北部湾盆地迈陈凹陷涠洲组扇体发育特征与成藏  

Reservoir formation and development characteristics of fan in the Weizhou Formation fan of Maichen Depression in the Beibu Gulf Basin

作　　者：刘宏宇[1] 陈伟[1] 王花 方涛[1] 施琰[1] 刘喜欢[1] LIU Hongyu;CHEN Wei;WANG Hua;FANG Tao;SHI Yan;LIU Xihuan(Exploration and Development Research Institute of Jiangsu Oilfield Company,SINOPEC,Yangzhou 225009,China)

机构地区：[1]中国石化江苏油田分公司勘探开发研究院,江苏扬州225009

出　　处：《复杂油气藏》2023年第4期374-379,共6页Complex Hydrocarbon Reservoirs

基　　金：江苏油田重点科技攻关项目“迈陈凹陷成藏深化研究及勘探方向”(JS22002)。

摘　　要：北部湾盆地迈陈凹陷是典型的南断北超的箕状断陷,发育“南扇北洲”沉积体系。南部断裂带—深凹带钻井揭示扇根水道、扇中水道等沉积微相,研究认为涠洲组发育多期叠置的大型扇体,可划分为5套扇体组合,细分为18期扇体。受构造、沉积演化的控制,迈陈凹陷发育的扇体可形成扇根遮挡型、上倾尖灭型、断层-岩性型3种类型圈闭。南部扇体具有良好的成藏配套条件,深凹带烃源岩厚度大、成熟度高,长期处于增熟排烃过程;多套泥岩盖层与扇中砂岩形成良好储盖组合;涠二段至涠三段中上部发育优质扇中砂岩储层;深凹带排烃早、油气充注时间更长,有利于形成富集规模油藏。因此,迈陈凹陷断裂带—深凹带扇体隐蔽圈闭是获得规模储量的重要勘探领域。The Maichen Depression in the Beibu Gulf Basin is a typical dustpan-shaped fault depression that was faulted in the south part and overlapped in the north with the development of the“southern fan and northern delta”sedimentary system.Drilling in the southern fault zone and the deep depression zone reveals the sedimentary microfacies such as fan-root and fan-middle channels.It is believed that the Weizhou Formation has developed a large fan body with multiple overlapping stages,which can be divided into five sets of fan body combinations and subdivided into 18 stages of fan bodies.Under structural and sedimentary evolution control,the fans developed in the Maichen Depression can form three traps:fan-root blocking,updip pinch-out,and fault-lithology.The southern fans have good conditions for reservoir formation,and the source rocks in the deep depression zone have large thicknesses and maturity and have been maturing and hydrocarbon expulsion for a long time.Multiple sets of mudstone caprocks and sandstone in the fan form a good combination of reservoir and cap.High-quality fan sandstone reservoirs have been developed in Section 2 of the Weizhou Formation and the middle and upper parts of Section 3.The deep concave zones have an early expulsion of hydrocarbon,and the oil and gas filling time is much longer,which is favorable for forming a rich-scale reservoir.Therefore,the subtle traps of the fans in the fault zone and the deep depression zone of the Maichen Depression are important exploration areas for obtaining large-scale reserves.

关 键 词：沉积体系 扇体期次 扇体圈闭 成藏模式 迈陈凹陷 

分 类 号：TE132[石油与天然气工程—油气勘探]