油气成藏动力学研究之我见

Understandings on Dynamical Studies of Hydrocarbon Migration and Accumulation

油气成藏过程的动力学研究一直是石油地质学的核心内容。干酪根晚期热降解成油学说的提出及成功应用奠定了现代石油地质学的基础,人们开始真正从油气的生成出发,系统地考虑油气生成、排出、运移、聚集成藏的过程,分析油气成藏的基本要素(烃源岩,储集层,盖层,排烃,运移,圈闭及保存条件),并从盆地形成演化的角度研究油气运移过程中的相态、动力、阻力、通道、方向、距离、时间等特征,恢复油气成藏的过程。20世纪80年代以来,盆地流体流动机制、流动样式、溶质运移和流体—岩石相互作用及其成藏(矿)效应等方面的重要进展及定量方法的飞速进步极大地促进了油气成藏过程的动力学研究。油气成藏动力学研究是石油地质学研究发展的必然,是对油气运聚成藏的地质条件、影响因素、动力条件及演化过程等的定量表征和分析。油气成藏动力学研究应该以一期油气成藏过程中从油气源到油气藏的统一动力环境系统为单元,定量研究油气供源、运移、聚集的机理、控制因素和动力学过程;应重点关注油气成藏的时间、油气运聚的动力特征/背景及其演化、油气运聚的通道格架及其演化,实现运聚动力与通道的耦合,展现油气运移的路径特征、运移方向及运移量。

Dynamically studying the accumulation of hydrocarbons in traps has always been the core content of petroleum geology. Successful applications of kerogen theory in researches and exploration established a solid base of modern petroleum geology. Since then, the factors and processes that control and influence hydrocarbons formation and concentration have been systematically studied, source rock and hydrocarbon generation, expulsion and migration, reservoir and seal, trap formation and hydrocarbon accumulation, etc. The dynamical behaviors of hydrocarbons accumulation in the duration of basin evolution, including fluid phase, driving force and resistance, path and sealing, direction and distance, as well as time etc. , haste been studied over the past century. Since the 1980s, important progresses on geofluids and on calculating techniques make it possible to study dynamically and quantitatively the migration and accumulation of hydrocarbons in sedimentary basins. The progresses on geofluid researches include mechanisms and regimes of fluids flowing in basins, migration and transportation of materials, correlation between fluids and rocks as well as their mineralization. Dynamical studies on migration and accumulation of hydrocarbon represent the developing direction of modern petroleum geology, which characterizes and analyzes quantitatively the geological background and conditions, influences, driving forces, and migration-accumulation processes of oil and gas. In methodology, all these researches should be synthesized in a concept of migration-accumulation system. Such a system should consist of all the factors and processes and be characterized by unitary hydro-dynamical environment in the course of migration and accumulation. The dynamical studies should be based on the achievements of traditional petroleum geology and petroleum system, and therefore focus on mechanisms of hydrocarbon offering, migrating and accumulating, as well as the influences and forces. The keys to establish such a system include the timing of migration and accumulation, hydrodynamical background, carrier characteristics, and the coupling of migration driving forces and resistances. The results of the studies, such as pathways＇ distribution, migration directions and migration quantity, etc. ,should be quantitatively mentioned.