印度东部盆地群地质特征、油气成藏与深水区勘探潜力  

Geological features,hydrocarbon accumulation and deep water potential of East Indian basins

作　　者：秦雁群[1] 张光亚[1] 计智峰 李志[1] 吴义平[1] 王兴龙 梁旭 

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中海油研究总院,北京100028

出　　处：《石油勘探与开发》2017年第5期691-703,共13页Petroleum Exploration and Development

基　　金：国家油气重大专项(2016ZX05029005);中国石油天然气集团公司科技项目(2016D-43)

摘　　要：基于印度东部盆地群区域构造沉积演化、地层充填和油气地质特征,建立深水扇体发育和成藏模式,分析深水区勘探潜力。印度东部被动大陆边缘形成源自东冈瓦纳古大陆裂解,经历了克拉通内裂谷(P_1—T)、东冈瓦纳裂谷(J_1—K_1)、裂后热沉降(K_2)和被动大陆边缘(K_3—N)4个演化阶段,发育裂后热沉降期末、被动大陆边缘I期末和Ⅱ期末3个明显不整合,形成裂谷期和被动大陆边缘Ⅰ期、Ⅱ期、Ⅲ期4套构造层,被动大陆边缘阶段沉积是盆地群地层主体,形成近岸叠覆型扇复合体、与三角洲有关的断裂坡折部位低位扇和前缘浊积扇两类富油气沉积体系。盆地内发育下二叠统、下白垩统、上白垩统和古近系4套证实的烃源岩,平面分布差异大;发育裂谷期砂岩和碳酸盐岩、裂后热沉降和被动大陆边缘时期三角洲和深水重力流砂岩等多种类型储集层,总体为中孔、低渗条件;油气盖层多、厚度变化大,漂移期多为区域封盖,其他时期则以局部封盖为主;形成上白垩统砂岩、古近系砂岩、新近系砂岩等8个成藏组合。被动大陆边缘阶段深水区油气勘探在平面上应以克里希那和高韦里河流三角洲地区为主,纵向上则以被动大陆边缘阶段与构造相关三角洲砂体、断裂坡折处低位扇、85°E海脊附近和高韦里盆地南部海域近岸扇复合体为重点。Based on the tectonic evolution, sedimentary filling and hydrocarbon geological characteristics, this paper establishes a variety of deep water fan models and accumulation patterns and analyzes exploration potential of deep water area in East Indian basins. Due to the breakup of East Gondwana, the passive continental margins of East India are evolved. The basins in these margins experienced four evolution stages, which include intracratonic rift （P1-T）, East Gondwana rift （J1-K1）, post-rifted thermal subsidence （K2）, and passive continental margin （K3-N）. There are three obvious unconformities which were formed in the end stages of post-tiff thermal subsidence and first and second phases of passive continental margin. Four sets of structural layers were formed, rift stage, and the first, second and third stages of passive continental marginal structural formation. The main deposition of these basins is the sediments evolved during the passive continental margin stage. Two prolific fan systems were developed： superposition fans are complicated in near shore and delta; low fans are located at fault slope-break while turbidity fans are located in front of delta. Four sets of proven source rocks were developed the Lower Permian, Lower Cretaceous, Upper Cretaceous and Paleogene. There are many middle porosity reservoirs and low permeability reservoirs, such as sandstone and local carbonate in rift period, sandstone of delta and deep water gravity flow in the rifted thermal subsidence and passive continental margin stages. Many seals were developed in the basins, regional seals in drifted stage and local seals in other stages, and the seals thickness change are enormous. There are eight plays in these basins which include Upper Cretaceous sandstone, Paleogene sandstone, Neogene sandstone, etc. The hydrocarbon exploration of deep water area during the passive continental margin stage should focus on Krishna and Cauvery river delta on the plane, and delta sandstone related to fault, low fan located at f

关 键 词：被动大陆边缘 深水油气勘探 深水扇 三角洲 默哈讷迪盆地 克里希那—戈达瓦里盆地 高韦里盆地 印度东部 

分 类 号：TE122.2[石油与天然气工程—油气勘探]