摘要
中国是世界上少有的几乎每个地质时代都有白云岩分布的国家。从华北地区的元古宇到第四系的盐湖沉积物,都能见到各种类型的白云岩(石),但白云岩在层位和区域上分布不均,类型上也有明显差异。其中,下古生界白云岩分布最为普遍,而上古生界、中生界和新生界仅有局部地区发育白云岩。中国白云岩的类型和与之相对应的白云岩化作用主要有:微生物(生物)白云岩化、萨布哈白云岩化、回流渗透白云岩化、热液白云岩化和混合水白云岩化。由于白云岩化作用是一个持续或断续的、复杂的过程,即使同一层系的白云岩也会经历多期次、多类型白云岩化作用的叠加改造。白云岩是中国重要的油气储层,其类型多、形成时间跨度大。在深层和古老海相层系之中,白云岩比灰岩更易于形成优质的油气储层,由此其重要性显得更为突出。在晚古生代和中、新生代形成的湖相白云岩也具有很好的储集性能,是非常规油气的重要赋存场所。白云岩储层按照其形成主控因素可以大致分为4种基本类型:相控准同生溶蚀型、面控表生溶蚀型、断控深埋改造型和深埋生烃溶蚀型。白云岩储层形成和保持受构造、层序、岩相、流体和时间五因素的联合、复合作用所控制。这些因素和成储机制的差异,造就了白云岩储层发育展布的多样性。
China is one of the few countries in the world where dolomites were developed throughout its geological age.Various types of dolomites can be found from the Proterozoic in North China to the Quaternary salt lake sediments,but the distribution of dolomites is uneven along stratigraphy and across region,with also a great variety in types.The dolomites are widespread in the Lower Paleozoic but become more local features in the Upper Paleozoic,Mesozoic and Cenozoic.The types of dolomitization mainly include microbial(biological),Sabkha,reflux seepage,hydrothermal and mixing zone dolomitization.Because dolomitization is a complicated,long term or intermittence process,even dolomites of the same strata would undergo multiple stages of dolomitization with several types superimposed.Dolomite reservoir is an important oil and gas reservoir in China,featuring variety in types and large time span.In the deep and ancient marine strata series,dolomite is more prone to generate high-quality oil and gas reservoirs compared with limestone.So its importance is even more prominent.Lacustrine dolomites formed in the Late Paleozoic and Meso-Cenozoic are also good in reservoir properties,serving as important reservoirs of unconventional oil and gas.The formation and preservation of dolomite reservoirs are jointly controlled by structure,sequence,lithofacies,fluid,and time.Altogether four types of controlling factors are identified herein:sedimentary facies-controlled para-syndepostional dissolution,ground surface-controlled shallow karstification,fault-controlled reformation in deep burial and deeply buried hydrocarbon dissolution.In all,the factors mentioned,together with different reservoir space generation and accumulation mechanisms,collectively decide the wide type spectrum and the complicated distribution patterns of dolomite reservoirs.
作者
何治亮
马永生
张军涛
朱东亚
钱一雄
丁茜
陈代钊
He Zhiliang;Ma Yongsheng;Zhang Juntao;Zhu Dongya;Qian Yixiong;Ding Qian;Chen Daizhao(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,SINOPEC,Beijing 100083,China;China Petroleum&Chemical Corporation,Beijing 100728,China;Laboratory of Structural and Sedimentological Reservoir Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 100083,China;Key Laboratory of Petroleum Resource Research,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)
出处
《石油与天然气地质》
EI
CAS
CSCD
北大核心
2020年第1期1-14,共14页
Oil & Gas Geology
基金
国家自然科学基金重点资助项目(U1663209)
国家自然科学基金企业创新发展联合基金项目(U19B6003)
国家科技重大专项(2017ZX05005)
中国科学院A类战略性先导项目(XDA14010201)
