Shiyou shiyan dizhi (Sep 2020)
Deep geological processes and deep resources in basins: scientific issues and research directions
Abstract
Marching deeper into the earth is of great significance for domestic resource strategy and tends to be an inevitable research direction in geoscience. With theoretical and technological progress achieved in recent years, hydrocarbon resources in deep or ultra-deep reservoirs have become a major exploration field for targets at home and abroad. Various discoveries of large-scale geological resources, such as H2, He, CO2 and geothermal resources, are proved to be related to deep geological processes, and therefore it is important to reveal the impact of these on deep accumulations. In this paper, the effects of basinal deep processes on hydrocarbon generation and evolution of source rocks, formation and preservation of reservoirs, migration and accumulation of hydrocarbon and its associated resources were discussed. Besides, some research progress and key scientific issues were summarized, and subsequently several research directions were proposed. Presently main scientific issues regarding deep geological processes and deep resources include: a) chemical kinetic models and multiple hydrocarbon generation potential of source rocks in deep geological processes; b) interaction mechanism of water-rock-hydrocarbon in high-pressure and high-temperature supercritical systems and effectiveness of ultra-deep reservoirs; c) phase transformation, accumulation and preservation of hydrocarbon in deep oil and gas systems; d) generation and accumulation of hydrocarbon-associated resources in specific deep geological environments. To carry out research on deep geological processes and deep hydrocarbon resources, it is necessary to start with the geological evolution of sedimentary basins, centering on the key issues of deep geological processes and resource effects and taking typical basins with active deep fluids as research objects, and revealing the mechanism of physical and chemical functions of deep formation, finally clarifying the impact of deep geological processes on the formation and accumulation mechanism of deep resources (oil and gas, H2, CO2, He, geothermal resources and hot dry rocks) and exploring the frontiers of deep resources. The main research directions in the future include: a) deep geodynamic settings and mechanism of geological processes; b) deep hydrocarbon generation kinetics and quantities; c) formation and preservation mechanisms of deep reservoirs; d) migration and accumulation mechanisms of deep hydrocarbons; e) differential enrichment mechanism of deep hydrocarbon-associated resources. Based on the above research, the accumulation theories and evaluation methods of hydrocarbon under the influence of deep geological processes were improved, and some scientific evidence for the exploration and evaluation of deep hydrocarbon-associated resources were provided.
Keywords
