Study of Viability of Seismic
Imaging for
Site Selection and Monitoring of CO2 Sequestration in Illinois Thin
Coal Seams*
By
Iraj A. Salehi1, Sherif I. Gowelly1, and Samih I. Batarseh1
Search and Discovery Article #80004 (2006)
Posted October 16, 2006
*Oral presentation at AAPG Annual Convention, Houston, Texas, April 9-12, 2006.
Click to view presentation in PDF format (~3.9 mb).
Click to view presentation (with accompanying Notes) in PDF format (~2.2 mb).
1Gas Technology Institute, Des Plaines, IL ([email protected])
Abstract
In this paper, we present results of a series of field and laboratory
experiments aimed at determination of seismic
resolution relative to thin
Illinois coal seams and study of viability of time-lapsed
seismic
imaging (4-D
seismic
) for monitoring the position of the injected carbon dioxide front during
CO2 sequestration process, or desorbed methane in the case of coalbed
methane production. The project was a cooperative effort between Illinois Clean
Coal Institute (ICCI) and Gas Technology Institute (GTI) with valuable technical
contribution and logistical support from Illinois State Geological Survey (ISGS).
Illinois coal seams are shallow and thin with the thickness rarely exceeding 10
feet. To investigate viability of seismic
technology relative to imaging of
Illinois coal seams a series of
seismic
data acquisitions including surface
seismic
, vertical
seismic
profiling, and crosswell
seismic
imaging carried out
at the ISGS pilot site in Southern Illinois. Results were encouraging in that
the data proved that thin coal seams can be reliably mapped by properly designed
seismic
surveys.
Our second objective was to verify viability of 4-D seismic
as a monitoring tool
for the potential CO2 sequestration projects in coal seams of
Illinois. In pursuing this objective, a number of elaborate laboratory
measurements of acoustic velocity in gas and water saturated coal samples were
carried out. Results of these measurements showed that the magnitude of velocity
change resulting from addition of a gas phase into water saturated coal samples
is large enough to render the time-lapsed
seismic
technique useful for
monitoring the position of injected or evolved gas fronts.
Selected Figures
Location map of four |
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Final processed broadband
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Crosswell |
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Summary of results of |