David R. Spain

Integration of depositional, petrophysical, and petrographic facies for predicting permeability in tight gas reservoirs

AbstractUnderstanding the linkages between grain mineralogy and diagenetic and sedimentary processes enhances the reliability of petrophysical models to predict reservoir deliverability from permeability. Petrographic data within well-defined depositional facies reveal the diagenetic evolution of porosity-permeability relationships. Formation evaluation methods relying solely on petrophysical rock typing are seriously limited when predicting ultimate reservoir performance in complex pore structures. The Almond Formation, Wyoming, is characterized by three depositional facies associations — shoreface, deltaic (bay head and flood tide), and fluvial-coastal plain — which present three distinctive porosity-permeability trends. Textural features resulting from depositional processes, such as grain size and sorting, vary little between facies associations, yet permeability can vary by up to four orders of magnitude for the same porosity value. Differences between petrophysical facies are primarily driven by dia...

Multidisciplinary approach in determining the best zone to land a Haynesville horizontal well

AbstractThe Upper Jurassic Haynesville Shale Formation in the East Texas Basin, North America, is a black, organic-rich, calcareous mudstone that lies below the Bossier Shale and above the Cotton Valley Limestone. The reservoir quality was controlled by primary depositional process and secondary diagenesis. The best lithology type in terms of drilling, completion, and production is the organic-rich, silty calcareous mudstone with low clay content. The studied well traversed the entire Haynesville Formation with the objective to assess the production potential of this formation. We acquired open-hole, triple-combo logging while drilling (LWD) logs, two types of production logs, and regional microseismic data. Postdrill log modeling confirmed that the horizontal well stayed on the planned trajectory, based on the log correlation between the horizontal and offset wells. Log modeling demonstrated that the LWD resistivity logs in horizontal wells are subject to resistivity anisotropy and polarization horn effe...