克拉通盆地构造分异对大油气田形成的控制作用——以四川盆地震旦系—三叠系为例  

Control of tectonic differentiation on the formation of large oil and gas fields in craton basins:A case study of Sinian–Triassic of the Sichuan Basin

作　　者：汪泽成[1] 赵文智[1] 胡素云[1] 徐安娜[1] 江青春[1] 姜华[1] 黄士鹏[1] 李秋芬[1] Wang Zecheng Zhao Wenzhi Hu Suyun Xu Anna Jiang Qingchun Jiang Hua Huang Shipeng Li Qiufen(PetroChina Petroleum Exploration and Development Research Institute, Beijing 100083, China)

机构地区：[1]中国石油勘探开发研究院

出　　处：《天然气工业》2017年第1期9-23,共15页Natural Gas Industry

基　　金：国家科技重大专项"下古生界-前寒武系碳酸盐岩油气成藏规律;关键技术及目标评价"(编号:2016ZX05004-001)

摘　　要：克拉通盆地是中国海相碳酸盐岩油气赋存的主体,但过去在古老克拉通盆地构造分异对海相碳酸盐岩油气田形成与分布的影响方面缺少系统的研究,导致碳酸盐岩油气勘探有利区带评价优选难度大。为此,基于多年来对四川盆地震旦系—三叠系原型盆地与岩相古地理的研究成果,遵循构造控制沉积及油气分布的思路,分析了克拉通盆地的构造分异型式及其对油气成藏要素与分布的控制作用。结果表明:①克拉通内裂陷控制了优质烃源岩及生烃中心,与侧翼台缘带优质储集体构成良好的源—储组合,近源成藏条件优越;②克拉通内发育的差异剥蚀型、同沉积型、褶皱型3类古隆起及深大断裂,有利于碳酸盐岩规模储层的形成与分布;③多期、多类型构造分异的叠合区有利于形成大油气田。结论认为:四川盆地海相碳酸盐岩油气勘探潜力巨大,具有有利油气成藏条件的德阳—安岳裂陷东翼台缘带震旦系灯影组、川中古隆起斜坡区下寒武统龙王庙组、川中—川西地区中二叠统茅口组等是该盆地天然气勘探的新领域,值得重视。Craton basins are the main sites where marine carbonate oil and gas are accumulated in China. However, the previous studies scarcely focused on the control of tectonic differentiation on the formation of large oil and gas fields in the ancient craton basins. In such circumstances, it is difficult to evaluate and select the favorable zones for the exploration of carbonate oil and gas. In this paper, based on the research results of the Sinian-Triassic prototype basin and lithofacies paleogeography of the Sichuan Basin, the tectonic differentiation pattern of craton basins and its controls on the accumulation elements and the distribution of hydrocarbons were analyzed with reference to the concept that structures control the sedimentation and distribution of oil and gas. The study reveals the results in three aspects. First, the intra-craton rift controls the high-quality source rocks and the hydrocarbon generation center, which forms good source-reservoir assemblage with the high-quality reservoir in the platform margin at the flank, showing excellent near-source accumu- lation conditions. Second, the three types of paleo-uplift （i.e. differential denudation, syn-depositional, and folding） and the deep large fault developed in the craton are favorable for the formation and distribution of large-scale carbonate reservoirs. Third, the superimposed areas with tectonic differentiation in multiple periods and multiple types are favorable for the formation of large oil and gas fields. It is concluded that the marine carbonate rocks show a huge oil and gas exploration potential in the Sichuan Basin. Attention should be paid to the new exploration targets of natural gas, such as the Sinian Dengying Fm in the platform margin at the east flank of Deyang-Anyue rift, the Lower Cambrian Longwangmiao Fm in the slope of paleo-uplift in central Sichuan Basin, and the Middle Permian Maokou Fm in central-west Sichuan Basin, where oil and gas accumulation conditions are favorable.

关 键 词：四川盆地 构造分异 克拉通内裂陷 同沉积古隆起 差异剥蚀型古隆起 碳酸盐岩 震旦纪—三叠纪 勘探新区 

分 类 号：P618.13[天文地球—矿床学]