吉木萨尔凹陷致密油有利区预测及潜力分析

Favorable Area and Potential Analyses of Tight Oil in Jimsar Sag

吉木萨尔凹陷二叠系芦草沟组发育一套云质岩储集层，是致密油勘探的重点区域和层位。该区域致密油以源储一体及源储互层为特征，形成了良好的源储配置关系。根据钻井、测井、地震及样品实测数据，结合前人研究成果，在详细剖析吉木萨尔凹陷二叠系芦草沟组致密油石油地质特征的基础上，考虑致密油储层的孔隙度、储层厚度以及烃源岩有机碳含量、成熟度等因素，确定了致密油资源评价参数分类标准，将芦草沟组上、下“甜点体”各划分出Ⅰ、Ⅱ、Ⅲ类有利区。使用小面元容积法对吉木萨尔凹陷致密油有利区进行资源预测，芦草沟组上、下“甜点体”石油地质资源量分别为4．72×10^8、7．49×10^8t。研究表明，吉木萨尔凹陷二叠系芦草沟组致密油具有较大的勘探潜力。

There is a set of dolomitic reservoir in the Permian Lucaogou Formation of Jimsar Sag and this dolomitic reservoir is considered as a key area and formation for tight oil exploration. Tight oil in this area is characterized by in-source accumulation and source-reservoir interbedding,which show favorable source-reservoir configurations. According to the drilling,well logging,seismic,core test and other data,the tight oil geology in Permian Lucaogou Formation of Jimsar Sag is comprehensively analyzed by combining the previous researches. The parameter classification criteria for tight oil resource assessment is established by considering tight oil reservoir porosity,reservoir thickness,source-rock organic carbon content,maturity,etc. The'sweet-spots'in the upper and lower Lucaogou Formation are classified as Type-Ⅰ,Type-Ⅱ and Type-Ⅲ favorable areas. Volumetric method of small surface element is used to estimate the tight oil resources of favorable areas in Jimsar Sag. The geological petroleum resources of'sweet-spots'in the upper and lower Lucaogou Formation are 4. 72× 10~8 t and 7. 49 × 10~8 t respectively. Research shows relatively great exploration potential for the tight oil resource in Lucaogou Formation of Jimsar Sag.