深海浊积扇朵叶复合体的沉积构成特征与油气水系统:以尼日尔三角洲前缘深水区K油田为例

尼日尔三角洲前缘浊积扇朵叶复合体是西非深水区重要的勘探开发目标，但相关的沉积构成特征与油气水系统研究相对滞后.通过对地震相识别、地震属性刻画、岩心观察及钻井储层进行对比分析，并对研究区的朵叶复合体的沉积构成及储层地质特征进行了研究；依据MDT（mouldar formation dynamics tester）和DST（drill stem testing）测试资料，对朵叶复合体的油气水系统进行了探讨.K油田深海浊积扇朵叶复合砂体在地震剖面上外形呈丘状，内部为弱反射，与泥岩分界面为强振幅反射面，在空间上具有侧向和沿古水流方向迁移的多期叠置特征，平面上呈扇形或"舌状"；测井相以钟形或箱型为主，与周围泥岩呈突变接触；每期朵叶均由朵叶主体和朵叶侧缘构成，重力流水道较为发育.朵叶复合体中的块状砂岩是油田开发的优质储层，该类砂体分布面积相对较大，横向连续性好；目的层段发育多套独立的朵叶复合体油气水系统，每个单一的朵叶复合体油藏上下均受厚度较大的泥岩分隔，具有形成简单完整、统一压力系统、高速渗流能力且水体能量充足的高产油藏的有利条件.K油田朵叶复合体内部结构清晰、砂体侧向连通性好且具有统一油水系统，可作为大陆边缘三角洲前缘深水区富泥背景下深水油气田勘探和开发研究的典型范例. 

The Sedimentary Architecture Characteristics and Fluid System of the Deep Sea Turbidite-Lobe Complex Sandbodies:A Case Study of the Deep-Water Region in the Niger Delta Front

The turbidite lobe complex sandbodies of the Niger Delta front are major oil and gas exploration targets in the deep-water area of the West Africa. But the study of the sedimentary architecture and fluid system is still insufficient. Based on the seismic facies, seismic attributes, core data and drilling reservoir correlation analysis, the characteristics of the sedimentary architecture and geological characteristics of the reservoirs in the study area were comprehensively studied. Besides, the fluid system of the lobe complex sandbodies is also discussed according to the MDT (mouldar formation dynamics tester) and DST (drill stem testing) data. In seismic profiles, the lobe complex sandbodies always with moderate amplitude characteristics and multiple stages can be seen upward. The sandbodies display migration in both lateral and along the paleocurrent direction and present meandering strip on the plane. The log facies of the complex sandbodies mainly correspond to bell shaped-box type, and always with a mutation contact with surrounding mudstone. Each lobe is composed of main lobe and side lobe, and the gravity flow channel is widely developed. The massive sandstone is a high quality reservoir in the oilfield, and the distribution area of the sandbodies is relatively on large scale. The sandbodies developed several sets of fluid system and the lobe reservoir was controlled by mudstone thickness partition, which may have favorable conditions to form a simple and unified pressure system with sufficient water energy. Thus, the sedimentary architecture of the complex sandbodies in the K oilfield is clear, and it has a unified fluid system, which can be used as a typical example of the petroleum exploration in the deep water area and mud-rich setting.