Brett J Valentine

Investigating the effects of broad ion beam milling to sedimentary organic matter

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%...

Categories: Data; Tags: Bituminous Coal, Broad Ion Beam, Coal resources, Energy Resources, Geochemistry, All tags... Ion Milling, Pennyslvania, Sedimentary Organic Matter, Thermal Maturity, USGS Science Data Catalog (SDC), Vitrinite reflectance, Fewer tags

TOC, Reflectance and Raman Data from Eocene Green River Mahogany zone

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...

Categories: Data; Tags: Anhydrous pyrolysis, Colorado, Energy Resources, Garfield County, Geochemistry, All tags... Hydrous pyrolysis, Organic petrography, Petroleum generation, Raman spectroscopy, Rifle, Solid bitumen, Solid bitumen reflectance, Thermal maturity, USGS Science Data Catalog (SDC), Fewer tags

Textural occurrence and organic porosity of solid bitumen in shales

This study presents Raman spectroscopic data paired with scanning electron microscopy (SEM) to assess solid bitumen composition and porosity development as a function of solid bitumen texture and association with minerals. A series of hydrous pyrolysis experiments (1-103 days, 300-370°C) using a low maturity (0.25% solid bitumen reflectance, BRo), high total organic carbon [(TOC), 14.0 wt. %] New Albany Shale sample as the starting material yielded pyrolysis residues designed to evaluate the evolution of TOC, solid bitumen aromaticity, and organic porosity development with increasing temperature and heating duration. Solid bitumen was analyzed by Raman spectroscopy wherein point data was collected from accumulations...

Categories: Data; Tags: Clegg Creek, Energy Resources, Geochemistry, Hicks Dome, Hydrous pyrolysis, All tags... Illinois, Indiana, Organic petrology, Organic porosity, Raman spectroscopy, Thermal maturation, USGS Science Data Catalog (SDC), Fewer tags

Evaluation of pore-like features in sedimentary organic matter

Research examining organic-matter hosted porosity has significantly increased during the last ten years due to greater focus on understanding hydrocarbon migration and storage in source-rock reservoirs, and technological advances in scanning electron microscopy (SEM) capabilities. The examination of nanometer-scale organic-matter hosted porosity by SEM requires the preparation of exceptionally flat geologic samples beyond the abilities of traditional mechanical polishing which can deform or otherwise obscure organic surfaces. To meet this demand, broad ion beam (BIB) milling was introduced as a sample preparation technique for SEM petrographic analysis of geologic samples. But like with any sample preparation technique,...

Categories: Data; Tags: Colorado, Energy Resources, England, Geochemistry, USGS Science Data Catalog (SDC), All tags... Utah, broad ion beam milling, organic matter, pore-like features, preparation artifacts, solid bitumen, Fewer tags

Oil-source rock correlation studies in the unconventional Upper Cretaceous Tuscaloosa marine shale petroleum system, Mississippi and Louisiana, USA (2019)

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...

Categories: Data; Tags: Amite County, Biomarkers, East Feliciana County, Energy Resources, Franklin County, All tags... Lincoln County, Louisiana, Mississippi, Oil shale resources, Pike County, Saint Tammany County, USGS Science Data Catalog (SDC), Wilkinson County, petroleum geochemistry, thermal maturity, Fewer tags