摘要
塔中地区发育中—上奥陶统和中—下寒武统两套主力碳酸盐岩烃源岩层,热演化程度已达高—过成熟阶段。基于烃源岩演化过程中物质平衡原理恢复塔中地区深层烃源岩在未排烃前的原始总有机碳含量值,并用恢复后的总有机碳含量值、厚度、面积对烃源岩有效性进行重新评价。结果表明,塔中地区深层碳酸盐岩烃源岩的恢复系数约为2.5;用恢复后的总有机碳含量将塔中深层碳酸盐岩有效烃源岩的TOC下限值重新拟定为0.2%;有效烃源岩的平面分布范围从10×10~4km^2扩大到17×10~4km^2,厚度由14~149m增加到61~278m,根据塔中地区新的有效烃源岩判别标准确定出的排烃量增加了1.52倍,总资源量增加了1.62倍,表明塔中地区深部低总有机碳含量烃源岩对油气成藏的贡献不应被忽视。
There are two sets of carbonate hydrocarbon source rocks that lie in middle-upper Ordovician and middle-lower Cambrian,their thermal evolution degrees have reached to high or over mature stage.Based on the principle of material balance in the evolution process of deep hydrocarbon source rocks to recover the original TOC before hydrocarbon expulsion in central Tarim basin,by which the effectiveness of hydrocarbon source rock has been reevaluated in terms of its thickness and area.Results showed that the recovery coefficient of hydrocarbon source rocks in deep carbonate was 2.5 in central Tarim basin,the TOC low limit of effective hydrocarbon source rocks redrafted as 0.2% by recovered TOC in central Tarim basin,the plane distribution of effective hydrocarbon source rocks ranges from 10× 10^4km^2 to 17× 10^4km^2,average thickness increased from 81.5m to 169.5m;the amount of hydrocarbon expulsion confirmed by new identifying standard of effective hydrocarbon source rocks raised 1.52 times in central Tarim basin,total resource amount increased 1.62 times,which indicated that the contribution of low TOC of deep hydrocarbon source rocks should not be ignored in central Tarim basin.
出处
《非常规油气》
2016年第4期48-57,共10页
Unconventional Oil & Gas
基金
国家重点基础研究发展计划(973)项目(2011CB201102)
关键词
塔中地区
深层
碳酸盐岩烃源岩
烃源岩总有机碳含量恢复
有效烃源岩判别
Central Tarim basin
deep carbonate
hydrocarbon source rock
TOC recovery for hydrocarbon source rocks
effective source identification of hydrocarbon source rock
