四川盆地上奥陶统五峰组—下志留统龙马溪组页岩是中国目前页岩气勘探开发的重点层系之一,已发现了涪陵、威远、长宁和昭通等页岩气藏。通过页岩气藏的详细解剖,将五峰组—龙马溪组下部龙一段页岩气富集特征概括为“高、帅、富”:“高”主要指页岩层系形成页岩气的原始物质基础条件优越,有机质类型好、丰度高、脆性矿物含量高、热演化程度适中;“帅”主要表现为构造变形较晚、变形强度较弱、变形方式与构造样式有利、抬升幅度以及现今埋深适中;“富”表现为含气量高、地层压力系数大、储层物性好、有利于储层规模改造、初始产量高、最终产出量大,开发难度相对较小,经济效益明显。优越的原始沉积条件与成岩过程(地质建造作用)与后期适度的构造变形改造与抬升剥蚀(地质改造作用)的有机组合,是页岩气的富集高产前提与关键。基于“建造”(生—储演化序列)的评价内容包括层序地层与沉积、生烃和储层孔隙形成3个方面内容,基于“改造”(储—保演化序列)的评价内容主要包括构造变形、储层裂缝形成和页岩气保存2个方面。“建造—改造”的评价思路就是沿着页岩气形成与保存的全过程,既分析页岩气形成的建造条件优劣,又评价构造改造方式、程度的正面、负面影响。基于这种评价思路所建立的各种评价要素的组合模型,更符合页岩气形成与富集规律,也能更有效地消除简单将各种要素不作区别地统一纳入评价体系所带来的偏差。 Upper Ordovician Wufeng Formation - Lower Silurian Longmaxi Formation Shale in the Sichuan Basin is one of the key strata in shale gas exploration and development in China. Shale gas reservoirs such as Fuling, Weiyuan, Changning and Zhaotong have been discovered. Through the detailed dissection of shale gas reservoirs, the enrichment characteristics of shale gas in the lower part of the Longfeng Formation of the Wufeng-Longmaxi Formation are summarized as follows: “high, handsome, rich”: “high” mainly refers to shale formation shale The original material of gas has superior basic conditions, good types of organic matter, high abundance, high content of brittle minerals and moderate degree of thermal evolution. “Shuai” is mainly characterized by late tectonic deformation, weak deformation strength and favorable deformation and tectonic pattern , The extent of the lift and the current depth of the buried depth; “rich ” is manifested as high gas content, formation pressure coefficient, reservoir physical properties, is conducive to the reservoir scale transformation, the initial output is high, the final output is large, the relative difficulty of development Small, obvious economic benefits. Superior combination of primary sedimentary conditions and diagenesis (geological construction) with moderate structural deformation and uplifting and denudation (geological modification) at the later stage are the prerequisite and key for enrichment of shale gas. The evaluation based on “build ” (bio-reservoir evolution sequence) includes three aspects: sequence stratigraphy and sedimentation, hydrocarbon generation and reservoir pore formation. The evaluation based on “transformation ” Main contents include tectonic deformation, formation of reservoir fractures and shale gas preservation. “Construction - Transformation ” evaluation idea is along the whole process of shale gas formation and preservation, both the pros and cons of the formation of shale gas analysis of construction conditions, but also evaluate the structural transformation methods, the degree of positive and negative impact. The combination model of various evaluation elements established based on this kind of evaluation mentality is more in line with the rule of shale gas formation and enrichment and can more effectively eliminate the deviation caused by simply integrating various factors into the evaluation system without any distinction .