Reservoir Evaluation and Development ›› 2022, Vol. 12 ›› Issue (5): 764-776.doi: 10.13809/j.cnki.cn32-1825/te.2022.05.008

• Methodological and Theory • Previous Articles     Next Articles

Laboratory experiment of front migration and gas channeling of CO2 immiscible flooding

KONG Weijun1(),CUI Chuanzhi2(),WU Zhongwei2,LI Lifeng1,SU Shuzhen1,ZHANG Jianning1   

  1. 1. No. 1 Oil Production Plant of Sinopec Jiangsu Oilfield Company, Yangzhou, Jiangsu 225265, China
    2. MOE Key Laboratory of Unconventional Oil & Gas Development, China University of Petroleum(East China), Qingdao, Shandong 266580, China
  • Received:2021-12-15 Online:2022-10-26 Published:2022-09-27
  • Contact: CUI Chuanzhi E-mail:kongwj.jsyt@sinopec.com;ccz2008@126.com

Abstract:

Currently, there are few works on the laws of front migration and gas channeling with laboratory experiments from the aspect of CO2 sweep efficiency. Therefore, a visual physical simulation device is used to carry out the physical simulation experiment of CO2 immiscible flooding of slab core. The influences of factors such as crude oil viscosity, reservoir permeability, reservoir heterogeneity and injection rate on the migration of CO2 immiscible flooding front and gas channeling laws are analyzed. The study found that under the conditions of constant flow injection in injection wells and constant pressure production in production wells, the viscosity of crude oil decreases, the permeability decreases, the reservoir is homogeneous, and the injection speed increases, which will lead to an increase in the recovery degree of CO2 immiscible flooding. Meanwhile, the decrease in the viscosity of crude oil, the lower the permeability, and the increase in the injection rate, also lead to the enhancement of the ability of the oil well to continue to expand sweep factor after gas breakthrough, that is, it can alleviate gas channeling. It is concluded that under the condition of constant flow injection in injection wells and constant pressure production in production wells, high injection rate development can alleviate gas channeling and obtain better development results. When the injection rate increased from 0.1 mL/min to 2 mL/min, the recovery increased from 15.4 % to 35.3 %, and the sweep factor difference increased from 8.3 % to 26.2 %. This research is of great significance for CO2 immiscible flooding gas channeling suppression and enhanced oil recovery.

Key words: CO2 immiscible flooding, front migration, gas channeling, sweep characteristics, laboratory experiment

CLC Number: 

  • TE348