摘要：Carbon capture, utilization, and storage, one proposed method of reducing anthropogenic emissions of CO2, relies on low permeability formations, such as shales, above injection formations to prevent upward migration of the injected CO2. Porosity in caprocks evaluated for sealing capacity before injection can be altered by geochemical reactions induced by dissolution of injected CO2 into pore fluids, impacting long-term sealing capacity. Therefore, long-term performance of CO2 sequestration sites may be dependent on both initial distribution and connectivity of pores in caprocks, and on changes induced by geochemical reaction after injection of CO2, which are currently poorly understood. This article presents results from an experimental study of changes to caprock porosity and pore network geometry in two caprock formations under conditions relevant to CO2 sequestration. Pore connectivity and total porosity increased in the Gothic Shale; while total porosity increased but pore connectivity decreased in the Marine Tuscaloosa. Gothic Shale is a carbonate mudstone that contains volumetrically more carbonate minerals than Marine Tuscaloosa. Carbonate minerals dissolved to a greater extent than silicate minerals in Gothic Shale under high CO2 conditions, leading to increased porosity at length scales approximate to 1m. Mineral reactions also contributed to a decrease in pore connectivity, possibly as a result of precipitation in pore throats or hydration of the high percentage of clays. This study highlights the role that mineralogy of the caprock can play in geochemical response to CO2 injection and resulting changes in sealing capacity in long-term CO2 storage projects.

关键字：caprock carbon sequestration Gothic Shale Marine Tuscaloosa nitrogen gas adsorption porosity

ISSN号：1092-8758

卷、期、页：卷: 33 期: 10 页: 725-735 特刊: SI

发表日期：2016-10-01

期刊分区（SCI为中科院分区）：四区

收录情况：SCI（科学引文索引印刷版）,ESI（基本科学指标数据库）,EI（工程索引）,SCIE（科学引文索引网络版）

发表期刊名称：ENVIRONMENTAL ENGINEERING SCIENCE

参与作者：Mouzakis, Katherine M.,Navarre-Sitchler, Alexis K.,Rother, Gernot,Banuelos, Jose Leobardo,Kaszuba, John P.,Heath, Jason E.,Miller, Quin R. S.,Alvarado, Vladimir,McCray, John E.

第一作者：王秀宇

论文类型：期刊论文

论文概要：Mouzakis, Katherine M.,Navarre-Sitchler, Alexis K.,Rother, Gernot,Banuelos, Jose Leobardo,王秀宇,Kaszuba, John P.,Heath, Jason E.,Miller, Quin R. S.,Alvarado, Vladimir,McCray, John E.，Experimental Study of Porosity Changes in Shale Caprocks Exposed to CO2-Saturated Brines I: Evolution of Mineralogy, Pore Connectivity, Pore Size Distribution, and Surface Area，ENVIRONMENTAL ENGINEERING SCIENCE，2016，卷: 33 期: 10 页: 725-735 特刊: SI

论文题目：Experimental Study of Porosity Changes in Shale Caprocks Exposed to CO2-Saturated Brines I: Evolution of Mineralogy, Pore Connectivity, Pore Size Distribution, and Surface Area