莺-琼盆地轴向水道沉积演化及勘探前景

Sedimentary Evolution and Exploration Prospects of Axial Channel in Ying-Qiong Basin

何小胡 张迎朝 张道军 陈杨 黄灿

HE Xiaohu ZHANG Yingchao ZHANG Daojun CHEN Yang HUANG Can

中国海洋石油总公司南海西部石油管理局, 广东 湛江 524057

CNOOC Nanhai West Petroleum Bureau, Zhanjiang, Guangdong 524057, China

莺琼盆地在莺歌海期和黄流期发育大规模的轴向水道沉积体系，但由于对这种轴向水道的成因机制及水道砂体的分布规律缺乏系统认识，勘探一直未能取得商业性突破。针对制约轴向水道沉积体系勘探的物源和储层展布问题，以最具代表意义的轴向水道——琼东南盆地中央峡谷为例，应用地质与地震相结合分析技术、多属性融合技术、适用于峡谷水道体系的地震沉积学等，开展了具有针对性的物源体系、沉积演化、储层展布等方面的研究，阐明了中央峡谷水道的物源、沉积演化及优质储层展布规律，建立了具有储层预测功能的峡谷沉积模式及水道砂叠置方式，指出乐东10-1峡谷水道等4个潜在的大型岩性圈闭群是轴向水道领域的下一步勘探有利区域，提升了轴向水道勘探潜力。

Channel sandstone is the most important oil and gas reservoir type in deep-water sedimentary systems. A large-scale axial channel deposition system is present in the Yinggehai and Huangliu Formations in the Ying-Qiong Basin. Axial channels are considered an important area for oil and gas exploration in the Ying-Qiong basin, and are valued by domestic and international companies. However, due to a lack of systematic understanding of the formation mechanism and distribution of sandstones in such axial channels, exploration thus far has been unable to yield a commercial breakthrough. This study aimed to resolve issues of provenance and reservoir distribution, which have restricted the exploration of axial channel depositional systems. The central valley, which is the most representative axial channel in the Qiongdongnan Basin, was taken as an example. Combined geological and seismic analysis, multi-attribute integration technology, seismic sedimentology, and other new technologies suited to canyon channel systems were applied in this study. We then carried out targeted research on the provenance system, sedimentary evolution, and reservoir distribution, thereby clarifying the provenance, sedimentary evolution and quality reservoir distribution patterns of the central valley channel. We have also established a sedimentation model and channel sandstone superimposition method for the central valley, which could be used to predict the structure of the reservoir. Our results revealed the existence of four potential large lithologic traps, such as in the Ledong 10-1 Valley channel. These areas are favorable for the next step of exploration of axial channels, thus greatly enhancing their exploration potential.

10.11885/j.issn.1674-5086.2015.12.31.01