珠江口盆地白云凹陷B区块重力流水道-朵叶体系构型研究

    Sedimentary architecture of gravity flow channel-lobe system of Block B in Baiyun Sag

    • 摘要: 珠江口盆地白云凹陷中新统重力流沉积极为发育,是重要的油气产层之一。前人对大型重力流沉积形成机理研究较多,但对其微相的精细刻画及构型的分析研究较为薄弱。本文通过岩芯、测井、地震及生产动态等资料,开展了白云凹陷B区块中新统珠江组ZJ460小层7级重力流水道-朵叶体系构型及连通性研究。研究结果表明:①研究区重力流水道朵叶体系极为发育,水道、堤岸和朵叶较为常见。②水道构型样式包括深切型、切叠型及孤立型。切叠型样式极为发育,可进一步分为垂向、侧向及斜列切叠型;朵叶以补偿叠置最为常见;从北向南,水道构型样式由深切型、切叠型向孤立型变化。③研究区发育约10条大型水道-朵叶体系。北部及中部水道-堤岸体系发育,向南逐渐过渡为朵叶;水道-堤岸体系大致相互平行,南部多个朵叶相互叠置,形成朵叶发育带。④研究区北部水道-堤岸体系相互连通,南部朵叶带相互连通,水道与水道末端朵叶连通性好;水道-堤岸体系连通性受控于水道之间的距离、规模及大型水道-堤岸体系之间小型水道-朵叶体系的发育数量。本研究成果可直接指导研究区挖潜,还可为类似气田提供借鉴。

       

      Abstract: Gravity flow deposits were well developed during the Miocene in Baiyun Sag, the Peral Mouth Basin, and they important oil and gas producing layers. Most previous works focused on mechanism of large-scale gravity flow deposits, while detailed work and architecture study are weak. Using core, drill, seismic, property and production performance, and so on, we anatomized the sedimentary architecture and connectivity of gravity flow channel-lobe system in 7 tiers for the Miocene ZJ460 layer in B Block of Baiyun Sag. Results show that the gravity flow channel-lobe systems were common in the study area, consisting of channel, levee, and lobe. The channel architecture can be divided into deep cut, cut-and-fill, and isolate types. The cut-and-fill type contain vertical agrradational, lateral agrradational, and diagonal agrradational stackings. Compensation agrradational style is usually developed in lobe, channel agrradational styles change from cut, cut-and-fill, to isolate styles from north to south and similarly from bottom to top in the study area. There were about 10 large channel-lobe systems. Channel-levee systems were developed in the north, and they gradually evolved southward into lobe. Chaneel-levee systems were parallel to each other. Several lobes overlay each other in the south, and formed into lobe zone. The channel-levee systems are connective in the north of study area. Lobes are also connective in the south. Channel and channel terminal lobe are well connective. The distance, scale of channel, and number of small channel-lobe systems between two adjacent large channel-levee systems controlled the connectivity quality. This work not only could directly help exploration of potential, but also provide guidance for the similar gas fields.

       

    /

    返回文章
    返回