| 作 者：刘邦，潘校华，万仑坤，毛凤军，刘计国，程顶胜 |
| 单 位：中国石油勘探开发研究院 |
| 基金项目：本文受“海外重点裂谷盆地油气成藏规律及目标优选”（编号：2008ZX05029-001）资助 |
| 摘 要： |
| 东尼日尔盆地是中西非裂谷系中典型的中要新生代裂谷盆地。Tenere坳陷位于盆地西北部,包括西部凹陷、东Ⅰ凹陷和东Ⅱ凹陷。对Saha-1井上白垩统岩屑样品的分析揭示,干酪根显微组分以不发荧光或弱荧光的无定形体 为主,岩石抽提物中C29甾烷优势明显,说明该井上白垩统泥岩有机质输入以陆源植物为主。岩石热解分析表明上白垩 统Yogou组泥岩大多数为中等—好烃源岩,有机质以Ⅱ2-Ⅲ型为主,Donga组泥岩大部分为差—中等烃源岩,以Ⅲ型为 主；岩石热解峰温指示烃源岩成熟门限深度为2300 m左右。生烃史模拟显示,Saha-1井Yogou组泥岩尚未开始生烃, Donga组在白垩纪末期开始生烃,下部已进入生气阶段。综合研究认为Tenere坳陷的西部凹陷勘探潜力较大,而东Ⅰ凹 陷和东Ⅱ凹陷潜力有限。 |
| 关键词：东尼日尔盆地；Tenere 坳陷；上白垩统；海相地层；烃源岩评价；勘探潜力 |
| Author's Name: Liu Bang, Pan Xiaohua, Wan Lunkun, Mao Fengjun, Liu Jiguo, Cheng Dingsheng |
| Institution: PetroChina Research Institute of Petroleum Exploration and Development |
| Abstract: |
| Eastern Niger Basin is a typical Mesozoic-Cenozoic intracontinental rift basin of the Central-Western African rift system. The Tenere Depression, located in the northwestern part of the basin, includes the Western Sag, EasternⅠSag and Eastern Ⅱ Sag. Analysis of mudstone cuttings from Well Saha-1 has revealed that kerogen macerals are dominated by amorphinite without or with weak fluorescence and C29 regular sterane are predominant in rock extracts. On these characteristics, it is suggested that the organic matter of the Upper Cretaceous mudstones mainly derived from terrigenous plants. Rock-Eval pyrolysis data reveals that the Upper Cretaceous Yogou mudstone generally is moderate to good hydrocarbon source rock with predominant Type Ⅱ2 to Type Ⅲ of kerogen while the Donga mudstone is mainly poor to moderate source rocks with Type Ⅲ of kerogen. The Tmax values indicate that the depth of hydrocarbon-generating threshold is about 2300m. Thermal-burial history modeling implies that of Yogou mud-stone (Well Saha-1) is not mature. Donga mudstone has reached the oil-generating threshold at the end of Cretaceous and the lower part of Donga is in gas-generating stage. By integrated study, it is suggested that better potential for hydrocarbon exploration exists in Western Sag compared with that in the Eastern Ⅰ Sag and Eastern Ⅱ Sag. |
| Keywords: Upper Cretaceous; Marine strata; Source rock Evaluation; Exploration potential; Tenere Depression; Eastern Niger Basin |
| 投稿时间： 2011-07-11 |
