The importance of the formation and fracture pressures for the selection of the depths for casing setting in Slovakia

Abstract

The successful development of shale gas requires a fundamental understanding of shales and that can be challenging because these rocks vary significantly. For recoverable shale gas resources assessment a broad range of geological, geochemical, geophysical and geomechanical data is required. Information about the variable lithologies, mineralogies, and kerogen content is vital to locate favorable intervals for gas production. Knowledge of the in-situ stresses and porosity of these intervals is essential for developing hydraulic fracturing strategies to recover the gas in place. Geomechanical properties of shales are important in terms of determination of the likelihood of fractures initiating and propagating in shale materials. Geomechanical properties of rock include: Poisson's Ratio, Total Minimum Horizontal Stress, Bulk, Young and Shear Modulus. These properties play significant role in developing shale assets. Having access to geomechanical data can assist engineers and geoscientists during geomechanical modeling, hydraulic fracture treatment design and in some cases during reservoir modeling in shale gas fields. This paper is intended to give characterization of geomechanical properties of shale rock. It then refers to a case study of Baltic Basin of shale gas in Poland, for discussing it geological condition and rock properties.