Reservoir Evaluation and Development ›› 2022, Vol. 12 ›› Issue (5): 741-747.doi: 10.13809/j.cnki.cn32-1825/te.2022.05.005

• Methodological and Theory • Previous Articles     Next Articles

Prediction method of migration law and gas channeling time of CO2 flooding front: A case study of G89-1 Block in Shengli Oilfield

CUI Chuanzhi1(),YAN Dawei1,YAO Tongyu1,WANG Jian2,ZHANG Chuanbao2,WU Zhongwei1   

  1. 1. School of Petroleum Engineering, China University of Petroleum(East China), Qingdao, Shandong 266580, China
    2. Exploration and Development Research Institute, Sinopec Shengli Oilfield Branch, Dongying, Shandong 257015, China
  • Received:2021-12-28 Online:2022-10-26 Published:2022-09-27

Abstract:

CO2 gas channeling time prediction is of great significance for CO2 gas channeling prevention and enhanced oil recovery. Current studies rarely involve quantitative characterization of the gas channeling time. According to the parameters of the target block reservoir, the crude oil viscosity, reservoir permeability, gas injection rate and injection-production well spacing and other factors impact on the moving rule of the CO2 drive front is analyzed by the numerical simulation method, then the characterization formula of gas flow time and gas flow influence coefficient considering multiple factors is established, and the accuracy of the formula is verified by comparing with the field practice. The results show that under the condition of constant pressure production, the sweep efficiency decreases with the increase of crude oil viscosity. When the crude oil viscosity is greater than 3 mPa·s, the increase of gas emergence time slows down. When the reservoir permeability increases, the seepage resistance decreases, the displacement front moves faster, and the oil well breaks out earlier. When the gas injection velocity increases, the leading edge movement speed increases and the gas appearance time advances. When the gas injection velocity is 2 500 m3/d, the sweep efficiency is the minimum. When the injection-production well spacing increases, the moving speed of gas front slows down, and the gas emergence time of oil well prolongs. When the injection-production well spacing is larger than 250 m, the well spacing continues to increase, and the sweep efficiency increases slightly.

Key words: CO2 flooding, quantitative characterization of gas channeling time, leading edge migration, reservoir numerical simulation, sweep efficiency

CLC Number: 

  • TE3