中国大中型气田天然气聚集效率及其主控因素

Gas accumulation efficiency and its main controlling factors in China's large and medium gas fields

付广 吕延防 于丹

Fu Guang Lu Yanfang Yu Dan

中国60余个大中型气田天然气地质储量、含气面积和成藏时期的统计结果表明,中国大中型气田的聚集效率差别很大。据此将中国大中型气田分为高、中、低效3种类型:高效大中型气田天然气聚集效率大于100×10m/(Ma·km);中效大中型气田天然气聚集效率为10×10～100×10m/(Ma·km);低效大中型气田天然气聚集效率小于10×10m/(Ma·km)。中国大中型气田天然气聚集效率主要受源岩生气强度、天然气输导速度、封盖能力和天然气成藏期相对早晚等因素的共同控制。即源岩生气强度越大,天然气输导速度越大,盖层封盖能力综合评价指标越大和天然气成藏时期越晚,天然气聚集效率越高;反之则越低。

Statistics of gas in place,gas-bearing area and reservoiring period of over 60 large and medium gas fields in China show that their accumulation efficiencies vary greatly.China's large and medium gas fields can be classified into 3 types,including high,moderate and low efficiency gas fields,according to their accumulation efficiencies.Gas accumulation efficiency of high efficiency gas fields is over 100?10 m /(Ma·km),that of moderate efficiency gas fields is in the range of 10?10-100?10 m /(Ma·km),and that of low efficiency gas fields is below 10?10 m /(Ma·km).The gas accumulation efficiencies of China's large and medium gas fields are mainly controlled by gas generating intensity of source rocks,gas delivery rate,sealing(ability)and timing of gas reservoiring period.The larger gas generating intensity,higher gas delivery speed,larger comprehensive sealing index of cap rocks(CSI),and later gas reservoiring period would lead to higher gas accumulation efficiency,and vice versa.

10.11743/ogg20050610