中国含油气盆地深层、超深层超压盖层成因及其与超大型气田的关系  

Formation mechanisms of deep and ultra-deep overpressure cap rocks and their relationships with super large gas fields in the petroliferous basins of China

作　　者：李伟[1] 喻梓靓 王雪柯 于志超[1] 鲁雪松[1] 冯庆付[1] LI Wei;YU Ziliang;WANG Xueke;YU Zhichao;LU Xuesong;FENG Qingfu(PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;Beijing Research Center,CNOOC China Limited,Beijing 100011,China)

机构地区：[1]中国石油勘探开发研究院,100083 [2]中海石油(中国)有限公司北京研究中心,100083

出　　处：《天然气工业》2020年第2期11-21,共11页Natural Gas Industry

基　　金：国家科技重大专项“前陆冲断带及复杂构造区油气成藏、分布规律与有利区评价”（编号：2016ZX05003-002）

摘　　要：进入21世纪以来,中国陆上与海域含油气盆地的深层、超深层持续发现超大型天然气田,并且已有大量的文献对该类气田形成的地质条件与发育规律进行了探讨,然而对于其形成与超压的关系则研究较少。为此,在分析深层、超深层超大型气田的气藏发育规律、封盖条件、超压特征等的基础上,研究了深层、超深层超压盖层的形成机制,探讨了深层、超深层超大型气田的发育规律及其与超压盖层的关系,进而指出了下一步深层、超深层天然气勘探的有利领域。研究结果表明:(1)深层、超深层超大型气田的形成与超压盖层的发育密不可分,超压盖层是深层、超深层超大型气田形成的必备条件,并且存在着盐膏层压力封闭、隆升残留压力封存、生烃增压压力封闭等3种超压形成机制;(2)深层、超深层超压盖层与超大型气田存在着4种不同压力环境下的储—盖组合模式,即:超高压盐膏层封盖与超高压超大型气田(Ⅰ型)、超高压封存箱内幕与超高压超大型气田(Ⅱ型)、超高压封存箱底部高压泥页岩封盖与常压超大型气田(Ⅲ型)、超压烃源岩封盖与常压超大型气田(Ⅳ型)。结论认为,塔里木盆地库车坳陷存在着Ⅰ型,准噶尔盆地存在着Ⅱ、Ⅲ型,四川盆地存在着Ⅰ~Ⅳ型,渤海湾盆地存在着Ⅳ型等不同类型的超大型气田。Super large natural gas fields have been discovered in the deep and ultra-deep layers of onshore and offshore petroliferous basins in China since the beginning of the 21 st century, and the geological conditions for the formation of these gas fields and their de- velopment laws have already been discussed in a large number of literatures, but the relationship between overpressure and the formation of this kind of gas fields is still less researched. In this regard, this paper firstly analyzed the gas reservoir development law, sealing conditions and overpressure characteristics of deep and ultra-deep super large gas fields. Then, the formation mechanisms of deep and ultra-deep overpressure cap rocks were investigated and the development law of deep and ultra-deep super large gas fields and their rela- tionship with overpressure cap rocks were discussed. Finally, the favorable areas for the next exploration of deep and ultra-deep natural gas were pointed out. And the following research results were obtained. First, the formation of deep and ultra-deep super large gas fields is closely related to the development of overpressure cap rocks. Overpressure cap rock is a necessary condition for the formation of deep and ultra-deep super large gas fields, and there are three overpressure formation mechanisms, including pressure seal of salt-gypsum layer, pressure seal of residual uplift and pressure seal of hydrocarbon-generating pressurization. Second, as for deep and ultra-deep over- pressure cap rocks and super large gas fields, there are four reservoir-cap rock assemblage modes under different pressure environments, i.e., overpressure salt-gypsum seal and overpressure super large gas field (type I), internal overpressure compartment and overpressure super large gas field (type II), high-pressure argillaceous shale seal at the bottom of overpressure compartment and normal-pressure super larger gas field (type III), and overpressure source rock seal and normal-pressure super larger gas field (type IV). In conclusion, th

关 键 词：深层 超深层 超压盖层 成因 超大型气田 塔里木盆地 准噶尔盆地 四川盆地 渤海湾盆地 

分 类 号：P618.13[天文地球—矿床学]