More Informed Drilling and Completions Through Advanced Cuttings Analysis at Wellsite
May 23, 2015
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 over 20 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 organicrich 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 identified 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 will improve future drilling and completions plans.