气藏天然气输导效率研究

基于达西定律,利用天然气渗滤运移输导速度建立了一套气藏天然气输导效率的研究方法。以我国19个大、中型气田为例,对其天然气输导效率进行的研究结果表明,这些大、中型气田天然气输导效率差异较大,断裂输导的大、中型气田天然气输导效率明显高于砂体输导的大、中型气田的天然气输导效率,这主要是由于断裂渗透率和源岩-圈闭的垂直距离明显大于砂体渗透率和源岩-圈闭垂直距离的缘故。对我国19个大、中型气田天然气聚集效率与其输导效率之间关系的研究结果表明,高效大、中型气田形成所需要的天然气输导效率应大于1.96nm/s,中效大、中型气田形成所需要的天然气输导效率应为1.96~0.15nm/s,低效大、中型气田形成所需要的天然气输导效率应小于0.15nm/s。

Gas transporting efficiency analysis of gas reservoirs

The factors for influencing transporting capacity of natural gas flowing in transporting pathway were analyzed on the basis of Darcy's law.A series of methods for studying gas transporting efficiency of gas reservoirs were established by using gas transporting velocity.The gas transporting efficiencies of nineteen large-medium gas fields in China show that there is a great difference in gas transporting velocities of the different large-medium gas fields.The large-medium gas fields with fault transporting pathways have obviously higher gas transporting velocities than those with sand-body transporting pathways,because the large-medium gas fields with fault transporting pathways have bigger permeability of fault and vertical distance from source-rock to trap than those with sand-body transporting pathway.The relations between gas accumulation efficiency and gas transporting efficiency of 19 large-medium gas fields show that the required gas transporting efficiency for forming the high-efficiency large-medium gas fields is over 1.96 nm/s,and required gas transporting efficiency for middle-efficiency gas field is from 1.96 nm/s to 0.15 nm/s.The required gas transporting efficiency for low-efficiency gas field is less than 0.15 nm/s.