准噶尔盆地阜东斜坡梧桐沟组储层沸石分布特征及成因机制  

Characteristics and genetic mechanisms of widely distributed zeolites in the Wutonggou Formation reservoir in the southern Junggar Basin

作　　者：史燕青[1,2] 季汉成[1,2] 张国一[3] 王剑[4] 宋兴国 刘尽贤 SHI Yanqing;JI Hancheng;ZHANG Guoyi;WANG Jian;SONG Xingguo;LIU Jinxian(College of Geosciences,China University of Petroleum-Beijing,Beijing 102249,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum-Beijing,Beijing 102249,China;Exploration&Development Research Institute,PetroChina Jilin Oilfield Company,Sonyuan 138000,China;Research Institute of Experiment and Detection,PetroChina Xinjiang Oilfield Company,Karamay 834000,China;Oil Production Plant of East China Branch Company,SINOPEC,Taizhou 225300,China)

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石油吉林油田勘探开发研究院,吉林松原138000 [4]中国石油新疆油田公司实验检测研究院,新疆克拉玛依834000 [5]中国石化集团华东油气分公司泰州采油厂,江苏泰州225300

出　　处：《石油科学通报》2021年第1期1-15,共15页Petroleum Science Bulletin

基　　金：中国石油天然气集团有限公司—中国石油大学(北京)战略合作科技专项(ZLZX2020-01)资助。

摘　　要：准噶尔盆地南部阜康凹陷东斜坡上二叠统梧桐沟组储层富含多种类型的沸石。沸石类矿物通常在碎屑岩、特别是火山碎屑岩中集中发育。沸石对油气储层的储集性能具有重要的影响,但其成因机制仍存在争议。本研究利用扫描电镜、电子探针和光学显微镜识别了梧桐沟组的主要4种沸石类型:浊沸石、方沸石,部分片沸石以及少量斜发沸石。浊沸石和方沸石在研究区梧桐沟组含量较高,分别占沸石总含量的60%和30%,片沸石则相对含量较少,斜发沸石含量最少。阜东斜坡梧桐沟组沸石的分布特征主要受沉积微相、物源、地层水性质等因素的影响。在水下分流河道、河口坝等储层物性发育较好的微相中,沸石含量越高;并且在靠近南部博格达山物源区的地区,有利于沸石的发育,沸石含量高。此外,在CaCl2型地层水环境下,沸石的含量(主要为浊沸石)明显高于其它地层水环境。在高沸石含量的情况下(大于5%),沸石的含量与孔隙度、渗透率呈负相关关系,表明沸石胶结物的溶蚀作用对储层的物性和储集性能具有明显的改善作用。目前主流观点认为准噶尔盆地二叠系的沸石是由火山物质蚀变并依次转化而来,近期的研究中,将准西北缘二叠系的沸石划分为高温成因和低温成因两种,高温成因是由凝灰物质蚀变转化而来,低温成因则是由孔隙水结晶形成。早期的浊沸石遭受酸性流体的溶蚀,后期孔隙水在溶蚀孔隙中富集结晶形成第二期沸石。不同于传统意义上"火山物质水化"和沸石之间相互转化,通过扫描电镜和能谱分析,阜东斜坡梧桐沟组的沸石产生与长石的转化密切相关,其中浊沸石和片沸石主要来自于斜长石在碱性条件下的钠长石化,而方沸石则可能来自于钾长石在碱性条件下的转化作用。Widely distributed zeolites were identified in the upper Permian Wutonggou Formation in the east slope of the Fukang sag of the southern Junggar Basin,NW China.Zeolites are usually found in clastic rocks,especially in pyroclastic rocks.Zeolite has an important influence on the reservoir properties of oil and gas reservoirs,however,the genetic mechanisms are still controversial.Four types of zeolites were identified by using scanning electron microscopy(SEM),electron microprobe analysis and optical microscopy.The content of laumontite and analcite are greater in the study area,accounting for 60% and 30% of total zeolite,while the content of heulandite is relatively lower,and clinoptilolite the lowest.The distribution characteristics of zeolites in the Wutonggou Formation are mainly affected by sedimentary microfacies,provenance and stratum water properties.There is more zeolite in the microfacies with better physical reservoir properties,such as subaqueous distributary channels and river mouth bars in a deltaic sedimentary environment.And in the area close to the southern Bogda mountain source area,this is beneficial to the formation of zeolites.Meanwhile,in the CaCl2 stratum water environment,the content of zeolites(mainly laumontite)is obviously higher than that in other stratum water environments.When the zeolite content is greater than 5%,the content of zeolite is negatively correlated with porosity and permeability,indicating that the dissolution of zeolite cement could significantly improve the physical properties and storage performance of the reservoir.It is generally accepted that Permian zeolites in the Junggar Basin are derived from volcanic material alteration.In a recent study,zeolites in the study area are subdivided using the two kinds of genetic mechanisms,high and low temperature.The high temperature genetic mechanism is related to the alteration of tuff material,while the low temperature genetic mechanism is considered as crystallization caused by pore water.In the early stage,zeolite was dissolv

关 键 词：准噶尔盆地 梧桐沟组 沸石 溶蚀 形成机制 

分 类 号：P618.13[天文地球—矿床学]