INTEGRATION OF MECHANICAL STRATIGRAPHY WITH LITHOFACIES IN GOLDWYER SHALE FOR SELECTING PRODUCIBLE AND HYDRAULIC FRACTURING LAYERS

The heterogeneous nature of ultra-low permeable unconventional gas shale reservoirs makes its evaluation very challenging. Therefore, the mechanical stratigraphic classification can help in finding suitable intervals for hydraulic fracturing. There are different options available for rock mechanical characterization-we have developed and implemented a new protocol we refer to as empirical shale mechanics. It integrates petrography, petrophysics and rock mechanics to determine mechanical rock types that are linked to the reservoir properties and depositional lithofacies. This protocol measures the basic static elastic parameters, rock strength and frictional properties. Additional properties derived from rock mechanical test such as deformation brittleness and elastic anisotropy (the difference between vertical and horizontal Young's modulus). Using the above approach, we build a mechanical stratigraphic model of vertical Theia-1 well in the Goldwyer-III unit of Ordovician Goldwyer shale formation. K-Means clustering algorithm is chosen to identify four mechanical clusters (clusters1-4) based on petrophysical logs and geomechanical properties. These clusters and reservoir properties (TOC, porosity and water saturation) are interlinked with four identified lithofacies (Argillaceous, Siliceous, Calcareous and Mixed shales) of the same unit. Combination of these two approaches reveal that siliceous and mixed shales have highest gas prospect along with best quality for generating multidirectional fracture networks.