基于孔隙度-饱和度参数分析页岩油富集程度

沾化凹陷沙三下亚段为主力烃源岩,也是页岩油勘探评价的主要目标层系,如何筛选页岩油富集和可动层段是目前研究中面临的主要难题。采用氦气法和常压干馏法测定了沾化凹陷罗69井密闭取心的岩石样品,对实验数据的分析表明,沙三下亚段页岩储层含水饱和度随孔隙度增大而减小,当大于某一特定孔隙度界限时,含水饱和度值趋于稳定。提出了页岩储层孔隙度越大、含油饱和度不变或者更高,则可动烃类含量越高的观点,通过对已获油流层段测井响应的分析,提出利用孔隙度、含油饱和度等多参数对页岩油可动性表征的思路,并依据沾化凹陷页岩测井响应特征及参数分布范围对储层富集程度进行了分级评价,其中I类最好,可作为页岩油勘探的主要参考目标。

Enrichment Evaluation of Shale Oil Reservoir Based on Porosity-Oil saturation Analysis:A case study of sha3 formation in Zhanhua Sag

The enrichment evaluation study of shale oil is difficult and has become the focus of unconventional exploration. The lower part of Sha 3 formation is the main hydrocarbon source rocks in Zhanhua sag, which are also the main targhts of shale oil exploration. Water saturation and porosity of shale was determined by the helium method and normal pressure carbonization method. Data analysis shows that the shale oil saturation increases with porosity, and it becomes constant when the porosity beyond a certain limit value. It is presented that the movable hydrocarbon content is increasing with the porosity and oil saturation. The comprehensive geological characteristics of oil shale are analyzed, and evaluation model has been established based on logging data.. On the basis of logging reprocessing of Zhanhua sag, the classification and optimization of favorable target of shale oil reservoir is achieved. This method can provide a reference for the shale oil exploration and comprehensive study in eastern china.