双南构造SQ3水进域湖底扇砂体识别及含油气性分析

Identification and petroliferous analysis of the sublacustrine fan sand bodies in SQ3 transgressive system tract of Shuangnan Structure

双南构造SQ3水进期湖相泥岩沉积中发育一套砂质储层,含油丰度较高,但井间产能差异较大,岩心见不完整的鲍玛序列,综合测井相、地震相分析确定为湖底扇沉积砂体。在五级层序格架控制下,结合湖底扇地震反射特征选取敏感振幅属性及零交叉点属性定性刻画砂体的分布边界;运用测井约束储层反演技术,定量刻画砂体的分布范围。结果表明,湖底扇砂体分为两期,其中湖底扇供给水道及中扇辫状沟道砂体次生孔隙发育且连通性好,为中孔中渗储层,含油气丰度及单井产能均优于其他相带,为本区的优势储层。结合双南构造的区域构造特点,将其划分3类有利目标区。

A set of sandy reservoirs with high oil abundance developed in the SQ3 water-bearing lacustrine mudstone deposition of Shuangnan structure.However,the productivity difference between wells is large,incomplete Bauma sequence can be seen in the core,through comprehensive logging facies and seismic facies analysis,it is determined to be the lacustrine fan sedimentary sand body.Under the control of five-level sequence lattice,the sensitive amplitude attribute and zero crossing point attribute are selected and the distribution boundary of sand body is characterized qualitatively by combining the seismic reflection characteristics of sublacustrine fan.The distribution range of sand body is quantitatively characterized by well logging constrained reservoir inversion technique.The results show that the sand bodies in sublacustrine fan are divided into two stages,in which the supply channel of the sublacustrine fan and the braided channel of the middle fan are well developed and well connected,and they are medium-porosity and mediumpermeability reservoirs,and they are the dominant reservoir in the area.The hydrocarbon abundance and the productivity in the single well are better than that of in other facies belts.According to the regional structural characteristics of Shuangnan structure,it can be divided into three kinds of favorable target areas.