歧口凹陷港西地区浅层气的AVO检测方法

AVO Detecting Method of Shallow Gas in Gangxi Block,Qikou Depression

首次利用三维高分辨率地震AVO技术分析了港西油田浅层新近系明化镇组的含气响应特征,先通过AVO正演模拟研究了含气储层的AVO异常响应特征,并以此为依据指导对基于叠前地震资料反演AVO异常属性的解释。然后基于叠前地震资料进行AVO反演,提取AVO异常属性参数,基于各种属性特征来预测储层的分布和含气性状况,并通过相关性对属性进行优化,分析了其多解性。该方法可以指导对港西大范围含气性进行可靠的预测,对提高港西浅层气藏的勘探与开发具有较大的实际意义。

Gangxi oilfield is rich in shallow gas resources in Neogene,and its g as reservoirs are characterized by shallow buried depth,complex origins,small reserves,many types and wide distribution.In this paper,the three-dimensional high-resolution seismic AVO technology was used for the first time to analyse t he gas response characteristics in Minghuazhen Formation of Gangxi shallow layer s.At first,based on the pre-stack seismic data,the gas-bearing reservoir is s tudied in response to the abnormal characteristics of the AVO through the AVO fo rward model,and used as the basis for inversion AVO anomalies to explain the pr operties.Then,based on pre-stack seismic data,AVO inversion is proceeded,and AVO abnormal attribute parameters are extracted.Finally,based on attributes c haracteristics,prediction is made for the distribution of reservoir and gas-bea ring status,and the attributes are optimized by correlation calculation to anal yze the ambiguity.Thereby,this can offer guidance for a reliable gas forecasti ng in Gangxi block.It has great practical significance for improving the explor ation and development of shallow gas pool in Gangxi block.