화학공학소재연구정보센터
Journal of Canadian Petroleum Technology, Vol.48, No.8, 37-41, 2009
An Accelerated Method to Measure the Swelling Behaviour of Caprock (Shale) in Steam Stimulation Process
Shale formations are used to serve as hydraulic and thermal barriers in steam stimulated processes such as steam-assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS). They are potentially subjected to swelling and softening when they are exposed to fresh water. A conventional swell test on clay shale is very slow and it can take months or years. In this study, an accelerated swell test is proposed, which applies an electrical potential gradient through the specimen. The applied external electrical field accelerates the ionic flows and subsequently speeds up the swelling process. Experimental results of this study on reconstituted bentonite specimens saturated with sodium chloride solution have proved the proposed idea. Possible electrochemical reactions and their influence on the experimental set up have been discussed. A mathematical model based on coupling the flow equations in micro and macro levels has been developed to quantify this process.