Date(s) - 02/18/2020
11:30 am - 1:00 pm
Bush Convention Center
Applying a Sequence Stratigraphic Model to Explain Stratigraphic Architecture and the Spatial Distribution of Reservoir Facies in the Mississippian Limestone
Jim Puckette, Keller Flinton and Mike Grammer, Boone Pickens School of Geology, Oklahoma State University
A primary task of the petroleum geologist is to integrate and evaluate all available core, mudlog, DST, and log data associated with a well to identify zones of interest likely to produce commercial hydrocarbons (“pay zones”). In the Permian Basin, the availability of core, mudlogs, and/or DSTs is a rare treasure, resulting in the reliance upon open hole well log data of various vintages as the primary tool for determining the presence of moveable hydrocarbons. Often this log analysis takes the form of calculating water saturation (Sw) from the Archie equation using standard parameters (a=1, m=2, n=2) and applying minimum porosity and maximum Sw cutoffs to flag potential pay zones.
However, log analysis in carbonate reservoirs can present unique challenges. When a carbonate reservoir has textures and pore types similar to the sandstones used to develop Archie’s equation (i.e., interparticle pores), the calculation of Sw from well logs is relatively straightforward. Yet carbonates are extremely susceptible to cementation and dissolution and often contain non-Archie pore types (e.g., intraparticle, vuggy, moldic, etc.), which may grossly violate the assumption of m=2 (if m>2, calculated Sw is lower than actual) and inherently possess a higher relative permeability to water. Without alternative methods to confirm the standard Archie Sw assumptions, porosity and Sw cutoffs alone are inadequate for differentiating between a profitable target and an uneconomic teaser.
To address these challenges, over the decades several authors have established empirical relationships and interpretation techniques that provide insight into the pore types present, predict the fluid produced, and better estimate Sw using common open hole log suites. The Carbonate Well Log and Core Analysis spreadsheet tool brings together many of these underutilized log analysis techniques advocated by Dr. George Asquith and others to rapidly screen and de-risk potential pay zones in carbonate reservoirs. When routine core data and/or capillary pressure data is also available, additional productivity insights can be gained by comparing log analysis results with core-derived saturations, reservoir quality indicators, height above free water level, etc. all within this integrated analysis tool.
Jim is Associate Professor and Geoscience Education Chair in the Boone Pickens School of Geology at Oklahoma State University. Jim specializes in physical stratigraphy and petroleum geology. Prior to joining the faculty in 2000, Jim was an exploration geologist working mostly in the northern and central Oklahoma. He is presently involved in studies of conventional and unconventional reservoirs including the Hunton Group, Caney Shale, Woodford Shale, Mississippian carbonates and Pennsylvanian sandstones and carbonates. In addition to his collegiate instruction and research, Jim is active in outreach through teacher training and presentations to school and youth groups. Jim thrives on field work and is the Director of the OSU Les Huston Field Camp near Cañon City, Colorado.
PBS-SEPM Luncheon Lecture: February 18th, 2020
Bush Convention Center 11:30am – 1:00pm
by February 14th
$25.00 pre-registered, $30.00 at the door