浅水三角洲分流河道砂体内部结构及其对气水分布的影响——以四川盆地中江气田沙溪庙组为例

研究四川盆地中江气田中侏罗统沙溪庙组河道砂体内部结构特征及其对气水分布的影响.在现代沉积、野外露头、岩心、测井、地震资料和生产测试资料的基础上,开展了浅水三角洲分流河道砂体内部结构特征研究,建立了相应的构型模式,分析了不同河道构型模式下的气水分布特征.结果表明:沙溪庙组为曲流河入湖的河控浅水三角洲平原—前缘沉积,发育曲...

Internal structure of distributary channel sand body and its effect on gas-water distribution in shallow-water delta:A case study of Shaximiao Formation in Zhongjiang Gas Field,Sichuan Basin,China

On the basis of modern sedimentary data,outfield data,drilling core data,logging data,seismic data and production test data,the internal structure characteristics of shallow-water delta distributary channel sand bodies in middle Jurassic Shaximiao Formation in Zhongjiang Gas Field,Sichuan Basin are studied,and its corresponding configuration model is established.Then,the distribution characteristics of gas and water under different channel configuration models are analyzed in order to explore the internal structure characteristics of channel sand body and its influence on gas and water distribution in the area.The material of Shaximiao Formation is shallow-water delta plain front deposition,formed in the channel where meandering river enters the lake and where meandering distributary channels,low sinuosity distributary channels and straight underwater distributary channels developed.Meandering distributary channels and low sinuosity distributary channels are dominated by side deposits,with point bars and abandoned channels developed.The straight channel is dominated by vertical accretion with foreset body and foreset bed.The lateral deposits and abandoned channels form circular lithologic(or physical property)blockages,leading to good gas content in some lateral deposits in meandering distributary channels.The gas and water in low sinuosity distributary channels are“sausage type”distribution,and gas layer development can also be seen in low structural parts.Horizontal interbeds are mainly developed in straight distributary channels,and the heterogeneity along the channels is weak.In the channel,the distribution characteristics of upper gas and lower water are shown,and the high parts of the structure are mainly composed of gas layer,while the low parts and near fault layer are mainly composed of gas&water and water layers.