塔里木盆地S74井稠油热模拟实验研究(二)——沥青生烃潜力探讨

THERMAL SIMULATION OF HEAVY CRUDE OIL FROM WELL S74 IN THE TARIM BASIN(Ⅱ)——HYDROCARBON GENERATING POTENTIAL OF BITUMEN

根据塔里木盆地S74井稠油热模拟实验中油气产率、模拟产物地球化学特征探讨了降解-氧化沥青的产烃率模式。研究表明,降解-氧化沥青生烃作用主要发生于生油窗内,高成熟演化阶段也有一定的生烃潜力,过成熟演化阶段生烃潜力有限;在产物组成上,350℃(Ro=1.24%)之前以生油为主,产油率约245 kg/t,而之后则以生气为主。据降解-氧化沥青产烃率模式,对塔里木盆地沙雅隆起、卡塔克隆起志留系沥青砂岩生烃量的粗略估算表明,其生烃量巨大,可能是塔里木盆地海西晚期及以后的重要油源。

The hydrocarbon productive rate of the degradation-oxidant bitumen were discussed based on the geochemical characteristics of the simulation products and the hydrocarbon productive rate at various simulation temperature points of the heavy crude oil from Well S74 in the Tarim Basin. The results indicated that hydrocarbon-generation of the degradation-oxidant bitumen was mainly taken place in the oil- generating window, in other word, oil was mainly generated when Ro was not larger than 1.24%（T= 350 ℃）, with its oil productive rate of 245 kg/t. There also was some hydrocarbon-generating potential in the highly-matured bitumen, but almost no hydrocarbon-generating potential in the over-matured bitumen. Their products were mainly alkane gas. According to above model, hydrocarbon generation amount of the Silurian bitumen sandstones in the Shaya and the Katake Uplifts was calculated. It showed that the generated hydrocarbon was magnitude and probably was one of important sources for hydrocarbon accumulations since the Late Hercynian in the Tarim Basin.