准噶尔盆地西北缘南白碱滩断裂成岩封闭作用研究

摘要

从封闭机理上看,影响断层封闭性的主要因素包括：涂抹作用、碎裂作用及成岩作用。其中成岩作用是静止期断层逐渐封闭的主导因素,其类型主要包括：压实和充填作用、胶结作用,二者对断层的封闭性均具有建设性作用。根据地震、测井、录井及试油等资料,运用定量计算的方法,并结合岩心和岩石薄片观察,对准噶尔盆地西北缘南白碱滩断裂内成岩作用进行了研究。结果表明：由于南白碱滩断裂内压实和充填作用强烈,加之受胶结作用的影响,使断裂带与相邻围岩相比具有较低的孔隙度和渗透率,致使该断裂的封闭性较好,对油气具有良好的封堵作用。最后通过断裂带结构划分,初步认为南白碱滩断裂内成岩胶结作用的影响范围为50～80m。%From the point of sealing mechanism,the factors that affect the closure property of fault are smear effect,fragmentation and diagenesis.Diagenesis is the dominant factor for the gradually closed effect of quiescent fault.Diagenesis types that affect the closure property of faults are compaction and packing action,as well as cementation,which are all constructive for the closure property of faults.Based on the seismic,well logging and testing data,combined with core and rock slice observation,the quantitative calculation method is applied to carry out the study on the diagenesis of Nanbaijiantan fault in northwestern margin of Junggar Basin.The result shows that because of the strong compaction and packing action,as well as cementation,the faulted zone in Nanbaijiantan has lower porosity and permeability,and the fault has good closure property.Through structure division of faulted zone,combined with core and rock slice observation,it is considered that the influence area of diagenetic sealing in the study area ranges from 50 to 80 meters.