辽西地区中生界下白垩统义县组火山岩相模式及储层意义  

Volcanic Facies Model and Reservoir Significance of Mesozoic Lower Cretaceous Yixian Formation in Western Liaoning

作　　者：张津铭 唐华风[1] 雷杭山 卞海越 贾万丽 高有峰[1] 孙雨颀 Zhang Jinming;Tang Huafeng;Lei Hangshan;Bian Haiyue;Jia Wanli;Gao Youfeng;Sun Yuqi(College of Earth Sciences,Jilin University,Changchun 130061,China;CNOOC Research Institute Co.,Ltd.,Beijing 100028,China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]中海油研究总院有限责任公司,北京100028

出　　处：《吉林大学学报（地球科学版）》2024年第6期2089-2113,共25页Journal of Jilin University：Earth Science Edition

基　　金：吉林省重点研发项目(20230203107SF);国家自然科学基金重大项目(41790453)。

摘　　要：岩相模式是火山岩油气藏研究的重要基础,对储层的预测和油气层评价有重要的指导意义。渤海海域中生界火山岩取得了重大突破,随着勘探工作的深入,其他区域的火山岩相模式在本区已不再适用。为了建立渤海海域下白垩统义县组火山岩相模式,为该区火山岩油气藏勘探开发提供依据,本文基于辽宁西部露头地质调查,利用岩矿鉴定、主微量元素分析、粒度分析和面孔率(或面缝率)分析方法,进行岩性、岩相和储层物性的综合研究。结果表明,辽西义县组火山岩就位环境存在陆上和水下两种。根据5相15亚相44微相分类方案,识别出3相5亚相9微相:爆发相,热基浪亚相,包括火山口-近火山口微相、近源微相和远源微相,热碎屑流亚相,包括火山口-近火山口微相;喷溢相,水上熔岩流亚相,包括简单熔岩流微相和复合熔岩流微相,水上喷发水下就位熔岩流亚相,包括复合熔岩流微相和原地碎屑堆积微相;侵出相,水上熔岩穹丘亚相,包括内核微相。储层面孔率(或面缝率)由高到低依次为爆发相、喷溢相和侵出相。热碎屑流亚相火山口-近火山口微相的储层物性优于热基浪亚相火山口-近火山口微相,且前者总面孔率(或面缝率)较大,水上喷发水下就位熔岩流亚相的储层物性优于水上熔岩流亚相。水上喷发水下就位熔岩流亚相原地碎屑堆积微相在所识别出的9种微相里储层最好。爆发相和喷溢相的亚相纵横比中等储层更好。Lithofacies model is an important basis for the study of volcanic oil and gas reservoirs and has important guiding significance for reservoir prediction and oil and gas reservoir evaluation.A major breakthrough has been made in Mesozoic volcanic rocks in Bohai Sea.With the deepening of exploration work,the inapplicability of volcanic facies models in other regions has become prominent in this area.In order to establish the volcanic facies model of Lower Cretaceous Yixian Formation in Bohai Sea,it provides a basis for the exploration and development of volcanic oil and gas in this area.There are abundant outcrop data in western Liaoning.Based on outcrop geological survey,the lithology,lithofacies and reservoir physical properties are comprehensively studied by means of rock and mineral identification,major and trace element analysis,particle size analysis and surface porosity analysis.The results are as follows,there are two kinds of volcanic emplacement environments in the Yixian Formation of western Liaoning Province:onshore and underwater.According to the classification scheme of five facies 15 subfacies 44 microfacies,three facies five subfacies nine microfacies are identified in this study,which are volcanic pyroclastic flow subfacies crater-near crater microfacies,base surge subfacies crater-near crater microfacies,near source microfacies and far source microfacies;Effusive facies subaerial lava flow subfacies simple lava flow microfaciesand composite lava flow microfacies,effusive facies subaqueous lava flow subfacies composite lava flow microfacies and autochthonous debris accumulation microfacies;Extrusive facies lava dome above water subfacies core microfacies.From high to low,the reservoir surface porosity is explosive facies,effusive facies and extrusive facies.The physical properties of the volcanic crater-near-volcanic microfacies of the pyroclastic flow subfaciesare better than those of the volcanic crater-near-volcanic microfacies of the base surgesubfacies,and the total surface porosity is larger.

关 键 词：火山岩相 储层 面孔率 义县组 下白垩统 辽西 

分 类 号：P586[天文地球—岩石学] P618.13[天文地球—地质学]