苏东南地区盒8段砂体叠置关系及其对气水分布的影响

Sandbody Superimposition Relation of 8th Member of Shihezi Formation in Southeastern Sulige and Its Influence on Gas-water Distribution

苏东南地区盒8段砂体叠置类型及气水分布关系复杂,研究砂体的垂向叠置关系及横向叠置类型对于查明研究区盒8段的气水分布影响因素有重要意义。依据野外露头及岩心观察、薄片鉴定、测井解释等方法对研究区盒8段沉积微相类型、砂体的垂向及横向叠置关系以及对气水分布的影响进行研究。结果表明,研究区盒8段属于辫状河三角洲平原亚相,并可划分为分流河道与泛滥平原沉积微相。砂体垂向叠置关系主要包括块状砂体、多层叠置砂体、分段互层砂体及薄互层砂体,横向叠置类型主要包括孤立砂体、垂向叠置、水平搭接及切割叠置4类。盒8下亚段砂体垂向叠置关系以多层叠置砂体与分段互层砂体组合为主,其数量高于盒8上亚段。气层及含气层多富集于盒8下亚段的垂向叠置及切割叠置类砂体中,气水同层及水层主要分布于盒8上亚段的孤立砂体底部或水平搭接砂体的边部。

The types of sedimentary microfacies,the vertical and horizontal superimposition relationships of sandbodies,and their influences on the gas-water distribution in the 8 th member of Shihezi Formation of southeastern Sulige were studied based on outcrop and core observation,thin section identification and logging interpretation. The results show that the 8 th member of Shihezi Formation of the study area belongs to the braided river delta plain subfacies,and it can be divided into distributary channel and flood plain sedimentary microfacies. The vertical superimposition relationship of sandbodies mainly includes massive sandbodies,multi-layered sandbodies,sectional interbedded sandbodies and thin interbedded sandbodies,while the horizontal superimposition types mainly include isolated sandbody,vertical superimposition sandbodies,lateral overlap sandbodies and dissected superimposition sandbodies. Vertically the lower part of 8 th member of the Shihezi Formation is mainly composed of multi-layered sandbodies and sectional interbedded sandbodies,and their number is greater than in the upper part of 8 th member of the Shihezi Formation. The gas layer and the gas-bearing layer are mostly concentrated in the vertical superimposition sandbodies and the dissected superimposition sandbodies of the lower part of 8 th member of the Shihezi Formation,while gas-water layer and water layer mainly distribute at the bottom of the isolated sandbody and the edge of the lateral overlap sandbody of the upper part of 8 th member of the Shihezi Formation.