分散可溶有机质的气源意义

广泛分布在烃源岩及输导通道中的分散可溶有机质作为一种新的气源逐渐受到重视。分散可溶有机质成气不仅关系到原油的消耗,还关系到天然气的资源评价结果,因而定量评价这一过程对油气勘探有着重要意义。笔者总结对比了传统成烃模式与考虑分散可溶有机质成气模式的异同,建立了分散可溶有机质成气的地质模型,初步计算了塔里木盆地分散可溶有机质的成气量。指出分散可溶有机质这一气源使得地层成气区域突破了烃源岩的分布范围,成气中心向构造高部位偏移,成气期推迟。计算得到塔里木盆地分散可溶有机质成气模式中源内分散可溶有机质裂解成气与源外的比例为1∶2.88,在成气晚期白垩纪末至现今这一阶段油裂解成气量为799千亿m3,是传统油成气模式的4.23倍。

Significance of Dissipated Soluble Organic Matter as Gas Source

With the gradual deepening of the natural gas generation and migration mechanism,the dissipated soluble organic matter,which was residual in the source rock and migrated outside the source rocks and didn’t form the gathered oil and gas reservoirs in the evolutionary process of kerogen,is gradually getting more attention as a new gas source.The dispersed soluble organic matter into gas is not only related to the consumption of crude oil,but also related to the results of the natural gas resource evaluation,and thus the quantitative evaluation is of great significance to the oil and gas exploration.We summarized and compared the differences between traditional mode of hydrocarbon generation and the dissipated soluble organic matter into gas mode,and established a geological model of the dissipated soluble organic matter into gas,then gave a preliminary calculation of the dissipated soluble organic matter into gas in Tarim basin.And just because of the existence of this gas source,gas generation area is beyond the distribution range of hydrocarbon source rocks.Besides,for this reason, gas generation center migrates to high positions of structures and the period of gas generation is also been put off.By the calculation,the proportion of the dispersed soluble organic matter into gas in the Tarim basin between the source and outside source is 1 to 2.88.The volume of the oil-cracked gas, which is generated on the period between the Late Cretaceous and now days,is 799 hundred billion stere,which is 4.23 times of the traditional oil into gas mode.