沉积岩中自生浊沸石的形成、分布及油气意义——以鄂尔多斯盆地中—上三叠统延长组为例  

Formation and distribution of laumontite in sedimentary sequences and their exploration significance——A case study on the Middle—Upper Triassic Yanchang Formation in Ordos Basin

作　　者：王龙[1,2] 邓秀芹[1,2] 楚美娟[1,2] 张忠义[1,2] 任肇才[1,2] 刘广林[1,2] 张文静[1,2] 齐亚林[1,2] WANG Long;DENG Xiuqin;CHU Meijuan;ZHANG Zhongyi;REN Zhaocai;LIU Guanglin;ZHANG Wenjing;QI Yalin(Research Institute of Exploration and Development,PetroChina Changqing Oil Field Company,Xi’an,710018;National Engineering Laboratory for Exploration and Development of Low Permeability Oil and Gas Fields,Xi’an,710018)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,西安710018 [2]低渗透油气田勘探开发国家工程实验室,西安710018

出　　处：《地质论评》2022年第6期2188-2206,共19页Geological Review

基　　金：国家科技重大专项(编号:2017ZX05001002);中国石油天然气股份有限公司前瞻性研究项目(编号:2021DJ2203)的成果。

摘　　要：自生浊沸石矿物在以岩屑长石砂岩和长石砂岩为主的陆相湖盆储集层中广泛发育,我国几乎所有含油气盆地都有关于浊沸石砂岩储层的报道,自生浊沸石的特征、分布、成因及油气意义亟需系统总结归纳。笔者等在系统梳理前人成果的基础上,以鄂尔多斯盆地上三叠统延长组为例,通过野外剖面、岩芯薄片、扫描电镜、能谱分析等手段,结合浊沸石成因演化理论模型和鄂尔多斯盆地区域演化史,明确了延长组浊沸石的岩石学特征、成岩演化、成因机制和时空分布规律。发现自生浊沸石是一种容易在低温碱性成岩环境下形成的富钙的水铝硅酸盐胶体矿物,相对密度小、抗压易溶、对成岩环境敏感,在特定条件下可作为成储、成藏过程中的示踪矿物。其次生优质溶蚀相储集层时间上主要处于中成岩期A阶段,空间上主要受控于物源、沉积相带和邻近的烃源岩及输导体沟通下的成岩流体作用。并基于上述认识,对鄂尔多斯盆地延长组长10的下步勘探评价提供了理论依据和优选了有利目标。Objectives:Authigenic laumontite cements are widely developed in continental lake basin reservoirs dominated by lithic arkose and arkose,which have been reported in almost all petroliferous basins in China.Therefore,to review and summarize the characteristics,origin and distribution of laumontite is not only of great theoretical value,but also of great significance for oil and gas exploration.The rich well data and diverse depositional environments of Yanchang Formation in Ordos Basin lay a good foundation for the study of authigenic laumontite in sedimentary sequences,so we study the formation,distribution and its exploration significance of laumontite by taking Yanchang Formation in Ordos Basin as an example.Methods:The thin sections,scanning electron microscope and energy spectrum were analyzed combined with outcrops observation,as well as the theoretical model of laumontite genesis and the regional evolution history of Ordos Basin,to illustrate the petrological characteristics,diagenetic evolution,genetic mechanism and temporal and spatial distribution characteristics of laumontite in Yanchang formation.Results:It is found that laumontite can be used as a tracer mineral in the process of reservoir formation under specific conditions,because of its relative low density,easy dissolution but resist to pressure,and sensitive to diagenetic environment.It would fill the pores as cement in the alkaline environment from early to early middle diagenetic stage,while it would dissolve to produce a great quantity of secondary pores when diagenetic fluid changes into acidic for the organic acid produced by hydrocarbon expulsion.The secondary dissolution facies related to laumontite is controlled by middle diagenetic stage in time,and by provenance,sedimentary environments and diagenetic fluid related to source rocks and transport system in space.Conclusions:Based on the analysis of laumontite content,dissolution,relationship with reservoir physical properties and its implication of hydrocarbon accumulation,the favorable t

关 键 词：鄂尔多斯盆地 中—上三叠统延长组 浊沸石 成岩作用 油气勘探 

分 类 号：P618.13[天文地球—矿床学]