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Person

Brett J Valentine

Physical Scientist

Geology, Energy & Minerals Science Center

Email: bvalentine@usgs.gov
Office Phone: 703-648-6480
Fax: 703-648-6419
ORCID: 0000-0002-8678-2431

Location
John W Powell FB
12201 Sunrise Valley Drive
Reston , VA 20192-0002
US

Supervisor: Evan A Bargnesi
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To test if reflectance increases to sedimentary organic matter (vitrinite) caused by broad ion beam (BIB) milling were related to molecular aromatization and condensation, we used Raman and Fourier transform infrared (FTIR) spectroscopies to evaluate potential compositional changes in the same vitrinite locations pre- and post-BIB milling. The same locations also were examined by atomic force microscopy (AFM) to determine topographic changes caused by BIB milling (as expressed by the areal root-mean-square roughness parameter Rq). Samples consisted of four medium volatile bituminous coals. We used a non-aggressive BIB milling approach with conditions of [(5 min, 4 keV, 15°incline, 360° rotation at 25 rpm and 100%...
Geological models for petroleum generation suggest thermal conversion of oil-prone sedimentary organic matter in the presence of water promotes increased liquid saturate yield, whereas absence of water causes formation of an aromatic, cross-linked solid bitumen residue. To test the influence of exchangeable hydrogen from water, organic-rich (22 wt.% total organic carbon, TOC) mudrock samples from the Eocene lacustrine Green River Mahogany zone oil shale were pyrolyzed under hydrous and anhydrous conditions at temperatures between 300 and 370°C for 72 hrs. Petrographic approaches including optical microscopy, reflectance, Raman spectroscopy, and scanning electron and transmission electron microscopy, supplemented...
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The U.S. Geological Survey assessed undiscovered unconventional hydrocarbon resources reservoired in the Upper Cretaceous Tuscaloosa marine shale (TMS) of southern Mississippi and adjacent Louisiana in 2018. As part of the assessment, oil- source rock correlations were examined in the study area where operators produce light (38-45° API), sweet oil from horizontal, hydraulically-fractured wells in an overpressured ‘high-resistivity’ (>5 ohm-m) zone (HRZ) at the base of the TMS. Our initial characterization of TMS samples indicated overall low organic carbon (avg. TOC ~1.0%) and dominance of a gas-prone Type III or mixed Type II/III kerogen, potentially inconsistent with a self-sourced petroleum system model for...
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This data release contains the boundaries of assessment units and input data for the assessment of undiscovered continuous oil and gas in the Upper Cretaceous Tuscaloosa Marine shale of the U.S. Gulf Coast. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set of known or postulated oil and (or) gas accumulations sharing similar geologic, geographic, and temporal properties...
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This study describes the application of organic petrology techniques to quantify the amount of coal and carbonaceous combustion by-products (i.e., coke, coal tar/pitch, cenospheres) in sediments taken from the Kinnickinnic River adjacent to the former site of the Milwaukee Solvay Coke and Gas Company. The site produced metallurgical coke and coal-gasification by-products from 1902-1983 and was assessed in 2001 as a potential Superfund site in part due to high levels of polycyclic aromatic hydrocarbons (PAHs) which readily absorb to coal and combustion by-products.
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