Eaglebine – Regional Study

Reservoir Characterization and Production Properties

Currently, numerous oil and gas companies are directing their efforts toward the exploration and exploitation of the “Eaglebine” section in East Texas. The “Eaglebine” section is the interval from the base of the Austin Chalk to the top of the Buda limestone. It consists of the Woodbine sandstones and the underlying Eagle Ford Shale both of which are targets for horizontal completions. These liquids-rich reservoirs have proved to be challenging in terms of drilling, reservoir characterization, predicting producibility potential, estimating ultimate recovery, and optimizing fracture stimulation techniques. Many companies either do not have or have limited rock property data that are crucial for understanding these reservoirs. Therefore, in order to properly evaluate and explore these gas and oil producing reservoirs, appropriate types of rock property data need to be measured and integrated with log data, stimulation techniques, and production test information. These integrated data sets and case histories will provide operators with the critical parameters to optimize their exploitation of the “Eaglebine” and reduce finding and development costs.

The Integrated Reservoir Solutions Division of Core Laboratories is proposing to interested companies participation in a multi-company, geo-engineering study of the “Eaglebine” reservoirs. The project is an extension of our highly successful Eagle Ford Shale study of South Texas and our Woodbine Sandstone study of East Texas. The project consists of the characterization and evaluation of numerous conventional cores, rotary sidewall cores, and drill cutting samples taken from multiple wells targeting the “Eaglebine” section. Specifically, this prospective section will be analyzed for geological, petrophysical, geomechanical, geochemical, and production properties. These data will be integrated with well logs, stimulation designs, and production test information. This large and searchable database will provide operators with valuable information not only on their own wells within the section, but also on other operator’s wells.

Project Objectives

  • Geologically characterize the cored intervals in terms of depositional facies, environment of deposition, and rock types.
  • Characterize and classify the Woodbine sandstones and Eagle Ford shales in terms of lithology, mineralogy, clay content, clay types, and pore structure including macro- and micro-fractures.
  • Measure the various petrophysical properties such as porosity, permeability, grain density, and saturations (i.e. water saturation, gas saturation, mobile oil saturation, gas-filled porosity and bound water). In addition, electrical properties, capillary pressure and effective permeability to oil will be determined for the Woodbine sandstone rock types.
  • Measure and characterize the organic content of the Eagle Ford shales in terms of total organic content (TOC), Rock Eval pyrolysis, and vitrinite reflectance.
  • Measure the key geomechanical properties that are required for optimizing fracture designs and/or horizontal wells such as Young’s Modulus, Poisson’s Ratio, Bulk Modulus, fracture conductivity, horizontal stress, and proppant embedment.
  • Core-log calibration of open-hole logs for the development of petrophysical models to determine “Eaglebine” reservoir properties.
  • Determine the cause and remedy for drilling problems operators are having in the section.
  • Integrate the core data with well logs, fracture stimulation techniques, and production test results to aid companies in their evaluation and exploitation of “Eaglebine” reservoirs.
  • Provide a regional assessment of the “Eaglebine” to aid in exploration and exploitation.
  • Develop relationships from the database to aid in evaluating and comparing the various rock properties.
  • Provide operators with a searchable database for “Eaglebine” reservoir properties that can be used as analogs to aid in the appraisal and exploitation of unknown or newly discovered “Eaglebine” reservoirs.
  • Available in RAPIDLink™