珠江口盆地陆坡类型及其对深水储层的控制  

Slope types and their controlling effects on deep-water reservoir in the Pearl River Mouth basin

作　　者：徐少华[1,2] 王英民[1,3] 何敏 杜家元 徐国强[5] 陈维涛 魏文杰[1,2] 陈晨[1,2] XU Shaohua WANG Yingmin HE Min DU Jiayuan XU Guoqiang CHEN Weitao WEI Wenjie CHEN Chen(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum （Beijing）, Beijing 102249, China College of Geoscienees, China University of Petroleum （Beijing）, Beijing 102249, China Ocean College, Zhej iang University, Hangzhou, Zhejiang 310058, China Shenzhen Branch of CNOOC Ltd, Guangzhou, Guangdong 510240,China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu,Sichuan 610059 ,China)

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [2]中国石油大学(北京)地球科学学院,北京102249 [3]浙江大学海洋学院,浙江杭州310058 [4]中海石油(中国)有限公司深圳分公司,广东广州510240 [5]成都理工大学油气藏地质及开发工程国家重点实验室,四川成都610059

出　　处：《中国矿业大学学报》2016年第5期982-992,共11页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(41372115);国家重点基础研究发展计划(973)项目(2009CB219407)

摘　　要：为了寻找陆架边缘三角洲和深水扇之间的对应关系,利用三维地震资料解释、沿层属性提取和钻测井信息,探讨珠江口盆地白云凹陷晚渐新世(23.8 Ma)、早中新世(21 Ma)和中中新世(13.8Ma)的陆坡类型和演化.根据陆坡发育侵蚀水道的规模将其分为侵蚀型、侵蚀-加积型和加积型3类.研究结果表明:侵蚀型陆坡(21Ma)发育大规模的下切峡谷,平面上呈顺直-蛇曲型,剖面上为U型或V型的强振幅反射.峡谷内部充填富砂质的碎屑流或浊流沉积,天然堤不发育;峡谷末端发育大型深水扇朵体.侵蚀-加积型陆坡(23.8Ma)发育规模明显小于峡谷的冲沟,与冲沟相连的盆底扇规模减小.加积型陆坡(13.8 Ma)难以识别侵蚀水道.陆坡以粉砂岩和泥岩的披覆沉积为主,低密度浊流或异重流为主要的搬运机制,沉积物在非限制性环境下大多沉积在中—上陆坡区,难以搬运至深水盆地.强烈的构造活动和近物源易于诱发陆坡沉积物的垮塌,是侵蚀型陆坡形成的主要原因.稳定的构造沉降、欠补偿或补偿环境、远离主河口、弱的水动力条件以及海平面持续下降但不低于陆架坡折是加积型陆坡的成因.仅依靠陆架边缘三角洲的发育尚不能对深水储层是否大规模发育做出判断,而伴随海平面持续下降形成的陆坡侵蚀峡谷是深水储层发育的重要保障.To find the relationship between the shelf margin delta and the deep-water fan, by using 3D seismic interpretation, horizon attribute extraction and well-log data, slope types and evolution features of Baiyun sag in Pearl River Mouth basin at late Oligocene （23.8 Ma）, early Miocene （21 Ma） and middle Miocene （13. 8 Ma） were discussed. According to the scale of erosional channels, slopes can be divided into 3 types, including erosional, erosional-accretionary, and accretionary style. The results show that the erosional slope （21 Ma） with a largescale of incised canyons appears rectilinear or little meandering spaced in the horizontal plane and shows a U-shaped or V-shaped strong amplitude reflection in cross sections. The interior of canyons are filled with sand-rich debris flow deposits or turbidity sediments, with less levee deposits. Large deep-water fan lobes are connected to canyons termination. The scale of gullies systems in the erosional-accretionary slope （23.8 Ma） is significantly smaller than the canyons, and the scale of basin-floor fan connecting to gullies is smaller. However, it is difficult to identify erosional channels in accretionary slope （13.8 Ma）. The slope sediments are mainly silts and mudstone. The main transporting mechanism is the hyperpycnal flow or low-density turbidity. Sediments in the unconstrained environment are difficult to be transported to deep-water basin. The slope failure, which is induced by intense tectonic activities and the location near estuary, is the cause for the formation of erosional slopes. Stable tectonic subsidence, underfilled or filled environment, long-distance from the main estuary of Paleo-Pearl River, weak hydrodynamic conditions and the sea level falling continuously but not below the shelf break lead to the formation of the accretionary slope. The existence of shelf margin delta cannot be a criterion of large-scale deep-water reservoir development, but the slope erosional canyons formed in the continuous falling process of the sea

关 键 词：珠江口盆地 白云凹陷 陆架边缘三角洲 陆坡 深水扇 

分 类 号：TE51[石油与天然气工程—油气田开发工程]