Julian Strand ACSIRO Energy.
The APPEA Journal 56(2) 602-602 https://doi.org/10.1071/AJ15108
Published: 2016
Abstract
Gas migration outside coal seam gas reservoirs has been identified as a risk associated with CSG production. While such an event has not been reported or scientifically associated with CSG production, understanding the physical mechanism of the vertical migration in the overburden involved should gas leakage occur would improve mitigation strategies and risk evaluation.
In this extended abstract, a series of key modelling scenarios of gas migration above the reservoir are developed. Interpretation of the scenarios highlights that:
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the seal/leakage nature of the overburden strongly impacts gas migration and volume of gas leaked;
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when leakage does occur, the leaked volume represents a very small portion of the original gas in place and volume of gas produced;
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the connectivity of the overburden plays a critical role on the gas migration pathways and volume of gas leaked; and,
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residual gas saturation, and relative permeability hysteresis provide means to trap the mobile gas, significantly reducing the volume of gas leaked reaching shallower formations.
Ludovic Ricard is a reservoir engineer at CSIRO Energy. He holds a MSc on fluid and mechanical engineering from University of Bordeaux 1 and a PhD in earth science from University of Paris XI. Ludovic completed his Post-doctoral Fellowship at Heriot Watt University (Edinburgh, UK), focusing on well test and 4D seismic interpretation. He joined CSIRO Energy as reservoir engineer for geothermal energy projects, later moving to carbon geosequestration storage and unconventional reservoirs. Member: ASEG, IAH, EAGE, PESA and SPE. |
Julian Strand is a Senior Research Scientist at CSIRO Petroleum/Earth Science and Resource Engineering, primarily working on structural geology and issues related to incorporating structural geology into reservoir and basin models. He has been based in Perth since 2005, and is a member of the AAPG and EAGE. Julian was part of the Fault Analysis Group for nine years at the University of Liverpool and latterly UCD in Ireland. He attended the University of Liverpool and Imperial College, London. |
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