Weathering volcanic crust reservoir has become an important and new field of oil and gas exploration,its characteristics and distribution rule are of great important theoretical and practical significance to the oil and gas exploration in volcanic rocks.Through comprehensive research of well drilling,cores,logs,seismic and laboratory analyses,weathering volcanic crust reservoir characteristics and distribution rule have been comprehensively studied from the volcanic rock formation environment in Zhongguai uplift,Junggar Basin.The result shows that volcanic rocks formed in the island-arc environment,and lithology is mainly andesite and tuff.The weathering crust structure of volcanic rocks can be divided into four layers:weathered clay layer,strong weathered zone,weak weathered zone and dense non weathered zone.The strongly weathered zone is the best of the four-layer structures,which is the main reservoir development zone.Reserving space mostly contains secondary pores and fractures,and the fracture has a better effect on reservoir seepage capacity.The development of reservoir is affected by lithology and lithofacies,tectonic movement,weathering and leaching,and fault(fracture).Carboniferous system volcanic oil-gas is mainly distributed along the three zones(close to fault zone,structural high part zone,beneficial lithofacies development zone),one side (near the plane of unconformity).%火山岩风化壳储层已成为重要的油气勘探新领域,开展风化壳储层特征及分布规律研究对火山岩油气勘探具有重要的理论和现实指导意义.利用钻井、岩心、测井、地震、分析化验等资料,从火山岩形成环境着手,对准噶尔盆地西北缘中拐凸起石炭系火山岩风化壳储层特征及控制因素开展综合研究,明确火山岩风化壳油气成藏模式及分布规律.研究表明:中拐凸起石炭系火山岩形成于岛弧环境,岩性以安山岩、凝灰岩为主;火山岩风化壳结构分为风化黏土层、强风化带、弱风化带及致密未风化带4层结构,其中强风化带储层物性最好,为主要的储层发育区;有效储集空间主要为次生孔隙和裂缝,裂缝对储层渗流能力有较好的改造作用;风化壳储层主要受风化淋滤作用、岩性岩相、构造位置及断裂(裂缝)等因素的控制;油气主要分布在距风化壳顶面480 m范围内,具有沿三带(靠近断裂带、构造高部位地带、有利岩相发育带)、一面(不整合面附近)分布的富集规律.
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