DEVELOPMENT AND APPLICATIONS OF NEW GEOCHEMICAL REFERENCE MATERIALS TO MAJOR U.S. UNCONVENTIONAL SHALE PLAYS

In 2015, the USGS embarked on a three-year project to develop geochemical reference materials (GRMs) sourced from major unconventional oil and gas plays in the continental United States. In collaboration with state and industry partners, materials from the Boquillas Formation (Eagle Ford equivalent), Mancos Shale, and Woodford Shale have been collected during the initial phase of the project. Additional collections from the Niobrara and Marcellus Formations are scheduled. The shale GRMs will be prepared as both traditional ground powders and coarse crushed materials to facilitate a wider range of sample preparation methods and chemical tests commonly used in core and cuttings analyses. These materials will be examined with specific focus on the effect of particle size on quantitative chemical analysis. Certified values for quantitative mineralogy (XRD-Rietveld) and chemical composition (major, minor, and trace elements) will be obtained through intra-laboratory collaboration. Certification efforts will also expand into the area of organic geochemical analysis by providing information from programmed pyrolysis and total organic carbon (TOC) analyses. The new GRMs are being collected in sufficient quantities to support the long term needs (10-20 years) of the petroleum industry and geochemistry community for matrix-matched materials to facilitate improved instrument calibration, testing, and quality control. Preliminary characterization results will be presented for materials collected in 2015 and the results of sampling trips, currently planned for July and August of 2016, will be discussed.