银额盆地哈日凹陷安山岩储层综合识别

Integrated Identification of Andesite Reservoir in Hari Sag,Yine Basin

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,通过岩心、测井及地震储层综合预测方法研究了安山岩的地质地球物理特征和有效储层的分布。结果表明:安山岩具气孔和溶蚀孔隙,显微镜下见交织结构及杏仁构造,测井地层对比图上呈厚层块状和箱型自然伽马曲线形态,自然伽马值介于70~80 API。地震剖面上安山岩层具有顶底界面强振幅内部弱振幅特征。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,火山口地震剖面上呈低丘状或透镜状。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。可见该研究成果对该区及具有类似地质背景的火山岩油气勘探提供了一定的思路和方法,具有重要的借鉴意义。

In order to characterize the andesite reservoir and evaluate 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 dissolved andesites are mainly composed of interwoven feldspar and almonds under microscope and cores,and possess 70~80 API box shape of the natural gamma curves on logging correlation cross-sections.The top and bottom andesite correspond two strong amplitude reflections with interior weak amplitudes.Volcanic craters arranged in beads along an axial fault on the gentle slope of the sag,where the andesites are thicken as hummocky or lenticular reflections on 3D seismic sections.The favorable oil and gas plays of andesite are characterized based on seismic porosity inversion,fracture identification and gas detection.The three seismic methods have predicted consistent favorable areas.This research provide valuable methods for depict andesite reservoirs in this area and have important significance to other similar regions.