James A. Drahovzal

Analysis of Devonian black shales in kentucky for potential carbon dioxide sequestration and enhanced natural gas production

Publisher Summary Organic matter in the Devonian gas shales has large surface areas similar to that found in coal. Coal seams are currently being investigated as potential sequestering sites for CO2—the most important greenhouse gas. Naturally occurring organic matter (kerogen) is a microporous material that possesses a very high surface area and, hence, sorption capacity for gas. Drill cuttings from the Kentucky Geological Survey Well Sample and Core Library are being sampled to collect CO2 adsorption isotherms. To investigate any relation between organic content and CO2 sorption capacity, total organic carbon content (TOC) was determined. To measure thermal maturity, mean random reflectance on dispersed vitrinite particles in the samples was determined on a Zeiss USMP incident light microscope calibrated using glass standards of known reflectance. Sidewall core samples have been acquired to investigate CO2 displacement of methane. An electron capture spectroscopy log has been acquired to investigate possible correlations between adsorption capacity and mineralogy.

RESOURCE ASSESSMENT & PRODUCTION TESTING FOR COAL BED METHANE IN THE ILLINOIS BASIN

The geological surveys of Illinois, Indiana and Kentucky have completed the initial geologic assessment of their respective parts of the Illinois Basin. Cumulative thickness maps have been generated and target areas for drilling have been selected. The first well in the Illinois area of the Illinois Basin coal bed methane project was drilled in White County, Illinois in October 2003. This well was cored in the major coal interval from the Danville to the Davis Coals and provided a broad spectrum of samples for further analyses. Sixteen coal samples and three black shale samples were taken from these cores for canister desorption tests and were the subject of analyses that were completed over the following months, including desorbed gas volume, gas chemical and isotope composition, coal proximate, calorific content and sulfur analyses. Drilling programs in Indiana and Kentucky are expected to begin shortly.

Hydrothermics in the Wyoming Overthrust Belt

A thermal study was made across a 25 km (15.5 mi) traverse of the Overthrust belt in southwestern Wyoming. Estimates of relative heat flow from temperature measurements made in shallow (< 30 m or 98 ft) boreholes reveal a systematic variation of at least 400 mW/m2 (10 µcal/cm2 sec) magnitude across the study area. The cause of this variation is believed to be forced convection of heat by moving ground water. Two relative heat-flow highs coincide with zones where structurally related faults, possibly providing avenues for vertical water flow, project to the surface. Between those two zones in a topographically elevated area, low and predominately negative temperature gradients were observed in opposite seasons. These shallow negative gradients are believed to exist seasonally in quasisteady state and could be indicative of a broad zone of ground-water recharge. The association of two relative heat-flow highs with the two major deep geologic structures implies either a direct vertical communication of deep and shallow ground water or a coupling of deeper and shallower ground-water systems. The two structures studied are hydrocarbon bearing and associated with Whitney Canyon and Ryckman Creek fields. The thermal measurements support the possibility that ascending waters have influenced the hydrocarbon migration and accumulation in these structures. Such measurements may be useful in delineating and understanding similar features in other areas.