天然气成藏过程的地球化学示踪研究现状

Research situation of geochemical tracing in the formation process of natural gas reservoirs

天然气成藏过程的地球化学示踪研究,即利用天然气残留的地球化学信息,反演其生成、运移、聚集和保存的动态过程,以确定其来源、资源前景和分布规律,并提供有利的勘探目标。通过数十年的研究,中外地球化学家提出了多种类型的示踪指标,并对各类指标在天然气生成、运移、聚集及保存等成藏过程中的行为有了一定的认识:天然气烷烃组分、稳定同位素、轻烃及稀有气体是天然气源对比、重塑运聚成藏过程的有效指标,它们共同构成了天然气成藏示踪的指标体系;初步揭示了天然气组分组成、同位素组成等指标在不同阶段成藏的动力学变化规律,成为利用指标重塑天然气成藏过程的依据。在总结已有成果的基础上,结合目前研究中与地质背景结合少、机理与定量化研究程度低、混源成藏及散失过程研究薄弱等问题,认为天然气成藏过程的地球化学示踪应加强地质条件分析、物理模拟与数理模型建立、混源成藏及散失过程示踪方面的研究。

Geochemical tracing is researched in the formation process of natural gas reservoir. The residual geochemical information of the natural gas can be used to invert the dynamic process of generation,migration,accumulation and preservation. And then source,resource prospect and distribution law and exploration target of the natural gas could be known. After ten years of work,geo-chemists have given many kinds of tracing parameters,and transformation laws of majority of these parameters at every stage,from generation to preservation of natural gas reservoir formation have been discovered. Paraffin hydrocarbons component,stable i-sotopic,light hydrocarbon and rare gas are the effective indexes of gas-source correlation of the natural gas and migration-accumulation process rebuilding. They make up of the index system of tracing on natural gas reservoir forming. Dynamic transformation laws of natural gas component and isotopic composition at different stages of reservoir formation have been applied in re-establishing reservoir forming process. After analyzing the current status of geochemical tracing research,some insufficiencies,such as geological conditions investigation,mechanism and quantitative a-nalysis,mixed source reservoir forming and loss process,were pointed out. Aim at these insufficiencies,the research direction was brought forward.