车排子东缘沙湾组薄互层油藏分布特征

Thin Interlayer Reservoir Distribute Character of Shawan Formation in Eastern Chepaizi Area

车排子地区沙湾组含油气地层主要以沙一段夹杂于灰质砂岩中的疏松砂岩条带为主,结合沉积相分析认为,受到多期物源以及沉积变化的影响,该油藏具有厚度薄、横向变化快的特点。受地震分辨率限制,采用反演、属性分析等方法无法对该薄互层油藏中有效储层厚度变化进行准确刻画。针对这种薄夹层储层,结合测井、岩心资料建立地质模型进行地震正演,分析发现在围岩厚度一定的情况下地震响应特征与有效储层厚度之间存在单调变化关系,根据这个特征,建立不同围岩厚度条件下的储层厚度-属性模板,综合利用地震属性、地震反演结果实现对研究区有效储层厚度变化的预测。结合区域研究成果与储层预测,车排子东缘沙一段主要可划为两套不同类型沉积,有效储层的分布特征主要受两种沉积的分布影响。

The oil strata in the Shawan Formation of Chepaizi area are mainly composed of the unconsolidated sandstone strata in the calcareous cementation sandstone.Sedimentary analysis found that,the reservoirs have the characters of small thickness and fast change in horizontal influenced by different sources and the change of sedimentary.Limited by the resolution of seismic data,the seismic techniques such as attribute and inversion analysis can not describe the transverse change of effective reservoirs.Focusing on the thin reservoirs,the seismic model of this kind reservoir was built combined with the well logs and core data and the relation between seismic reflection and the reservoir thickness was found.According to this character,a thickness-seismic attributes template in different surround rock thickness could be built for the comprehensive use of seismic attribute and inversion and the prediction of the thickness change of effective reservoir in the research area.Combined with the region research and reservoir prediction,the Shawan 1 group can be divided into two kinds of sedimentary which are the primary reasons that influence,the characters of reservoir distributes.