Integration of Detailed Geologic Study with Log-Based Rock Classification Helps Define the Regional Geologic Setting of the Haynesville and Bossier Shale Plays

Marino, Sonia; Herring, Shanna; Stevens, Kimberly; Handwerger, David; Suarez-Rivera, Roberto

A detailed geologic study of the Haynesville and Bossier plays using multiple cores was conducted, with core samples selected to determine the lateral variability of these plays over an area of 8,000 square miles. The study was supplemented with comprehensive core characterization that included measurements of petrologic, geochemical, petrophysical and mechanical properties across all facies. The study defined the subtle variability in reservoir quality of geologic facies based on the various sources of mineral and organic input, biotic activity and changes in the environmental setting during deposition, including diagenetic transformations. This work was integrated with high-resolution, log-based, classification that identified rock classes with similar texture and composition. A strong relationship between these rock classes with unique texture and composition properties, defined by log measurements, and the geologic facies recognized by the original study was established. Its validity was demonstrated by comparing log predictions with observation on additional cores, not used in the initial study. The resulting log-based model allowed the propagation of the geologic properties across the play, in a quantitative manner, using logs. It also allowed us to understand the lateral variability in reservoir quality across the two plays. Results were subsequently validated by verifying consistency with the broad geologic setting and comparison to cores. Among the most important results of the study was the identification of Haynesville quality rock, with high reservoir potential, in regions of the Bossier play. Tracking the extent of this Bossier facies geographically, using logs, is of fundamental importance for early exploration and development success in this play. Another important result was the geographic delineation of a region with overall best reservoir quality in the Haynesville play.

Integrating geology with rock classes of unique combinations of texture and composition and with their associated material properties provides optimized field development. In addition, while cores and seismic surveys often exist in isolated locations, this method of quantitative geologic extrapolation with logs provides high resolution information for selecting the most strategic locations for additional cores and supplemental seismic data. This results in a highly effective exploration effort that maximizes value.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013