A Petrophysical and Shallow Geophysical Study To Determine Pathways of Gas Migration within and above an Underground Gas Storage Field in North-Central Illinois
Date of Award
Master of Science (MS)
Eric W. Peterson
Robert S. Nelson
The purpose of this study is to delineate the probable pathways of gas migration within and above a gas storage reservoir in North-Central Illinois. Mud logs and recorded formation tops were used to determine formation properties. A seismic survey with both P-wave and SH-wave and well log analysis including density porosity and gamma ray logs were utilized to define the gas migration pathways. The SH-wave seismic survey area included all of the surficial area utilized in the injection and withdrawal of the gas, the gathering system and areas to both the east and west. The Pwave seismic survey covered some of the same areas as the SH-wave, but not all. Gamma ray logs from numerous wells within the gas storage field including both production and observation wells were analyzed to determine the volume of shale (Vsh) within each of the formations and units within the reservoir. Three newly installed and logged wells provided the density porosity curves needed to analyze each formation within and above the reservoir. Finally, due to the age of the gathering system and the results from all of the above, it was found that the gas could be migrating to the surface or surficial bedrock by way of faults and fractures or mechanical problems within the wells themselves.
Hunt, Lauren I., "A Petrophysical and Shallow Geophysical Study To Determine Pathways of Gas Migration within and above an Underground Gas Storage Field in North-Central Illinois" (2004). Theses and Dissertations. 1031.