川西坳陷须家河组三段沉积特征及勘探潜力

川西坳陷上三叠统须家河组三段的油气勘探一直未能取得突破,前人研究认为该层段主要为湖沼相沉积,缺乏良好的储集条件。为进一步搞清楚该层段的储层特征及勘探潜力,借助层序地层学分析方法,通过地震相和沉积相划分,将须三段分为上、下2个旋回,预测出其有利的沉积相带。从储层发育情况、油气运移通道以及油气藏保存条件等几个方面着手,对该层段的油气勘探潜力进行了综合分析。结论指出:须三段下部旋回在川西坳陷东部斜坡带具有较好的勘探潜力,而上部旋回在西部斜坡带也具有一定的勘探潜力。

Sedimentary features and exploration potentials of the third member of the Xujiahe Formation in West Sichuan Depression

No breakthrough has been made in the exploration of the third member of the Upper Triassic Xujiahe Formation in West Sichuan Depression. Previous studies believe that this interval is mainly of limnetic facies without good poroperm characteristics. In order to understand the features and exploration potentials of the reservoirs in this interval, sequence stratigraphic methods, in combination with the division of seismic facies and sedimentary facies, are used to divide this interval into two sedimentary cycles (an upper and a lower cycle) and to predict the favorable sedimentary facies belts. The exploration potential of this interval is comprehensively analyzed in respect of reservoir development, hydrocarbon migration pathways and hydrocarbon preservation. It is pointed out that the lower cycle has relatively high exploration potential in the eastern slope zone, while the upper cycle has some exploration potential in the western slope zone.