随机建模在大牛地气田新区早期气藏描述中的应用

Application of stochastic modeling in early description of gas reservoir in new area of Daniudi Gas Field

鄂尔多斯盆地大牛地气田属于典型的低渗透致密气田,具有储量规模大、发育气层多、储层非均质性强等特点。在早期地质资料较少的情况下,如何客观地预测储层分布及其含气性成为难点。文中的研究对象为大牛地气田新区盒1段河流相致密砂岩储层,以层序地层学、沉积学和地质统计学等多学科的理论和方法为指导,根据现有的钻井、测井、地震、岩心、露头等资料,在基础地质研究的基础上,采用相控随机建模,以相邻开发成熟密井网区精细储层地质模型作为原型模型,通过地质类比分析,确定新区的储层统计特征参数,建立精细可靠的三维储层地质模型,同时结合储层物性下限预测各小层有利储层的分布,为大牛地气田进一步开发提供依据。

Daniudi Gas Field in Ordos Basin belongs to typical low permeability and tight sandstone gas field,which is characterized by a large scale of reserves,multiple gas layers and strong heterogeneity.In the case of lacking the geological data in early time,it becomes a problem how to predict the distribution of gas and reservoir objectively in gas reservoir description.Taking the fluvial low permeability and tight reservoir in new area of the first member of Shihezi Formation in Daniudi Gas Field as an example,following the theories of sequence stratigraphy,sedimentology and geostatistics and starting from principles of fine reservoir modeling,this paper determines the statistical characteristic parameters by the analysis of geological analogy based on the data from drilling,logging,coring,outcrop and geology research.A fine and credible three-dimensional geological model of new area is established by using facies-constrained stochastic modeling.Combined with the minimum limit of physical properties,the distribution of favorable reservoir is predicted,which can provide a basis for the further development of Daniudi Gas Field.