Profile improvement during CO_2 flooding in ultra-low permeability reservoirs

作     者：Zhao Fenglan Zhang Lei Hou Jirui Cao Shujun 

作者机构：Research Institute of Enhanced Oil Recovery China University of Petroleum Key Laboratory of Enhanced Oil RecoveryCNPC Key Laboratory of Petroleum EngineeringMinistry of Education 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2014年第11卷第2期

页      面：279-286页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：Financial support for this work from National Sciencetechnology Support Plan Projects (No. 2012BAC26B00) the Science Foundation of China University of Petroleum, Beijing (No.2462012KYJJ23) 

主　　题：Ethylenediamine organic amine profile improvement ultra-low permeability reservoirs,mitigation of gas channeling CO2 flooding 

摘      要：Gas flooding such as CO2 flooding may be effectively applied to ultra-low permeability reservoirs, but gas channeling is inevitable due to low viscosity and high mobility of gas and formation heterogeneity. In order to mitigate or prevent gas channeling, ethylenediamine is chosen for permeability profile control. The reaction mechanism of ethylenediamine with CO2, injection performance, swept volume, and enhanced oil recovery were systematically evaluated. The reaction product of ethylenediamine and CO2 was a white solid or a light yellow viscous liquid, which would mitigate or prevent gas channeling. Also, ethylenediamine could be easily injected into ultra-low permeability cores at high temperature with protective ethanol slugs. The core was swept by injection of 0.3 PV ethylenediamine. Oil displacement tests performed on heterogeneous models with closed fractures, oil recovery was significantly enhanced with injection of ethylenediamine. Experimental results showed that using ethylenediamine to plug high permeability layers would provide a new research idea for the gas injection in fractured, heterogeneous and ultra-low permeability reservoirs. This technology has the potential to be widely applied in oilfields.