西非尼日尔三角洲盆地A油田深水浊积水道沉积体系沉积特征

doi:10.13745/j.esf.sf.2022.10.10

摘要/Abstract

摘要：

本文运用地震沉积学方法,结合大量岩心和野外露头以及钻测井资料,以高分辨率层序地层学原理为指导,在深水海底扇沉积类型和水道期次划分的基础上,对西非尼日利亚A油田的深水浊积体系进行了深入研究,将深水浊积水道划分为3个界面期次:复合浊积体、复合水道和单一水道,并将Agbada组A油藏中的AU1划分出4期单一水道。详细论述了浊积水道的沉积演化规律,明确了浊积水道受控于古峡谷的限制,以垂向加积为主,生长消亡后,别处重新发育为特征。重力流水道砂体自下而上呈现出由粗变细的正旋回,底部发育大套砂岩夹薄层泥岩,往上泥岩含量增加,测井曲线表现为“钟型”与“箱型”组合,对应地震剖面上强振幅波状反射特征。整体上发生由滑塌-碎屑流到复合水道再演化到水道天然堤复合体的过程。由于受峡谷水道影响,浊积水道体系为限制性和半限制性水道。总结了深水浊积沉积“三元沉积模式”:滑塌、复合水道和水道-天然堤复合体。古河谷规模5 000~7 000 m,内部发育有3期浊积水道体,每一期(单一水道带)由2—4期水道体构成,复合水道带受控于古河谷的控制。整体在峡谷水道呈三元结构,内部多期水道横向迁移,纵向摆动,形成巨厚砂体。底部为碎屑流,泥质-泥屑含量相对高,分选差,渗透率低;中部为水道复合体,为低弯度水道,高砂/地比,渗透率高;顶部为水道-天然堤复合体,属于高弯度水道,低砂/地比,渗透率较低。时移地震证实了水道的期次合理性,水驱油均发生在浊积水道内,依据深水浊积水道期次的精细刻画和时移地震特征,识别出剩余油的分布,成功部署1口采油井,为深水沉积体系的研究提供坚实基础。

关键词: 界面期次, 沉积模式, 时移地震, 深水浊积水道体系, 尼日利亚

Abstract:

The deep-water turbidite system in A oil field, Nigeria, West Africa is extensively studied by seismic sedimentology method, combined with abundant core, outcrop, drilling and well-log data. Based on the obtained high-resolution stratigraphic sequence, deep-water fan types and channel depositional stages, the turbidite channel system is divided into three hierarchical stages—turbidite complex, multichannel complex (AU1-3) and single channel, and AU1 of reservoir A, Agbada group is divided into four single channels. The sedimentary evolution of the turbidity current channels is illustrated in detail. Constrained by ancient valley geography, the channel is mainly formed by vertical accretion, where it narrows upward, with thick sandstone with thin mud interlayers developing at the bottom and mud content increasing upward, as indicated by the bell/block-shaped GR well-log curves, and consistent with a strong-amplitude wavy reflection on the seismic profile. The general succession is lump-debris flow followed by multichannel and channel-levee complexes. Influenced by valley geography, the turbidite channel system mainly consists of restricted and semi-restricted channels. The ancient river valley, 5000-7000 m long, contains 3 stages of turbidite channels, and each stage (i.e., a single channel belt) is composed of 2-4 sub-stages of channel bodies. The multi-stage channels extend laterally and longitudinally to form a giant, thick sand body with a ternary structure: at the bottom is poorly sorted debris flow with relatively high clay content and low permeability; the middle part is low-sinuosity multichannel complex with low sand/land ratio and high permeability; and the top part is high-sinuosity single channels with low sand/land ratio and low permeability. This sedimentary model is supported by the time-lapse seismic data which show that water flooding are within the turbidite channel system. According to the fine staging of deep-water turbidity current channels and related time-lapse seismic features, residual-oil reservoirs are identified and a oil producing well is designed to provide a solid foundation for future research on the deep-water sedimentary system in the oil field.

Key words: hierarchies, sedimentary model, time lapse seismic, deep water tuibidite channel system, Nigeria

中图分类号:

P618.13

陈飞, 范洪军, 范廷恩, 张会来, 赵卫平, 井涌泉. 西非尼日尔三角洲盆地A油田深水浊积水道沉积体系沉积特征[J]. 地学前缘, 2023, 30(4): 209-217.

CHEN Fei, FAN Hongjun, FAN Ting’en, ZHANG Huilai, ZHAO Weiping, JING Yongquan. Sedimentary architecture of the deep-water turbidite system in A oil field, Nigeria Delta, West Africa[J]. Earth Science Frontiers, 2023, 30(4): 209-217.

图/表 9

图1 研究区区域位置及地层单元图

Fig.1 Location, structural map and lithologic unit of the study area

图2 重力流水道沉积特征左—K-2井,水道微相;中—K-6井,块状砂砾岩,高密度浊积水道;右—K-2井,块状中细砂岩,低密度浊积水道。

Fig.2 Gravity sedimentation characteristics in well K-2

表1 重力流水道沉积期次划分及其与河流体系对比

Table 1 Hierarchical architectural divisions of the turbidite channel system and corresponding fluvial systems and relevant sedimentological data

深水浊积水道	典型厚度/m	沉积相	与油组对比	Vail层序地层分级	河流体系
复合浊积体	10~50	古河谷充填体叠置河流沉积体	砂层组	准层序	复合河道带
复合水道	5~20	水道复合体	单砂层/小层	层组	单一河道带
单一水道	3~10	砂质水道/泥质水道组合			复合点坝

图3 深水浊流不连续界线级次划分

Fig.3 Stratigraphic boundary determination in the deep-water turbidite channel system

图4 AU1油藏等时地层格架剖面图

Fig.4 Vertical seismic reflection profile of AU1 isochronous stratigraphic framework

图5 A油田AU1油组沉积相平面分布(左—早期;右—晚期)

Fig.5 Planar distribution of AUI sedimentary facies in the early (left panel) and late (right panel) depositional stages

图6 A油田AU沉积前古地貌特征

Fig.6 Paleogeomorphic characteristics of AU1 before deposition

图7 深水浊流水道沉积模式

Fig.7 Depositional model of the deep-water turbidite channel system

图8 AU1复合体M2时移地震水驱特征(蓝色表征M2水驱范围)

Fig.8 Time-lapse seismic image of AU1 showing 2D water flooding features (in blue)

参考文献 33

[1]	SLATT RM. 陆架至深水泥砂搬运: 沉积物输送体系新解[M]. 周川闽, 张志杰, 陈飞, 等译. 北京: 石油工业出版社, 2019.
[2]	WEIMER P, SLATT R M. 深水油气地质导论[M]. 姚根顺, 吕福亮, 范国章, 等译. 北京: 石油工业出版社, 2012.
[3]	GARRISON L E, KENYON N H, BOUMA A H. Channel systems and lobe construction in the Mississippi Fan[J]. Geo-Marine Letters, 1982, 2(1/2): 31-39. DOI URL
[4]	AMIR A. Channel-levee systems on the Indus deep-sea fan[D]. Cardiff, Wales, UK: Cardiff University, 1993.
[5]	DROZ L, RIGAUT F, COCHONAT P, et al. Morphology and recent evolution of the Zaire turbidite system (Gulf of Guinea)[J]. Geological Society of American Bulletin, 1996, 108(3): 253-269. DOI URL
[6]	PEAKALL J, MCCAFFREY B, KNELLER B. A process model for the evolution, morphology, and architecture of sinuous submarine channels[J]. Journal of Sedimentary Research, 2000, 70(3): 434-448. DOI URL
[7]	陈飞, 胡光义, 孙立春, 等. 鄂尔多斯盆地富县地区上三叠统延长组砂质碎屑流沉积特征及其油气勘探意义[J]. 沉积学报, 2012, 30(6): 1042-1052.
[8]	郑凤云, 史卜庆, 李早红, 等. 尼日尔Termit盆地古近系构造样式及其对油气聚集的控制作用[J]. 地学前缘, 2018, 25(2): 72-82. DOI
[9]	张光亚, 刘小兵, 赵健, 等. 东非被动大陆边缘盆地演化及大气田形成主控因素: 以鲁武马盆地为例[J]. 地学前缘, 2018, 25(2): 24-32. DOI
[10]	李林, 曲永强, 孟庆任, 等. 重力流沉积: 理论研究与野外识别[J]. 沉积学报, 2011, 29(4): 677-688.
[11]	KOLLA V, BOURGES P H, URRUTY J M, et al. Evolution of deep-water Tertiary sinuous channels off shore Angola (west Africa) and implications for reservoir architecture[J]. AAPG Bulletin, 2001, 85(8): 1373-1405.
[12]	朱筱敏, 董艳蕾, 刘成林, 等. 中国含油气盆地沉积研究主要科学问题与发展分析[J]. 地学前缘, 2021, 28(1): 1-11. DOI
[13]	赵鹏飞, 李丹, 杨香华, 等. 尼日尔三角洲前缘重力流水道砂体的沉积构成特征[J]. 地质科技情报, 2014, 33(2): 28-37.
[14]	WYNN R B, KENYON N H, MASSON D G, et al. Characterization and recognition of deep-water channel-lobe transition zones[J]. AAPG Bulletin, 2002, 86(8): 1441-1462.
[15]	NAVARRE J C, CLAUDE D, LIBERELLE E, et al. Deepwater turbidite system analysis, West Africa: sedimentary model and implications for reservoir model construction[J]. The Leading Edge, 2002, 21(11): 1132-1139. DOI URL
[16]	MATTERN F. Ancient sand-rich submarine fans: depositional systems, models, identification, and analysis[J]. Earth-Science Reviews, 2005, 70(3/4): 167-202. DOI URL
[17]	ADEOGBA A A, MCHARGUE T R, GRAHAM S A. Transient fan architecture and depositional controls from near-surface 3-D seismic data, Niger Delta continental slope[J]. AAPG Bulletin, 2005, 89(5): 627-643. DOI URL
[18]	赵晓明, 吴胜和, 刘丽. 尼日尔三角洲盆地Akpo油田新近系深水浊积水道储层构型表征[J]. 石油学报, 2012, 33(6): 1049-1058. DOI
[19]	孙立春, 汪洪强, 何娟, 等. 尼日利亚海上区块近海底深水水道体系地震响应特征与沉积模式[J]. 沉积学报, 2014, 32(6): 1140-1152.
[20]	张佳佳, 吴胜和, 范廷恩, 等. 海底扇水道储层参数建模新思路: 以西非A油田为例[J]. 石油与天然气地质, 2017, 38(2): 407-418.
[21]	KOLLAA V, POSAMENTIERB H W, WOOD L J. Deep-water and fluvial sinuous channels: Characteristics, similarities and dissimilarities, and modes of formation[J]. Marine and Petroleum Geology, 2007, 24(6/7/8/9): 388-405. DOI URL
[22]	蒋恕, 王华, PAUL W. 深水沉积层序特点及构成要素[J]. 地球科学: 中国地质大学学报, 2008, 33(6): 825-833.
[23]	胡光义, 范廷恩, 陈飞, 等. 复合砂体构型理论及其生产应用[J]. 石油与天然气地质, 2018, 39(1): 1-10.
[24]	陈飞, 胡光义, 范廷恩, 等. 渤海海域W油田新近系明化镇组河流相砂体结构特征[J]. 地学前缘, 2015, 22(2): 207-213. DOI
[25]	FIGUEIREDO J J P, HODGSON D M, FLINT S S, et al. Architecture of a channel complex formed and filled during long-term degradation and entrenchment on the upper submarine slope, Unit F, Fort Brown Fm., SW Karoo Basin, South Africa[J]. Marine and Petroleum Geology, 2013, 41: 104-116. DOI URL
[26]	JANOCKO M, NEMEC W, HENRIKSEN S, et al. The diversity of deep-water sinuous channel belts and slope valley-fill complexes[J]. Marine and Petroleum Geology, 2013, 41: 7-34. DOI URL
[27]	MAYALL M, JONES E, CASEY M, Turbidite channel reservoirs e key elements in facies prediction and effective development[J]. Marine and Petroleum Geology, 2006, 23(8): 821-841. DOI URL
[28]	JURAJ J, GIORGIO B. Architecture of coarse-grained gravity flow deposits in a structurally confined submarine canyon (late Eocene Tokaren Conglomerate, Slovakia)[J]. Sedimentary Geology, 2021, 417: 105880. DOI URL
[29]	张会来, 范廷恩, 胡光义, 等. 水驱油藏时移地震叠前匹配反演: 西非深水扇A油田时移地震研究实例[J]. 石油地球物理勘探, 2015, 50(3): 530-535, 564.
[30]	乐靖, 范廷恩, 范洪军, 等. 深海浊积砂岩油藏时移地震定量解释技术研究[J]. 海洋工程装备与技术, 2019(增刊1): 261-267.
[31]	陆红梅, 徐海, 沃玉进, 等. 时移地震“相对差异法”定量预测疏松砂岩油藏含油饱和度: 以西非深海泽塔油田为例[J]. 石油勘探与开发, 2019, 46(2): 409-416. DOI
[32]	BLANCHARD T D, THORE P. Introducing prior information to pressure and saturation inversion: the key for success?[C]// Society of Exploration Geophysicists International Exposition and 83rd Annual Meeting (SEG Houston 2013):Society of Exploration Geophysicists, 2013, 6(6): 4971-4975.
[33]	REDDY K, GUPTA M, MCCLENAGHAN R, et al. Estimation of pore pressure and oil saturation changes in the reservoir using petro-elastic modeling and 4D AVO inversion attributes in the Ravva field[C]// Society of exploration Geophysicists international exposition and 83rd annual meeting (SEG Houston 2013):Society of Exploration Geophysicists, 2013, 6(6): 4981-4985.