Reservoir Evaluation and Development ›› 2021, Vol. 11 ›› Issue (2): 241-247.doi: 10.13809/j.cnki.cn32-1825/te.2021.02.015

• Comprehensive Research • Previous Articles     Next Articles

Experiment on steam flooding assisted by gas injection in Z32 heavy oil reservoir in Fengcheng of Xinjiang and its application

SANG Linxiang1(),LYU Bailin1,LU Yingbo1,WANG Junheng2(),WANG Jian2,HUANG Kechuan2,MA Peng1,XING Xiangrong1   

  1. 1. PetroChina Xinjiang Oilfield Company, Karamay, Xinjiang 834000, China
    2. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2019-10-24 Online:2021-04-26 Published:2021-04-30
  • Contact: WANG Junheng E-mail:slx_zy@petrochina.com.cn;1187395805@qq.com

Abstract:

In the later stage of heavy oil reservoir development by steam injection, the steam channeling is serious and the development effect gets worse year by year. So it is urgent to apply relevant technologies to improve steam flooding performance. According to the characteristics of the heavy oil reservoir in Z32 Qigu Formation in Fengcheng Oilfield, the feasibility of steam flooding assisted by CO2 injection to improve the development effect has been studied. In the process of steam injection in heavy oil reservoir, the injection of CO2, N2 or flue gas can make crude oil swell, increase formation elastic energy, reduce viscosity of crude oil and improve oil flow capacity of crude. The swell and viscosity reduction effects of different types of injected gas on heavy oil have been measured by high temperature and high pressure crude oil sampler and core flow experiment device. The volume expansion of crude oil is about 10 % ~ 40 %, 2 % ~ 10 % and 4 % ~ 16 % by injecting CO2, N2 and simulated flue gas respectively, the viscosity is reduced by 27.3 % ~ 82.9 %, 4.3 % ~ 18.5 % and 10.2 % ~ 45.8 %, respectively, and the oil recovery is enhanced by 5.83 %, 3.08 % and 3.75 %, respectively. Therefore, CO2 is recommended as the injection medium. Field application shows that after the new technology is implemented, the daily oil production of the well group increases from 26.6 t to 36.2 t, the oil steam ratio increases from 0.174 to 0.206, and the total oil production increases by 1 158 t. Remarkable economic benefits are obtained, which provides references for the scale application of this new technology.

Key words: heavy oil, CO2, auxiliary steam drive, laboratory experiment, on-site application

CLC Number: 

  • TE345