尼日尔三角洲盆地中新统深水浊流沉积体系演化特征及主控因素  

Evolution characteristics and main controlling factors of deepwater turbidite system in the Miocene of the Niger Delta Basin

作　　者：高云峰 范廷恩 蔡文涛 王夏斌 乐靖 卜范青 陈飞 马良涛 何荣胜 GAO Yunfeng;FAN Tingen;CAI Wentao;WANG Xiabin;LE Jing;BU Fanqing;CHEN Fei;MA Liangtao;HE Rongsheng(CNOOC Research Institute Company Limited,Beijing 100028,China;National Engineering Research Center of Offshore Oil and Gas Exploration,Beijing 100028,China;CNOOC International Limited,Beijing 100028,China)

机构地区：[1]中海油研究总院有限责任公司,北京100028 [2]海洋油气勘探国家工程研究中心,北京100028 [3]中国海洋石油国际有限公司,北京100028

出　　处：《东北石油大学学报》2024年第5期1-16,I0001,共17页Journal of Northeast Petroleum University

基　　金：国家科技重大专项(2017ZX05032-004)。

摘　　要：基于取心、测井和三维地震数据,研究尼日尔三角洲盆地中新统深水浊流沉积地震响应特征、发育演化过程、沉积模式、储层品质及主控因素。结果表明:研究区目的层段自下而上可划分为2个二级层序(Sq1和Sq2)、6个三级层序,主要发育浊积水道、天然堤、溢岸沉积、决口扇及末端扇5种浊积单元;中新世海平面强烈下降阶段的低水位期,从深海盆地逐渐向大陆坡下部过渡,发育浊积水道末端扇体、半限制—非限制性高弯度浊积水道、限制性浊积水道—天然堤复合体沉积,储层为中孔、中高渗物性特征,但砂体规模、砂泥比和横向连续性总体上逐渐变差;中新世,全球冰期气候、强烈构造抬升、海平面不断下降,总体上控制浊流作用的强弱及沉积特征的变化;局部古地貌进一步影响浊流沉积相带分布、规模和形态;目的层段成岩作用弱,沉积条件是影响储层品质的主要因素。该结果为西非深水浊流沉积砂岩油气藏勘探开发提供指导。Based on drilling cores,logging,and 3D seismic data,combined with deepwater turbidity and seismic sedimentology theories,this study investigates the seismic response characteristics,development and evolution processes,depositional models,reservoir quality,and main controlling factors of the Miocene deepwater turbidity deposits in the Niger Delta Basin.The results show that the target layer in the study area can be divided into 2 second-order sequences(Sq1 and Sq2)and 6 third-order sequences.Five turbidite units including turbidite channel,levee,overbank sediment,crevasse splay and terminal fan,can be identified.The turbidite system deposited in the lowstand period of the Miocene when sea level was strongly declining,gradually transitioning from the deep sea basin to the lower part of the continental slope.It successively developed turbidite channel end fans,semi restricted to non restricted high curvature turbidite channels,and restricted turbidite channel-levee complex sediments.All reservoirs are of medium porosity and medium high permeability physical characteristics,but the sand body size,sand and mudstone ratio,and lateral continuity gradually deteriorate overall.In the Miocene,the global ice age climate,strong tectonic uplift,and continuous sea level decline generally controlled the strength of turbidity currents and changes in sedimentary characteristics.Local ancient landforms further affect the distribution,scale,and morphology of turbidite sedimentary facies zones.The diagenesis of the target strata is weak,and sedimentary conditions are the main factor affecting reservoir quality.The research results provide reference for the exploration and development of deep-water turbidite sandstone oil and gas reservoirs in West Africa.

关 键 词：深水浊流沉积 地震沉积 演化特征 储层品质 主控因素 中新统 尼日尔三角洲盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]