基于井震的火山岩有利储层综合预测——以银额盆地哈日凹陷为例

Integrated Prediction of Overflow Facies Andesite Reservoir Based on Well and Seismic Data:a Case from Hari Sag in Yin’e Basin

银额盆地哈日凹陷延哈5井安山岩试出低产油气流,指示了火山岩是该区的重要储层类型之一。为明确哈日凹陷下白垩统火山岩的分布规律、储层特征及勘探潜力,应用岩心、测井及地震资料综合研究了安山岩的地质地球物理特征和有效储层分布。结果表明:哈日凹陷巴一段火山岩层具有上、下两段结构,下段发育安山岩,上段发育凝灰岩、火山碎屑岩与过渡岩性。下段安山岩具气孔和溶蚀孔隙,发育交织结构及杏仁构造,呈厚层块状,自然伽马曲线呈箱型(70~80 API),具有顶底强振幅、内部弱振幅和高波阻抗地震响应。火山口及安山岩加厚带主要沿缓坡带轴向断裂呈串珠状分布,剖面上呈低丘状或透镜状。与孔隙度反演、裂缝识别和含油气性检测等手段综合预测的安山岩有利含油气区相互吻合。

Low yield oil and gas flow was output from the andesite of well Yh5 in Hari sag,Yine Basin,indicating that volcanic rock is one of the important reservoir types in this area.In order to characterize the andesite reservoir and evaluate the exploration potential of volcanic rocks in Hari sag,an integrated geologic and geophysical research was conducted using core,logging and 3D seismic data.The results show that the volcanic rocks developed in the lower section of Bayingebi Formation in Hari Sag consist of two sections.The lower section is overflow facies andesite,and the upper section is explosive facies and volcanic sedimentary facies.The andesite is thick and massive,with interwoven texture and almond structure,and gas pores and dissolved pores.The andesite shows box-shaped natural gamma curve of 70~80 API,forming strong seismic amplitude reflections at its top and bottom interfaces and weak amplitude in it.Crater and andesite thickened zone are mainly distributed as a bead string along strike faults of the sag gentle slope.The favorable andesite reservoirs predicted by means of post stack porosity inversion,fracture identification and oil-gas detection distribute in the approximately same area.