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Energy Policy Blog By Edith Allison

Carbon Capture and Sequestration–Expensive and Unproven

Carbon capture and sequestration (CCS) is perhaps commercially viable but not proven at commercial scale, according to 100 clean-energy experts that recently released their recommendations to the White House: 'Powering Forward: Presidential and Executive Agency Actions to Drive Clean Energy in America.'

Added on 03 February, 2014

Explorer Division Column EMD By Jeremy Boak

Report: A State of the EMD Union Update

Every six months, chairs of the Energy Minerals Division committees convene and report on developments in the areas they cover. In this column, we highlight important observations from these recent reports.

Added on 01 February, 2014

Bulletin Article

Gas saturation and CO2 enhancement potential of coalbed methane reservoirs as a function of depth

The influence of moisture, temperature, coal rank, and differential enthalpy on the methane (CH4) and carbon dioxide (CO2) sorption capacity of coals of different rank has been investigated by using high-pressure sorption isotherms at 303, 318, and 333 K (CH4) and 318, 333, and 348 K (CO2), respectively. The variation of sorption capacity was studied as a function of burial depth of coal seams using the corresponding Langmuir parameters in combination with a geothermal gradient of 0.03 K/m and a normal hydrostatic pressure gradient. Taking the gas content corresponding to 100% gas saturation at maximum burial depth as a reference value, the theoretical CH4 saturation after the uplift of the coal seam was computed as a function of depth. According to these calculations, the change in sorption capacity caused by changing pressure, temperature conditions during uplift will lead consistently to high saturation values. Therefore, the commonly observed undersaturation of coal seams is most likely related to dismigration (losses into adjacent formations and atmosphere). Finally, we attempt to identify sweet spots for CO2-enhanced coalbed methane (CO2-ECBM) production. The CO2-ECBM is expected to become less effective with increasing depth because the CO2-to-CH4 sorption capacity ratio decreases with increasing temperature and pressure. Furthermore, CO2-ECBM efficiency will decrease with increasing maturity because of the highest sorption capacity ratio and affinity difference between CO2 and CH4 for low mature coals.

Added on 31 January, 2014

Bulletin Article

Geologic and baseline groundwater evidence for naturally occurring, shallowly sourced, thermogenic gas in northeastern Pennsylvania

The origin of thermogenic natural gas in the shallow stratigraphy of northeastern Pennsylvania is associated, in part, with interbedded coal identified in numerous outcrops of the Upper Devonian Catskill and Lock Haven Formations. Historically documented and newly identified locations of Upper Devonian coal stringers are shown to be widespread, both laterally across the region and vertically throughout the stratigraphic section of the Catskill and Lock Haven Formations. Coal samples exhibited considerable gas source potential with total organic carbon as high as 44.40% by weight, with a mean of 13.66% for 23 sample locations analyzed. Upper Devonian coal is thermogenically mature; calculated vitrinite reflectances range from 1.25% to 2.89%, with most samples falling within the dry-gas window. Source potential is further supported by gas shows observed while drilling through shallow, identifiable coal horizons, which are at times located within fresh groundwater aquifers. Thermogenic gas detected in area water wells during predrill baseline sampling is determined not only to be naturally occurring, but also common in the region.

Added on 31 January, 2014

Bulletin Article

Prediction of channel connectivity and fluvial style in the flood-basin successions of the Upper Permian Rangal coal measures (Queensland)

Predicting the presence and connectivity of reservoir-quality facies in otherwise mud-prone fluvial overbank successions is important because such sand bodies can potentially provide connectivity between larger neighboring sand bodies. This article addresses minor channelized fluvial elements (crevasse-splay and distributary channels) and attempts to predict the connectivity between such sand bodies in two interseam packages of the Upper Permian Rangal Coal Measures of northeastern Australia. Channel-body percent as measured in well logs was 2% in the upper (Aries-Castor) interseam and 17% in the lower (Castor-Pollux) interseam. Well spacing were too great to allow accurate correlation of channel bodies. The Ob River, Siberia, was used as a modern analog to supply planform geometric measurements of splay and distributary channels so that stochastic modeling of channel bodies was possible. The resulting models demonstrated that (1) channel-body connectivity is more uniform between minor distributary channels than between crevasse-splay channels; (2) relatively good connectivity is seen in proximal positions in splays but decreases distally from the source as channel elements diverge; and (3) connectivity tends to be greater down the axis of splays, with more isolated channel bodies occurring at the margins.

Added on 31 January, 2014

Energy Policy Blog By Edith Allison

Oil Shale May Almost Be Commercial, or Not

Not oil, not shale, but a huge resource! Industry interest in developing oil shale production technology rises and falls with oil prices and the availability of cheaper options. Shale oil in formations like the Bakken is currently more economically attractive and less risky. Chevron, Shell and Exxon-Mobil have ended their oil shale projects in the past year, but Red Leaf Resources is moving ahead.

Added on 27 January, 2014

Explorer Policy Watch By Edith Allison

Report Shows Need for Data in Health Debate

The recent National Academies’ Institute of Medicine (IOM) report on its late-April 2012 workshop, “Health Impact Assessment of Shale Gas Extraction,” describes many potential health impacts of shale gas development and identifies the data gaps.

Added on 01 January, 2014

Explorer Emphasis Article By Louise Durham

3-D Seismic Drives Geosteering Advances

New geosteering tools are helping to drive eye-raising crude oil production levels in the Bakken shale play.

Added on 01 January, 2014

Explorer Article By Brian Ervin

The second annual Playmaker Forum will build on the success of last year’s event, offering professional development, networking, and tricks of the trade from some of the best oil finders in the world.

Added on 01 January, 2014

Explorer Article By David Brown

No Elephants, But Plenty of Potential for 2014

A review of major oil and gas discoveries of 2013 shows a down year in terms of quantity—but that’s not the whole story.

Added on 01 January, 2014

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AAPG 2022 Strategic Planning Survey Summary

Executive summary of the AAPG 2022 Member/Customer Planning Survey

Added on 05 April, 2023

wwwUpdate Blog

Advertise With Us!

AAPG publications are widely read by geologists, geophysicists and reservoir engineers. Are they your target audience? Then take advantage of the many advertising opportunities available in AAPG’s news and journal magazines.

Added on 13 April, 2018

wwwUpdate Blog By Grant Smith

Free Access to AAPG's Discovery Series 10 and 15 Full Data Set Tutorials

Courtesy of AAPG and AAPG Datapages, two Discovery Series data sets have been donated free of charge for use as online teaching materials. Discovery Series 10 – Sandstone Petrology: A Tutorial Petrographic Image Atlas 2nd Edition and Discovery Series 15 – Carbonate Petrology: Interactive Petrography Tutorial, both authored by Kitty Milliken, have been posted online for easy accessibility.

Added on 11 May, 2020