Special Oil & Gas Reservoirs ›› 2024, Vol. 31 ›› Issue (3): 167-174.DOI: 10.3969/j.issn.1006-6535.2024.03.022

• Drilling & Production Engineering • Previous Articles    

Study on Electronegative High-efficiency Polymer Degrading Agent and Field Pilot Test

Wen Yuchen1, Hou Jirui1, Lou Zeyang2, Pan Yinuo1, Qu Ming3   

  1. 1. EOR Research Center (Beijing) China University of Petroleum, Beijing 102249, China;
    2. PetroChina Qinghai Oilfield Company, Haixi, Qinghai 816400, China;
    3. NEPU Sanya Offshore Oil & Gas Research Institute, Sanya, Hainan 572024, China
  • Received:2023-04-26 Revised:2024-03-20 Online:2024-06-25 Published:2024-07-26

Abstract: An electronagtive high-efficiency polymer degradation agent is developed in this study to address the problem of polymer plugging caused by long-term polymer injection during polymer flooding. In this study, the microscopic morphology, system stability, degradation performance, and viscosity reduction performance of the degradation agent were studied by means of electron microscopy, Zeta potentiometer, and multi-angle light scattering instrument, and the dynamic degradation effect of the degradation agent in porous media was evaluated. The results show that the optimal dosage of the degradation agent is 1% by mass fraction, both the viscosity reduction rate and degradation rate of the polymer can reach over 95% at this dosage. The degradation agent exhibits strong capacity of degradation for polymers and polymer clusters, with a significant effect on removing blockage. And on the other hand, the degradation agent is featured with low corrosiveness and causes little damage to wellbore and pipelines. A field test of plugging removal by polymer injection was conducted in Well W4-4 of the JZ9-3 Oilfield, and the field plugging removal effect of electronegative high-efficiency polymer degradation agent was verified. This polymer degradation agent can provide technical support for the efficient development of polymer flooding.

Key words: polymer flooding, polymer degradation agent, plugging, viscosity reduction rate, degradation rate, enhanced oil recovery

CLC Number: