Analysis of Liquid Resource Play Potential in China

The overwhelming impact of unconventional exploration in the United States of America has sparked global interest in the development of shale resource plays. In China, although shale gas exploration has been a key focus in the past five years, particularly in the Sichuan Basin, potential for liquid unconventionals is high; the country was ranked third in global potential shale oil resources by the Energy Information Administration in 2013. The success of any unconventional play is dependent on the characteristics of the targeted sediment package, which are controlled by regional geology, stress regime, and thermal maturity. This study integrates publically available depositional, tectonic and geochemical information and uses a biostratigraphically-constrained sequence stratigraphic model to assess liquid-rich resource play potential across China, high-grading key formations and analysing the impact of tectonics upon prospectivity. Structural cross sections and vitrinite reflectance data are utilised to constrain the depth of the paleo-oil window across the Sichuan, Ordos, Junggar, and Bohaiwan basins. Oil-mature formations are then assessed for unconventional potential based upon burial depth, thickness, Rock Eval parameters, vitrinite reflectance (vRo), rock properties and gross environment of deposition. The effect of tectonics upon thermal maturity is shown to play a key role in the spatial distribution of possible pseudo-"sweet spots"; in the Junggar and Santanghu basins, where Permian shales are candidates for exploration, prospectivity is dependent on burial depth and preservation. The study also draws comparisons between lacustrine shales in China, Australia, Brazil, South Africa and the U.S. The iterative workflow presented in this study allows temporal and spatial high-grading of shale deposits for liquid unconventional potential, and it is therefore a powerful tool to aid future unconventional exploration across China and other data-poor regions.