渤南洼陷南坡沙四上亚段沉积特征及控制因素

Sedimentary Characteristics and Controlling Factors of the Upper Submember of Es4 on the Southern Slope of Bonan Sag

摘要: 渤南洼陷是济阳坳陷重要的油气富集区，其中南坡沙四上亚段是油气勘探的重要目的层，多种沉积体系交互发育，沉积特征研究是该区油气勘探的重要基础。利用已钻井岩心、测井、岩石薄片等分析化验资料，对渤南洼陷南坡沙四上亚段开展沉积特征研究，明确沙四上亚段沉积相发育分布规律，并探讨沉积主要控制因素。研究结果表明：沙四上亚段主要发育碎屑岩、碳酸盐岩、膏岩及混积岩等，不同岩石类型混合沉积特征显著；自南部凸起区至洼陷中心依次发育扇三角洲、灰岩滩坝和砂岩滩坝、盐湖泊相等沉积相类型；受控古气候及水体性质、古物源和古地貌等因素共同控制，影响了碎屑物质及碳酸盐岩的供给和生产，并决定了碎屑岩扇体、灰岩滩坝和砂岩滩坝的展布形态。

Abstract: Bonan Sag is an important oil-gas rich area in Jiyang Depression, in which the upper submember of Es4 on the southern slope is an important target layer for oil-gas exploration. The sedimentary characteristics of the upper submember of Es4 in the south slope of Bonan Sag are studied by using the analysis data of drilled core, well logging and thin sections of rock. The development and distribution of sedimentary facies of the upper submember of Es4 are defined and the main controlling factors are discussed. The results show that the upper submember of Es4 mainly develops clastic rock, carbonate rock, paste rock and mixed rock, and the mixed sedimentary characteristics of different rock types are significant. The sedimentary facies types of fan delta, carbonate rock beach bar, sandstone beach bar and salt lake are developed successively from the southern uplift area to the center of depression. The supply and production of clastic material and carbonate rock, and the distribution pattern of clastic fan body, carbonate rock beach bar and sandstone beach bar are influenced by the factors of palaeoclimate, water body, paleoprovenance and palaeogeomorphology.