Research progress on tight oil exploration in China

The exploration and development of unconventional oil and gas become the hotspot in worldwide petroleum industry at present and in the future time. The unconventional resources are the succession and growth of conventional oil and gas production. Mineral resource investigations reveal that tight oil reservoirs in China contain highly geological and recoverable reserves, effective development of which is of great significance but restricted by poor reservoir physical properties and complex oil-water distribution. After decades of exploration and development, low and ultra-low permeability reservoirs have been successfully developed. However, development patterns and flow mechanisms suitable for tight oil are still insufficient, and the field application is far from mature yet. This study first summarized the resource distribution, geological characteristics, exploration, and development status of tight oil reservoirs in China. Then, development patterns and corresponding fundamental scientific issues of tight oil reservoirs were discussed. Corresponding nonlinear flow laws, mathematical flow models of multi-field and multiscale related to different exploitation patterns and scientific issues were summarized. Related study results of the authors were also introduced. Finally, a future development trend was proposed for each aspect. We hope that this study will provide some guiding to promote the tight oil exploration in China.