奈及利亞構造特徵與油氣儲聚

Structural Styles and Hydrocarbon Accumulation in Nigeria

王佳彬(J.B. Wang) ； 楊耿明(K.M. Yang) ； 吳榮章(J.C. Wang)

《鑛冶：中國鑛冶工程學會會刊》 50卷4期 (2006/12) Pp. 80-96

https://doi.org/10.30069/MM.200612_50(4).0006

摘要

尼日三角洲基底逆衝系統主要由位於含有高孔隙流體壓力（λ≒0.9）Akata地層上非常脆弱之底層的滑脫作用所造成，為相當薄的低角楔體（low-angle taper），該滑脫面明顯影響深海褶皺帶的構造型態。尼日三角洲的封閉型態主要有四種，分別為：含頁岩充填河谷的反傾構造、多重生長斷層構造、反傾斷層構造及崩塌構造，而以與斷層有關之背斜構造之油氣產量最大。該三角洲北方主要封閉構造為反傾背斜，局部油田是斷層封閉及由岩層尖滅與河道切割造成的地層封閉。構造－地層封閉多發現於東南方，尤其是深海遠濱區。尼日三角洲的油田多位於大構造上與三角洲之凹陷上，為未來探勘之重點。天然氣在尼日三角洲日趨重要，可能成為最重要的能源來源。

關鍵字

尼日三角洲 ； 構造封閉 ； 低角間體 ； 地層封閉

並列摘要

The sole thrust system in the Niger delta has been caused by detachment alone the fragile base of the Akata formation , which is characterized by high pore pressure (λ≒0.9). The thrust system forms as a thin low-angle taper wedge and the basal detachment dominates the formation of structural styles of fold belt in the deep-water areas. There are four types of trap in the Niger delta: roll-over structures of infilled-valley strata containing shale, multiple growth fault structures, antithetic fault structures and collapsed structures. Among the trap types the fault-related fold anticlinal structures are the most productive traps. The major structural traps in the northern part of the delta are the roll-over anticline and some of oil fields can be categorized as fault traps and stratigraphy traps formed by pinched-out strata and channel truncation. Most of the structural-stratigraphy traps are discovered in the southeastern part of the delta, especially in the deep-water areas. The oil fields in the Niger delta are mostly located in the tectonic settings of large scale and the sag areas of the delta; therefore, such areas should be the targets for the future exploration. In the final, natural gas produced in the Niger delta will be more important and become the crucial source of energy in the future.

並列關鍵字

Niger delta ； Structural traps ； Low-angle taper wedge ； Stratigraphy trap