Reservoir Evaluation and Development ›› 2020, Vol. 10 ›› Issue (3): 96-103.doi: 10.13809/j.cnki.cn32-1825/te.2020.03.015

• Comprehensive Research • Previous Articles     Next Articles

Technical index evaluation of transport ability of profile control and displacement agents

ZHANG Yunbao1,2,LU Xiangguo1,LIU Yigang2,LI Yanyue2,CAO Weijia1,BAO Wenbo1   

  1. 1. MOE Key Laboratory of EOR, Northeast Petroleum University, Daqing, Heilongjiang 163318, China;
    2. CNOOC (China) Co., Ltd., Tianjin Branch, Tianjin 300452, China
  • Received:2019-02-12 Online:2020-06-26 Published:2020-07-03

Abstract:

In recent years, the application scale of chemical flooding technology has been increased, but the results of some field tests are not ideal. There are many reasons for this situation, including the adaptability of profile control and displacement agent with reservoir pores. Aiming at the actual demand of field production and theory, the evaluation method and technical index of transport capacity of chemical profile control and flooding agent are studied. The results show that the transport capacity of profile control agent in porous media is a necessary condition for realizing the diversion of deep liquid flow. The transport capacity can be evaluated by the ratio of the pressure difference(β) between the front and the back of core at the end of injection of profile control agent. The recommended technical index ranges are as follows: ① β=1~3, good transport capacity; ② β =4~8, medium; ③ β=9~15, poor; ④ β>16, poor. The retention and transport ability of profile control and displacement agents are closely related to the molecular structure of materials, aggregate size and core permeability. Their purposes are contradictory and need to be taken into account reasonably in practical application. Viscosity is an index to evaluate the internal friction of fluids. The internal friction of polymer solution is related to polymer concentration, molecular aggregate morphology and salinity of solvent water. The size of polymer aggregates can be changed by intermolecular physical association and chemical cross-linking reaction, which can increase the friction force and viscosity of polymer solution, but this will also lead to poor transport capacity of polymer solution, and then weaken the deep retention and liquid flow diversion effect of polymer solution.

Key words: profile control and displacement agent, transport ability, technical index, physical simulation, mechanism analysis

CLC Number: 

  • TE357