盆地深部地质作用与深层资源——科学问题与攻关方向

向地球深部进军是我国重要的资源战略,同时也是地质学科发展的重要方向。随着油气勘探认识和技术的不断进步,全球范围内深层-超深层已成为油气勘探开发的重点领域,更是中国常规油气勘探的主战场之一。我国许多含油气盆地中都发现了与深部地质作用相关的H2、He、CO2、地热等共伴生资源的规模聚集。因而,探究深部地质作用及其对深层资源的影响具有重要的意义。分析梳理了盆地深部地质作用对深层烃源岩生烃与演化、储层发育与保存、油气运移与聚集及油气共伴生资源富集的控制作用,总结了研究进展和面临的科学问题,提出了进一步科技攻关的方向。盆地深部地质作用与深层资源形成分布面临的主要科学问题有:深部地质作用下有机质成烃化学动力学与多元生烃潜力;深部高温高压超临界体系流体-岩石-烃类相互作用机理及超深层储层的有效性;深部油气系统中烃类相态转化、运聚成藏及保存机制;深部特殊地质环境下油气共伴生资源的形成与富集。深入开展深部地质作用与深层油气资源研究,需要从沉积盆地深部构造演化入手,围绕深部地质过程与资源效应这一核心科学问题,选择深部流体活跃的典型盆地为解剖对象,揭示深部层系物理化学作用机理,阐明不同深部地质过程对不同类型资源(油气、H2、CO2、He、地热及干热岩)形成与聚集的控制机制,探索深部资源新领域。未来的主要攻关方向包括:深部地质动力学背景与地质作用机制;深层生烃动力学与生烃量估算;深层储层发育与保持机理;深层油气运移与聚集机理;深层共伴生资源差异性富集机理。通过攻关,丰富完善盆地深部地质作用影响下油气富集理论与评价方法,也为深部其他战略性共伴生资源的评价与勘探提供科学依据。

Deep geological processes and deep resources in basins: scientific issues and research directions

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.