基于热模拟的页岩矿物及孔隙演化特征研究——以东营凹陷利页1井沙三下亚段为例  

Evolution characteristics of shale minerals and pores based on thermal simulation—by taking the lower Es3 member of Shahejie formation in well Liye 1 of Dongying sag an example

作　　者：周永 吴伟[1] 张琳 刘惟庆[1] 冯阵东[2] ZHOU Yong;WU Wei;ZHANG Lin;LIU Weiqing;FENG Zhendong(Institute of Resource&Environment,Henan Polytechnic University,Jiaozuo,Henan454000,China;Institute of Science and Engineering,Henan Polytechnic University,Jiaozuo,Henan 454000,China)

机构地区：[1]河南理工大学资源环境学院,河南焦作454000 [2]河南理工大学安全科学与工程学院,河南焦作454000

出　　处：《石油地质与工程》2022年第6期49-56,共8页Petroleum Geology and Engineering

基　　金：国家自然科学基金项目(42002031)。

摘　　要：储集空间分布特征是页岩油气勘探描述的重点内容之一,不同深度的油页岩受成岩、压实、有机质生烃等因素共同影响,造成孔隙、裂缝等油气储集空间发生变化,观察热模拟过程中矿物及孔隙的演化特征,可以为页岩储集空间演化机理研究提供参考。本文以东营凹陷利页1井沙河街组沙三下亚段的纹层状富有机质页岩为研究对象,通过热模拟、氩离子抛光-扫描电镜和图像分析等手段,分析不同温度条件下页岩矿物和孔隙的演化特征。结果表明,随热模拟温度的增加页岩面孔率增高,在模拟范围内矿物相关孔隙的发育与温度有关,敏感性从低到高分别为:石英、方解石、有机质、黄铁矿、黏土矿物和白云石;利页1井页岩孔隙主要包括粒内孔、粒间孔、黏土矿物收缩缝、有机质孔,以及少量的生物腔体孔,成熟-高熟阶段以粒间孔、粒内孔为主,高熟-过熟阶段以微裂隙和粒内孔为主;在高温高压条件下,矿物的溶蚀溶解形成了以0.1~1.0μm孔径为主的储集空间,推测是由于有机酸的生成和黏土矿物催化,加剧了矿物的溶解溶蚀。Reservoir spatial distribution is one of the key contents of shale oil and gas exploration description.Oil shale at different depths is affected by diagenesis,compaction,organic matter hydrocarbon generation and other factors,resulting in changes in pore,fracture and other oil and gas reservoir space.Observing the evolution characteristics of minerals and pores in thermal simulation can provide a reference for the study of shale reservoir space evolution mechanism.By taking the laminar organic-rich shale in the lower Es3 member of Shahejie formation in well Liye 1 of Dongying sag as an example,the evolution characteristics of shale minerals and pores at different temperatures were analyzed by means of thermal simulation,Argon ion polishing-scanning electron microscopy and image analysis.The results show that the shale surface porosity increases with the increase of thermal simulation temperature,and the development of mineral-related pores in simulation range is related to temperature,and the sensitivity from low to high is:quartz,calcite,organic matter,pyrite,clay minerals and dolomite.The shale pores in Well Liye 1 mainly include intragranular pores,intergranular pores,clay mineral shrinkage cracks,organic pores,and a small amount of biological cavity pores.Intergranular pores and intragranular pores are dominant in the mature-high maturity stage,while microcracks and intragranular pores are dominant in the high-maturity to over-mature stage.Under high temperature and pressure,the dissolution of minerals forms a reservoir space with a pore size of 0.1-1μm.It is supposed to be caused by the formation of organic acids and the catalysis of clay minerals,which aggravates the corrosion and dissolution of minerals.

关 键 词：东营凹陷 热模拟 显微特征 矿物演化 孔隙演化 

分 类 号：P618.13[天文地球—矿床学]