三塘湖盆地石炭系火山岩油气储层特征及碱性成岩作用  

Study on Characteristic of Carboniferous Volcanic Oil and Gas Reservoirs and Alkaline Diagenesis in the Santanghu Basin,NW China

作　　者：柳成志[1] 孙玉凯[2,3] 于海山[1] 杨文敏[1] 雷海艳[1] 

机构地区：[1]东北石油大学地球科学学院,黑龙江大庆163318 [2]吐哈油田分公司勘探开发研究院,新疆哈密839009 [3]中国科学院广州地球化学研究所,广州510640

出　　处：《吉林大学学报（地球科学版）》2010年第6期1221-1231,共11页Journal of Jilin University：Earth Science Edition

基　　金：中国石油天然气股份有限公司专题项目(2008B-0101)

摘　　要：利用岩心、薄片、扫描电镜、测井及储层物性资料,通过对三塘湖盆地石炭系火山岩储层特征的研究,得到以下认识:①岩性上以玄武岩、安山岩及其过渡岩性为主;②岩相上以溢流相为主,爆发相之碎屑流亚相及爆发相内部的'岩体内松散层'次之;③次生储集空间往往叠加在原生储集空间之上,孔、洞、缝交织在一起形成有效储集空间;④储层物性整体表现出以安山岩类最好、玄武岩类次之的特征;⑤由浊沸石化、钠长石化、钠铁闪石化、菱铁矿化和SiO2溶解现象证明了石炭系火山岩中碱性流体的存在,其碱交代作用使储层中矿物组分迁移,为储层形成奠定了矿物学基础;⑥碱性成岩作用在石炭系火山岩中普遍存在,其'上硅下碱'的垂向分带规律形成和保存了大量次生孔隙,为次生孔隙带的发育奠定了基础;⑦流体在储层形成过程中发挥了重要作用,本区石炭系火山岩储层的形成揭示了一种'碱性+酸性'叠加溶蚀的火山岩储层形成机理。Based on the data of core, thin section, scanning electron microscopy, well logging and the physical property of reservoir, we understand the following points according to the research about characteristics of the Carboniferous volcanic reservoirs in Santanghu basin. ① The lithology is mainly composed of basalt, andesite and transitional lithology; ②The lithofacies are based on overflow facies, with pyroclastic flow subfacies and inner loose layer of explosive facies;③Secondary storage space is often superimposed on the original storage space, and the pore, hole, slit together form the effective storage space;④The overall performance of the reservoir property shows that the andesite is the best, followed by the basalt; ⑤ The phenomena such as laumontitization, albitization, arfvedsonization, sideritation and SiO2 dissolving prove that the hydrocarbon alkali fluid is obtained in the Carboniferous volcanic rocks, and the mineral composition in the rocks migrate because of the alkali metasomatism, which offer the mineralogy basis for the formation of reservoir; ⑥ Alkaline diagenesis in the Carboniferous volcanic rocks is common,the vertical zoning laws of ＂alkali under the silicium＂ formed and preserved a large number of secondary porosity, which built up the foundation for the development of secondary pore zone;⑦Fluid plays an important role in the formation of reservoir. The formation of Carboniferous volcanic reservoirs in the study area shows the formation mechanism in volcanic reservoir is ＂acidity and alkali＂ superposition of dissolution.

关 键 词：三塘湖盆地 火山岩储层 碱性成岩作用 碱交代 次生孔隙带 油气 

分 类 号：P618.13[天文地球—矿床学]