【作者】 吴世祥；

【导师】 邓宏文；

【作者基本信息】 中国地质大学（北京） ， 矿产普查与勘探， 2003， 博士

【摘要】 本文以成藏为主线，从前陆盆地形成演化、构造变形、沉积充填、水文地质研究出发，以盆地模拟、含油气系统研究为手段，通过典型气藏的解剖和成藏主控因素分析，以及与国内外前陆盆地成藏特征对比，探讨川西前陆盆地油气富集规律和成藏特征，并预测有利勘探区带和方向。主要取得如下成果： 1、构造研究表明川西坳陷形成与形变主要受控于龙门山造山带，表现为坳陷内部南、北段构造特征、形成期及其变形方式上的差异。在绵阳—新场、梓潼一带存在横向断层发育带，裂缝发育，为高产气井分布区。 2、提出了川西前陆盆地的层序地层模式，认为川西前陆盆地一个完整的陆相层序是由湖盆边缘冲积体系域、湖侵体系域和湖泊高水位体系域三部分构成。 整个上三叠统由四个层序组成，其中三个为海相层序、一个为陆相层序。 3、通过对前述动、静态因素及油气分布规律的分析，结合烃源岩分布与地化特征、油气成藏模拟结果和水化学、水动力特征研究，首次明确将川西前陆上三叠统-侏罗系划分成三个油气系统，即须一-须二(!)、须三-须四(!)和须五-侏罗系(!)含油气系统。 三个系统的平面分布、有利区带展布和成藏主控因素具显著差异。 4、川西坳陷侏罗—白垩系、须二段和须四下段分属三个独立的含水系统。首次提出地下水地球化学动力带的概念，并系统研究了其分带特征。指出高压含气构造主要分布在水压形成带；中坝、平落坝、合兴场、八角场等气田处于稳压带和卸压带。 提出了灌口—平落坝和大兴鼻状构造带为最有利水文带；老关庙—九龙山低幅隆起带南段、孝泉—丰谷隆起带和温江—什邡坳陷带为有利水文带。 5、前陆盆地成藏研究表明，烃源岩分布与演化、储层分布、燕山期古隆起、断裂-裂缝分布、保存条件是川西前陆天然气富集的关键。 6、龙门山山前冲断带具有较大的油气潜力，构造圈闭、构造-裂缝型圈闭发育，中浅层构造同步发育或有断裂沟通，具有中浅层均含气的特征。因此，具有中、浅层构造立体勘探的价值。 7、前陆坳陷内源岩丰富、砂体发育，砂、页岩常呈指状交互，形成极为有利的储盖组合，可形成地层圈闭、岩性圈闭油气田或深盆气田。川西前陆凹陷区存在形成深盆气的几乎所有条件。大邑-绵竹、三台-梓潼-苍溪-仪陇一带具有勘探深盆气的潜力。 8、前缘斜坡带位于前渊坳陷向台地的过渡段，成藏条件优越。川西前陆隆起与斜坡区存在构造-地层圈闭勘探区；须二上倾尖灭带有利形成岩性上倾尖灭圈闭和油气藏。更多还原

【Abstract】 The exploration potential of the upper Triassic Xujiahe Formation in the western Sichuan Foreland Basin is great.By means of the technologies of Basin Modeling, Petroleum System, and correlation among Chinese and foreign basins, and integrated analysis of the features of evolution of the basin, tectonic transformation, sidmentology, hydrology, and the anatomising of typical gas pools, The paper focused on the poolforming features of the basin, probed into the characteristics of enrichment, distribution and poolforming of oil and gas, and forecasted the favorable areas or belts of exploration. At the same time, attained following fruits:1. The tectonic analysis indicated that the distortion of the foreland basin was mainly attributed to the movements of Longmen Mountains, the structural features, forming periods, and transformation fashions are different between the northern and southern segments. And in the middle segment, landscape orientation faults exist.2. The paper put forward the particular mode of Sequence Stratigraphy in the foreland basin, which includes Lacustrine Margin Alluvial Systems Tract(AST), Lacustrine Expanding Systems Tract(LTST),and Lacustrine Highstand Systems Tract (LHST). The upper Triassic can be divided into three marine and one nonmarine sequences.3. By the integrating analysis of static and dynamic factors and distributions of oil and gas, combined with the researches on the source rocks and their geochemical features, basin modeling, and chemic and dynamic features of underground water, the paper brought forward clearly that there are three petroleum systems in the upper Triassic, which are T3x1- T3x2(!), T3x3~ T3x4(!), and T3x5~ J(!). The distributing and promising prospects are different among them.4. The series of J~K, T3x2 and T3x4 belong to independent water bearing systems. By studying, the paper brought forward the concept of Dynamic Geochemical Belts, and indicated that the high pressure gas bearing structures distributed in the areas of hydraulic pressure forming belts, the gas fields, such as Zhongba, Pingluoba, Hexingchang and Bajiaochang, distributed mainly in the discharge and stabilization belts, Guankou-Pingluoba and Daxing nose are the most promising prospects, and Laoguanmiao-Jiulongshan, Xiaoquan-Fenggu and Wenjiang-Shifang are the favorite ones.5. The distributions of source rocks, reserviors and faults/fissures, and conservation are the critical factors in poolforming and enrichment of gas in the foreland basin.6. The thrust belts of Longmen Mountains are potential prospects in the basin with the concentrated structural traps, strucrural-fissuring traps, and faults connecting between the shallow and middle formations.7. The deep depression of the foreland basin, where reserviors and source rocks interfingered together, is promising areas for the exploration of Deep Basin Gas and stratigraphic traps. Especially in the territories of Dayi-Mianzhu, Santai-Zitong-Yilong.8. The stable Foreland Slope and Forebulge are promising areas of structure-stratigraphy and upper pinchout traps.更多还原