页岩水化微观孔隙结构变化定点观测实验  

Investigation of microscopic pore structure variations of shale due to hydration effects through SEM fixed-point observation experiments

作　　者：隋微波 田英英[3] 姚晨昊 SUI Weibo;TIAN Yingying;YAO Chenhao(State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;Key Laboratory of Petroleum Engineering of Ministry of Education,China University of Petroleum,Beijing 102249,China;College of Petroleum Engineering,China University of Petroleum,Beijing 102249,China)

机构地区：[1]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 [2]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [3]中国石油大学(北京)石油工程学院,北京102249

出　　处：《石油勘探与开发》2018年第5期894-901,共8页Petroleum Exploration and Development

基　　金：国家自然科学基金面上项目"应力敏感条件下的数字岩心微观渗流分析方法研究"(51474224);中国石油大学(北京)青年创新团队C计划(C201605)

摘　　要：基于4种不同类型页岩露头岩样的水化实验,应用场发射扫描电镜对实验样品水化前、后的微观孔隙变化进行定点观测与对比分析。研究表明高含量的蒙脱石及碳酸盐类矿物有助于水化作用形成溶蚀孔及矿物颗粒的松动和脱落;样品原有的矿物颗粒排列、胶结状况和微裂隙发育情况对水化后溶蚀孔的形成和矿物颗粒的脱落具有重要影响;水化作用未改变有机质孔隙结构,水化过程中产生的溶蚀孔起源于基质矿物粒间孔和矿物粒内孔,基质孔隙的溶蚀过程也会造成矿物颗粒的松动和脱落;矿物颗粒沿平行层理面压实条件下,垂直层理样品一般较平行层理样品产生的溶蚀孔密度更大、小孔径溶蚀孔占比更高;对于天然微裂缝不发育的页岩样品,水化过程中微裂缝的产生与发展可能与碳酸盐类矿物含量有关。This paper conducted the shale hydration experiments by using four different types of shale outcrop samples.The microscopic pore structure variations before and after hydration were recorded,compared and analyzed through Field Emission Scanned Electronic Microscope(FESEM)with fixed-point observation technique.The results showed that higher content of montmorillonite and carbonate minerals would contribute to the form of dissolution pores and looseness of mineral grains;some critical factors also include original alignment and cementation of mineral grains,and distribution of natural microfractures.Hydration doesn’t change the organic pore structure.Almost all dissolution pores originated from mineral intergranular and intragranular pores in matrix,and the dissolution of matrix pores also lead to mineral particles to loose and fall off.When the mineral grains are aligned and compacted along with the bedding-parallel planes,the density of dissolution pores and the number of dissolution pores of small size in bedding-vertical specimens are usually larger than that in bedding-parallel specimens.For the shale samples with few natural microfractures,carbonate minerals may contribute to the generation and propagation of microfractures during hydration.

关 键 词：页岩 水化作用 微观孔隙结构 矿物组分 定点观测 

分 类 号：TE243[石油与天然气工程—油气井工程]