准噶尔盆地西北缘二叠系扇三角洲层序特征及砾岩油藏分布规律

岩性地层油气藏是我国陆上油气勘探的重点领域之一,本文针对我国西部前陆盆地勘探程度相对较低的中深层陆相砾岩油藏,选取准噶尔盆地西北缘八区中-下二叠统作为研究对象,综合岩心观察、测井和三维地震资料的精细解释,在开展层序地层学和沉积相研究的基础上重点解剖典型的扇三角洲砾岩油藏,分析层序地层格架内砾岩油藏的分布特征,揭示出研究区具有一扇多藏的油藏分布规律。勘探开发实践表明,研究区砾岩油藏主要发育于水进体系域扇三角洲前缘水下分流河道储集体中,其次为高水位体系域中,以物性遮挡岩性油藏、物性封闭岩性油藏以及断裂-岩性复合油藏为特征。

Sequences and conglomerate reserves distribution of the Permian fan-delta in the northwest margin of Junggar Basin

Lithostratigraphic reserves have potential hydrocarbon resources in the continent of China.However,terrigenous conglomerate reserves in middle to deep depth underwent relatively low exploration in foreland basin in west China.In this paper,we choose Middle-Lower Permian of the 8th area in northwestern Junggar Basin to analyze the characteristics of the sequences and conglomerate reserves distribution of the Permian fan-delta.Integrated with the information of the cores,well-line logs and 3D seismic data in the study area,we analyze the typical fan-delta conglomerate reserves using the methods of sequence stratigraphy and sedimentology and reveal its distribution in the sequence stratigraphic framework.Exploration and development practice showed that the conglomerate reserves are mainly developed in underwater distributary channel reservoirs of the fan-delta front in transgressive systems tracts,followed by high-stand systems tracts,and principle reserves are permeability barrier lithologic reserves,physical sealing lithologic reserves and fault-lithologic reserves.