Roles of gypsum/salt-bearing sequence in hydrocarbon accumulation and storage
Wenhui Liu, Yining Li, Quanyou Liu, Xiaofeng Wang, Qingqiang Meng, Dianwei Zhang, Longfei Lu, Houyong Luo
Abstract
Gypsum/salt beds are widely developed in petroliferous basins across the world. Most basins with gypsum/salt beds have been proven to host abundant hydrocarbon resources. Previous studies on the effects of gypsum/salt beds on hydrocarbon reservoirs primarily focused on their excellent sealing property as cap rocks. However, an increasing number of exploration discoveries have shown that gypsum/salt beds have the potential to promote the formation of high-quality source rocks and hydrocarbon reservoirs. Gypsum/salt beds influence the generation, preservation and accumulation of hydrocarbons. Based on the systematic analysis of the generation of hydrocarbons in global gypsum/salt-bearing sequences, the study discussed the control of gypsum/salt beds on play elements, and explore the relationship between the development of gypsum/salt beds and global large- and medium-scale hydrocarbon reservoirs. Furthermore, we analyzed the correlation between typical gypsum/salt-bearing sequences and their hydrocarbon generation potentials in China. In-depth analysis shows three patterns in terms of the spatial superimposition of gypsum/salt beds and source rocks, that is, post-salt pattern, inter-salt pattern and pre-salt pattern. Among others, the source rocks of the inter-salt pattern are widely developed in salt basins and of great potential for hydrocarbon exploration.