The lithology, lithofacies, reservoir properties and shale oil enrichment model of the fine-grained sedimentary system in a lake basin with terrigenous clastics of large depression are studied taking the organic-rich ...The lithology, lithofacies, reservoir properties and shale oil enrichment model of the fine-grained sedimentary system in a lake basin with terrigenous clastics of large depression are studied taking the organic-rich shale in the first member of Cretaceous Qingshankou Formation(shortened as Qing 1 Member) in the Changling Sag, southern Songliao Basin as an example. A comprehensive analysis of mineralogy, thin section, test, log and drilling geologic data shows that lamellar shale with high TOC content of semi-deep lake to deep lake facies has higher hydrocarbon generation potential than the massive mudstone facies with medium TOC content, and has bedding-parallel fractures acting as effective reservoir space under over pressure. The sedimentary environments changing periodically and the undercurrent transport deposits in the outer delta front give rise to laminated shale area. The laminated shale with medium TOC content has higher hydrocarbon generation potential than the laminated shale with low TOC content, and the generated oil migrates a short distance to the sandy laminae to retain and accumulate in situ. Ultra-low permeability massive mudstone facies as the top and bottom seals, good preservation conditions, high pressure coefficient, and lamellar shale facies with high TOC are the conditions for "lamellation type" shale oil enrichment in some sequences and zones. The sequence and zone with laminated shale of medium TOC content in oil window and with micro-migration of expelled hydrocarbon are the condition for the enrichment of "lamination type" shale oil. The tight oil and "lamination type" shale oil are in contiguous distribution.展开更多
松辽盆地中央坳陷上白垩统嫩江组是一套分布面积广、厚度大、富含有机质的低熟页岩层系。根据测井资料和岩心实测数据,研究页岩有机质丰度和类型的空间非均质性,据此建立地质模型,并基于生烃动力学和热传导模型,对研究区电加热原位改质...松辽盆地中央坳陷上白垩统嫩江组是一套分布面积广、厚度大、富含有机质的低熟页岩层系。根据测井资料和岩心实测数据,研究页岩有机质丰度和类型的空间非均质性,据此建立地质模型,并基于生烃动力学和热传导模型,对研究区电加热原位改质资源潜力进行预测。嫩江组各段总体上处于未成熟—低成熟阶段,是以生油为主的烃源岩。嫩江组一、二段古水体为淡水—微咸水,生烃母质主要为藻类体,有机质类型以Ⅱ1—Ⅱ2型干酪根为主,其中嫩一段烃源岩综合品质最好,优质烃源岩主要分布在长岭凹陷新北—大安地区。通过原位电加热模拟可以推断,2 k W加热功率下,页岩温度上升迅速,在加热4年后温度可达到600℃以上;1 kW加热功率下,则需要约8年。有机质转化率在加热到第五年时已经接近100%,达到原位改质最大资源丰度;加热至第五年末,在2 kW功率下,嫩一段页岩可产生的页岩油资源量为245.02×10^8t,嫩二段为65.89×10^8t。展开更多
基金Supported by the National Natural Science Foundation of China(41972156)。
文摘The lithology, lithofacies, reservoir properties and shale oil enrichment model of the fine-grained sedimentary system in a lake basin with terrigenous clastics of large depression are studied taking the organic-rich shale in the first member of Cretaceous Qingshankou Formation(shortened as Qing 1 Member) in the Changling Sag, southern Songliao Basin as an example. A comprehensive analysis of mineralogy, thin section, test, log and drilling geologic data shows that lamellar shale with high TOC content of semi-deep lake to deep lake facies has higher hydrocarbon generation potential than the massive mudstone facies with medium TOC content, and has bedding-parallel fractures acting as effective reservoir space under over pressure. The sedimentary environments changing periodically and the undercurrent transport deposits in the outer delta front give rise to laminated shale area. The laminated shale with medium TOC content has higher hydrocarbon generation potential than the laminated shale with low TOC content, and the generated oil migrates a short distance to the sandy laminae to retain and accumulate in situ. Ultra-low permeability massive mudstone facies as the top and bottom seals, good preservation conditions, high pressure coefficient, and lamellar shale facies with high TOC are the conditions for "lamellation type" shale oil enrichment in some sequences and zones. The sequence and zone with laminated shale of medium TOC content in oil window and with micro-migration of expelled hydrocarbon are the condition for the enrichment of "lamination type" shale oil. The tight oil and "lamination type" shale oil are in contiguous distribution.
文摘松辽盆地中央坳陷上白垩统嫩江组是一套分布面积广、厚度大、富含有机质的低熟页岩层系。根据测井资料和岩心实测数据,研究页岩有机质丰度和类型的空间非均质性,据此建立地质模型,并基于生烃动力学和热传导模型,对研究区电加热原位改质资源潜力进行预测。嫩江组各段总体上处于未成熟—低成熟阶段,是以生油为主的烃源岩。嫩江组一、二段古水体为淡水—微咸水,生烃母质主要为藻类体,有机质类型以Ⅱ1—Ⅱ2型干酪根为主,其中嫩一段烃源岩综合品质最好,优质烃源岩主要分布在长岭凹陷新北—大安地区。通过原位电加热模拟可以推断,2 k W加热功率下,页岩温度上升迅速,在加热4年后温度可达到600℃以上;1 kW加热功率下,则需要约8年。有机质转化率在加热到第五年时已经接近100%,达到原位改质最大资源丰度;加热至第五年末,在2 kW功率下,嫩一段页岩可产生的页岩油资源量为245.02×10^8t,嫩二段为65.89×10^8t。
