Explorer Emphasis Article
By Louise Durham
Rocky Mountain high? Operators throughout the Rocky Mountains region have reasons to be cautious – but just as many reasons to smile.
American Association of Petroleum Geologists (AAPG)
Added on 01 June, 2013
Explorer Spotlight On…
By Susie Moore
How did he stay so cool? Sticking to the facts was key in dealing with the public and media during the aftermath of explosion at Macondo.
American Association of Petroleum Geologists (AAPG)
Added on 01 June, 2013
Explorer Emphasis Article
By Louise Durham
Look again: The Bakken shale play is so big the U.S. Geological Survey has made a new assessment of the formation to see what has changed since the last assessment in 2008.
American Association of Petroleum Geologists (AAPG)
Added on 01 April, 2013
Bulletin Article
Characterization of oil shale kerogen and organic residues remaining in postpyrolysis spent shale is critical to the understanding of the oil generation process and approaches to dealing with issues related to spent shale. The chemical structure of organic matter in raw oil shale and spent shale samples was examined in this study using advanced solid-state 13C nuclear magnetic resonance (NMR) spectroscopy. Oil shale was collected from Mahogany zone outcrops in the Piceance Basin. Five samples were analyzed: (1) raw oil shale, (2) isolated kerogen, (3) oil shale extracted with chloroform, (4) oil shale retorted in an open system at 500C to mimic surface retorting, and (5) oil shale retorted in a closed system at 360C to simulate in-situ retorting. The NMR methods applied included quantitative direct polarization with magic-angle spinning at 13 kHz, cross polarization with total sideband suppression, dipolar dephasing, CHn selection, 13C chemical shift anisotropy filtering, and 1H-13C long-range recoupled dipolar dephasing. The NMR results showed that, relative to the raw oil shale, (1) bitumen extraction and kerogen isolation by demineralization removed some oxygen-containing and alkyl moieties; (2) unpyrolyzed samples had low aromatic condensation; (3) oil shale pyrolysis removed aliphatic moieties, leaving behind residues enriched in aromatic carbon; and (4) oil shale retorted in an open system at 500C contained larger aromatic clusters and more protonated aromatic moieties than oil shale retorted in a closed system at 360C, which contained more total aromatic carbon with a wide range of cluster sizes.
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American Association of Petroleum Geologists (AAPG)
Added on 28 February, 2013
Explorer Foundation Update
By Natalie Adams
The Foundation Trustees approved three major funding requests when the group met in late November.
American Association of Petroleum Geologists (AAPG)
Added on 01 January, 2013
Bulletin Article
Select lacustrine and marine depositional settings show a spectrum of styles of carbonate deposition and illustrate the types of carbonates, with an emphasis on microbialites and tufa, to be expected in early rift settings. Early rift lake examples examined in this review article are all from East Africa: Lakes Turkana, Bogoria, Natron and Magadi, Manyara, and Tanganyika. Other lake examples include four from the western United States (Great Salt Lake and high lake level Lake Bonneville, Mono Lake and high lake level Russell Lake, Pyramid Lake and high lake level Lake Lahontan, and Searles Lake) and two from Australia (Lakes Clifton and Thetis). Marine basin examples are the Hamelin Pool part of Shark Bay from Australia (marginal marine) and the Red Sea (marine rift).
Landsat images and digital elevation models for each example are used to delineate present and past lake-basin margins based on published lake-level elevations, and for some examples, the shorelines representing different lake levels can be compared to evaluate how changes in size, shape, and lake configuration might have impacted carbonate development. The early rift lakes show a range of characteristics to be expected in lacustrine settings during the earliest stages of continental extension and rifting, whereas the Red Sea shows well advanced rifting with marine incursion and reef–skeletal sand development. Collectively, the lacustrine examples show a wide range of sizes, with several of them being large enough that they could produce carbonate deposits of potential economic interest. Three of the areas—Great Salt Lake and high lake level Lake Bonneville, Pyramid Lake and high lake level Lake Lahontan, and the Red Sea—are exceedingly complex in that they illustrate a large degree of potential depositional facies heterogeneity because of their size, irregular pattern, and connectivity of subbasins within the overall basin outline.
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American Association of Petroleum Geologists (AAPG)
Added on 31 December, 2012