克拉通盆地高效大中型气田形成的天然气保存条件

Gas preservation conditions required in forming large-medium gas fields with high efficiency in Cratonic basin of China

在我国克拉通盆地16个大中型气田天然气保存特征分析的基础上,对大中型气田天然气保存条件、天然气聚集效率,以及天然气聚集效率和天然气保存条件综合评价参数之间关系进行了研究.结果表明:天然气保存条件存在着差异性,最大值与最小值之间相差200余倍;天然气聚集效率也存在差异性,最大值与最小值之间相差300余倍;天然气聚集效率和天然气保存条件之间呈正比关系,即天然气保存条件综合评价参数越大,天然气聚集效率越高;反之,则越低.我国克拉通盆地高效大中型气田形成所需要的天然气保存条件综合评价参数为175.3MPa·m·Ma-1.

Based on the analysis of gas preservation characteristics of 16 large-medium gas fields in Cratonic basin of China, by defining and calculating a comprehensive parameter and evaluating gas preservation conditions, gas preservation conditions of 16 large-medium gas fields in Cratonic basin of China were evaluated. The results show that there is a difference of gas preservation conditions in 16 large-medium gas fields of Cratonic basin. There is about 200 times difference between maximum and minimum. By the study of the gas accumulation efficiency of 16 large-medium gas fields in Cratonic basin of China, there is a difference of gas accumulation efficiency of 16 large-medium gas fields of Cratonic basin, there is about 300 times difference between maximum and minimum. By the study of the relation between gas accumulation efficiency and comprehensive parameter evaluating gas preservation condition of 16 large-medium gas fields, it shows that there is a direct relation between them, the bigger comprehensive parameter evaluating gas preservation conditions is, the higher gas accumulation efficiency is, the smaller comprehensive parameter evaluating gas preservation conditions is, the lower gas accumulation efficiency is. According to this, the limit value of comprehensive parameter evaluating gas preservation condition required in formation large-medium gas fields with high, efficiency in Cratonic basin of China is more than 175.3 MPa·m·Ma-1.