‘Communities’ Concept Starts to Grow

One of the AAPG Executive Committee’s priorities during the first five months of this fiscal year has been to study the Association’s science program with the goal of creating new conduits for generating and disseminating scientific content.

Fostering communities with specific geologic interests within the Association is an obvious strategy for meeting this goal.

I’m happy to report that under the leadership of Elected-Editor Steve Laubach and the past Vice President-Sections Marv Brittenham, AAPG is indeed considering ways to better empower “communities of interest” within AAPG – that is, community members who share common interests in specific geological subjects.

Several of these communities of interest already have self-organized within AAPG. One example is the “petroleum structure and geomechanics group,” chaired by Peter Hennings.

These informal groups are doing excellent science in the background of AAPG – and what we would like to do now is find ways to nurture them without harming them. Our fear is that by formalizing them we might stifle their enthusiasm or creativity.

At the same time, however, we would like to help them share their ideas with the rest of AAPG in new publications and short courses – and the best way to do that probably requires some type of formal structure.

As mentioned, we’re happy that at least one of these communities is ready for formal recognition – the petroleum structure and geomechanics group.

Our hope is that others will be ready in the near future.


A question being considered by the AAPG Advisory Council, led by past AAPG president Paul Weimer, is what should the formal recognition be?

Should it be as new divisions, like the Energy Minerals Division, for example? Or should it be some new entity within AAPG, like a “super committee” with authority to create new AAPG science products?

The best part about all of this: AAPG’s communities of interest are open to whoever is interested. They are intentionally very informal, so the trick is finding out about what they are and where they are meeting.

And right now, this is mostly accomplished by word of mouth.

If you are interested in starting one please let someone on the Executive Committee know and we will try to help.


On a different subject, in many places around the world December is a holiday season. And as such it is a perfect time to consider making a gift to the AAPG Foundation.

The Foundation supports many worthy and significant projects, including Scott Tinker’s movie “Switch,” the Imperial Barrel Award, AAPG’s open access website Search and Discovery, Distinguished Lecturers and Grants-in-Aid to students, just to name a few.

Any contribution is appreciated.

Have a wonderful holiday season!

Comments (0)

 

President's Column

President's Column - Ted Beaumont

Edward A. "Ted" Beaumont, AAPG President (2012-13), is an independent consultant with Cimarex Energy.

President's Column

AAPG Presidents offer thoughts and information about their experiences for the Association. 

VIEW COLUMN ARCHIVES

See Also: Bulletin Article

In reservoir engineering, hydrodynamic properties can be estimated from downhole electrical data using heuristic models (e.g., Archie and Kozeny-Carman's equations) relating electrical conductivity to porosity and permeability. Although proven to be predictive for many sandstone reservoirs, the models mostly fail when applied to carbonate reservoirs that generally display extremely complex pore network structures.

In this article, we investigate the control of the three-dimensional (3-D) geometry and morphology of the pore network on the electrical and flow properties, comparing core-scale laboratory measurements and 3-D x-ray microtomography image analysis of samples from a Miocene reefal carbonate platform located in Mallorca (Spain).

The results show that micrometer- to centimeter-scale heterogeneities strongly influence the measured macroscopic physical parameters that are then used to evaluate the hydrodynamic properties of the rock, and therefore, existing models might not provide accurate descriptions because these heterogeneities occur at scales smaller than those of the integration volume of the borehole geophysical methods. However, associated with specific data processing, 3-D imagery techniques are a useful and probably unique mean to characterize the rock heterogeneity and, thus, the properties variability.

Desktop /Portals/0/PackFlashItemImages/WebReady/electrical-and-flow-properties-of-highly-heterogeneous-carbonate-rocks.jpg?width=50&h=50&mode=crop&anchor=middlecenter&quality=90amp;encoder=freeimage&progressive=true 3251 Bulletin Article

Criteria for recognizing stratigraphic sequences are well established on continental margins but more challenging to apply in basinal settings. We report an investigation of the Upper Devonian Woodford Shale, Permian Basin, west Texas based on a set of four long cores, identifying sea level cycles and stratigraphic sequences in an organic-rich shale.

The Woodford Shale is dominated by organic-rich mudstone, sharply overlain by a bioturbated organic-poor mudstone that is consistent with a second-order eustatic sea level fall. Interbedded with the organic-rich mudstone are carbonate beds, chert beds, and radiolarian laminae, all interpreted as sediment gravity-flow deposits. Bundles of interbedded mudstone and carbonate beds alternate with intervals of organic-rich mudstone and thin radiolaria-rich laminae, defining a 5–10 m (16–33 ft)-thick third-order cyclicity. The former are interpreted to represent highstand systems tracts, whereas the latter are interpreted as representing falling stage, lowstand, and transgressive systems tracts. Carbonate beds predominate in the lower Woodford section, associated with highstand shedding at a second-order scale; chert beds predominate in the upper Woodford section, responding to the second-order lowstand.

Additional variability is introduced by geographic position. Wells nearest the western margin of the basin have the greatest concentration of carbonate beds caused by proximity to a carbonate platform. A well near the southern margin has the greatest concentration of chert beds, resulting from shedding of biogenic silica from a southern source. A well in the basin center has little chert and carbonate; here, third-order sea level cycles were primarily reflected in the stratigraphic distribution of radiolarian-rich laminae.

Desktop /Portals/0/PackFlashItemImages/WebReady/a-sequence-stratigraphic-framework-for-the-Upper-Devonian-Woodford-Shale.jpg?width=50&h=50&mode=crop&anchor=middlecenter&quality=90amp;encoder=freeimage&progressive=true 3250 Bulletin Article
Isolated carbonate buildups (ICBs) are commonly attractive exploration targets. However, identifying ICBs based only on seismic data can be difficult for a variety of reasons. These include poor-quality two-dimensional data and a basic similarity between ICBs and other features such as volcanoes, erosional remnants, and tilted fault blocks. To address these difficulties and develop reliable methods to identify ICBs, 234 seismic images were analyzed. The images included proven ICBs and other features, such as folds, volcanoes, and basement highs, which may appear similar to ICBs when imaged in seismic data. From this analysis, 18 identification criteria were derived to distinguish ICBs from non-ICB features. These criteria can be grouped into four categories: regional constraints, analysis of basic seismic geometries, analysis of geophysical details, and finer-scale seismic geometries. Systematically assessing the criteria is useful because it requires critical evaluation of the evidence present in the available data, working from the large-scale regional geology to the fine details of seismic response. It is also useful to summarize the criteria as a numerical score to facilitate comparison between different examples and different classes of ICBs and non-ICBs. Our analysis of scores of different classes of features suggests that the criteria do have some discriminatory power, but significant challenges remain.
Desktop /Portals/0/PackFlashItemImages/WebReady/methods-for-identification-of-isolated-carbonate.jpg?width=50&h=50&mode=crop&anchor=middlecenter&quality=90amp;encoder=freeimage&progressive=true 3767 Bulletin Article

See Also: CD DVD

Desktop /Portals/0/images/_site/AAPG-newlogo-vertical-morepadding.jpg?width=50&h=50&mode=crop&anchor=middlecenter&quality=90amp;encoder=freeimage&progressive=true 4518 CD-DVD

See Also: Online e Symposium

Upon successful completion of this course, you will be able to describe geomechanics in shale reservoirs and discuss differences between plays.

Desktop /Portals/0/PackFlashItemImages/WebReady/oc-es-all-shale-gas-reservoirs-are-not-the-same.jpg?width=50&h=50&mode=crop&anchor=middlecenter&quality=90amp;encoder=freeimage&progressive=true 1461 Online e-Symposium