盆缘层序构成模式下的控砂控圈作用研究

哈山地区侏罗系处于盆缘斜坡带构造背景,地层超剥关系复杂,圈闭类型及有效性落实困难,制约了该区的勘探进程。笔者以露头、钻井、地震及分析化验资料为基础,将侏罗系划分为划分为4个三级层序,10个体系域,建立了层序地层格架；层序格架内开展砂体研究表明,区内发育湿地扇相、辫状河相、曲流河相、三角洲相和湖相五类沉积成因砂体,明确了低位域“叠加式”、湖侵域“孤立式”、高位域“切叠式”三类砂体叠置样式,建立了2类4种体系域控圈模式；不整合结构特征、体系域控砂模式耦合控制了不同层序内的圈闭类型及发育规律,低位域毯砂主要发育构造地层圈闭,湖侵域、高位域发育地层-岩性圈闭。

Research on the Role of the Basin-marginal Sequence Architectural Model in Controlling the Development of Sand-bodies and Traps-a Case Study of the Jurassic System in Hashan Area

The Jurassic system in Hashan area is under the tectonic setting of basin-marginal slope, and the complex contact relationship of strata and difficulties in determining the type and effectiveness of traps restricted prospecting courses of this area. According to the outcrop, drilling, seismic and analysis data, the Jurassic system can be divided into 4 third order sequences and 10 system tracts, and sequence stratigraphy framework is established. Through research on sand bodies within the sequence framework we find that Hashan area mainly developed sandbody of humid fans, braided fluvial, meandering fluvial, delta and lacustrine facies, make clear that three types of sandbody stacking patterns are overlap type in LST, isolation type in TST and dissecting-stacking type in HST, and established system tract controlling trap models of 4 classes in 2 types. The unconformity structural characteristics and system tract controlling sand body model coupling controlled the types and development rules of traps in different sequences, that is, carpet sand bodies in LST mainly developed structural-stratigraphic traps, while sandbody in TST and HST developed stratigraphic- lithologic traps.