论南方海相层系有效供烃能力的主要控制因素

An Approach to the Main Controls on the Potential of Efficient Hydrocarbon Supply of Marine Sequences in South China

通过对烃源条件和天然气成藏过程的动力学分析,从高有机质丰度海相碎屑岩层段发育、构造沉积类型特征、高—过成熟阶段烃源灶性质演变形成的气源接替效应以及生烃强度与非构造性散失强度(速率)在地质历史中数量关系等若干方面,探讨了影响中国南方海相层系天然气成藏的有效供烃能力的主要地质-地球化学因素。指出有效供烃效率是烃源岩性质、构造-沉积类型、烃源灶类型及其叠合、生烃强度历史演化和天然气散失速率诸控制要素的综合效应。提出烃源条件分级评价指标,并对南方海相层系的有效供烃能力进行了初步评价。

Through dynamic analysis of the source kitchen and accumulative process, a couple of factors, such as development of organic rich marino clastic interval, type of tectonic-deposition, effect of source-consequence resulted from source kitchen evolution in high-over mature phases and the quantitative relationship of the intensities of hydrocarbon generation and non tectonic escape, were taken to understand the main geological and geochemical controls on the efficient hydrocarbon supply for the gas accumulation of marine sequences in south China. The capability of efficient hydrocarbon supply is one effect that integrates nature of source rock, type of tectonic-deposition, habit of source kitchen, the intensities of hydrocarbon generation and dissipation of gas through the time. The condition of hydrocarbon supply in the superposed basins of south China can be ranked as follow as： Excellent＇ with the efficient supply exceeding 20 × 10^8m^3/km^2,＇ Good＇ with the efficient supply up to 10 × 10^8 -20×10^8 m^3/km^2, ＇Moderate~ with the efficient supply up to 1 ×10^8 - 10 ×10^8 m^3/km^2 and ＇Poor＇ with the efficient supply less than 1 ×10^8 m^3/km^2. According to the criteria, a preliminary revalue was made to evaluate the capabilities of efficient hydrocarbon supply of the marine sequences in south China.