Abstract

Routine geochemical screening methods combined with advanced mineralogical and elemental stratigraphy data are integral to successful unconventional petroleum reservoir assessment and development. Advances in instrumental technology and field deployment strategies are shown to facilitate “near real time” acquisition of these data sets while drilling. Specifically, data obtained from drill cuttings and core chips are organic richness (TOC), thermal maturity parameters (Programmed Pyrolysis), weight percent of all rock-forming minerals including total abundance of clay (XRD) and weight abundance of 12 major elements and 19 trace elements (ED-XRF). These screening measurements are conducted on large numbers of samples to assess the distribution of reservoir characteristics across the zone of interest in the subsurface.

Along with a full investigation of the equipment, service and deliverables, we report selected results from wellsite screening of cuttings and whole core samples collected from both the vertical pilot and lateral sections of a Permian Basin well. The data acquired from the vertical pilot were used to identify the most attractive unconventional target by comparing individual geochemical assessments (organic content, thermal maturity, present day kerogen characteristics and available hydrocarbon content) of each organic-rich interval encountered. Mineralogy and elemental chemostratigraphy refined the target by screening for the best completions quality within the selected target interval. Elemental data obtained through the lateral section mapped the path of the wellbore through the stratigraphy by correlation to the vertical type log. Geochemistry, mineralogy and proxy brittleness data from the lateral section mapped the lateral heterogeneity of the wellbore for customized completions design. Comparisons of these key rock properties to completions notes and other performance audits on a well, stage or cluster basis can improve future drilling and completions plans.