This article aims to give an outline of an integrated geoscience approach that may apply in the initial identification of the shale play, address complex unconventional reservoirs, their associated challenges and finalise the pilot vertical wells to evaluate their potential.
Shale exploration depends on the proven source rock within the basin, so the availability of the required data, well data and seismic data in public domain for initial study and basin screening is usually easy. The investigation may start after knowing the well developed proven source rock in the basin. An extensive study of structure, tectono-stratigraphy, source rock and reservoir characterization, thermal maturity models and exploration strategy is required by using the regional tectonic history, drilled wells with multiple penerations in source rock, open-hole logs, mud samples and cores of the source rock to get the answers to the critical questions on the attributes that influence shale plays. Once these attribute questions have been satisfactorily confirmed to be in the required range or with an analog, that data can be utilized to locate possible sweet spots to drill pilot vertical wells with the goal of acquiring extensive coring, open hole logging and formation pressure testing data to identify the best candidates for further horizontal well evaluation.
This article highlights and demonstrates a possible step by step workflow for the selection of the shale play area, sweet spot and pilot vertical wells locations by using the schematic data maps, published material examples and building possible cut offs essential for exploration decision process.