Utica Shale Study

Several members of our highly successful Marcellus Shale Project have encouraged Core Lab to initiate a similar project in the Utica Shale. The Utica Shale is an upper Ordovician-aged, calcareous, black shale that extends across the Appalachian Plateau from New York and Quebec, Canada, south to Tennessee. It therefore, underlies the Marcellus and extends farther west providing another shale reservoir target in Ohio, New York, Pennsylvania and West Virginia. The Utica Shale produces oil in Ohio and gas in the deeper portions of the basin to the east. In the near term, most activity is expected to be in the liquids-rich portion of the play in Ohio and western Pennsylvania.

Several companies are embarking on an evaluation of the Utica Shale and are planning pilot wells with the acquisition of cores. The Utica Shale has very different reservoir properties than the Marcellus and should be challenging in terms of 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 this reservoir. Therefore, in order to properly evaluate and explore this resource, 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 Utica Shale 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 Utica Shale. This project consists of the characterization and evaluation of numerous conventional cores, rotary sidewall cores, and drill cutting samples taken from multiple wells targeting the Utica Shale. Specifically, this prospective shale 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 these shale sections, but also on other operator's wells. The project will be focused on evaluating numerous Utica Shale wells in the Appalachian region.

Project Objectives

The primary objective of this project is to provide operators with measured geological, petrophysical, geomechanical, geochemical, and production properties of the Utica Shale in order to improve their formation evaluation and to optimize stimulation and production. Our work suggests that understanding the similarities and differences in these shales on a regional basis is the key to successful exploration and exploitation. The resultant database will be an invaluable tool to operators in evaluating, comparing, and designing completion and stimulation methods for the Utica Shale. Specifically, the project objectives are as follows:

• Geologically characterize the cored shales in terms of depositional facies, environment of deposition, and rock types.
• Characterize and classify the 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).
• Measure and characterize the organic content of the shales in terms of total organic content (TOC), Rock Eval pyrolysis, and maturity.
• Determine the gas desorption associated with kerogen and adsorption isotherm for gas storage capacity as a function of reservoir pressure (where appropriate).
• 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 Utica Shale properties.
• Integrate the core data with well logs, fracture stimulation techniques, and production test results to aid companies in their evaluation and exploitation of Utica reservoirs.
• Provide a regional assessment of the Utica Shale to aid in exploration and exploitation.
• Develop relationships from the database to aid in evaluating and comparing the various shale rock properties.
• Provide operators with a searchable database for Utica Shale properties that can be used as analogs to aid in the appraisal and exploitation of "unknown or newly discovered" Utica Shale reservoirs.