Reservoir Evaluation and Development ›› 2020, Vol. 10 ›› Issue (3): 109-114.doi: 10.13809/j.cnki.cn32-1825/te.2020.03.017

• Comprehensive Research • Previous Articles     Next Articles

Study on mechanism and controlling factors of polymer flooding in conglomerate reservoir

WANG Zhiyuan1,ZHANG Liehui1,TAN Long2,ZHANG Chaoliang2,TANG Hongming1   

  1. 1. State Key Laboratory of Petroleum Reservoir Geology and Development Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. PetroChina Xinjiang Oilfield Company Exploration and Development Research Institute, Karamay, Xinjiang 834000, China
  • Received:2019-05-06 Online:2020-06-26 Published:2020-07-03

Abstract:

Taking the conglomerate reservoir of the Lower Karamay Formation in Qidong-1 area of Karamay Oilfield as the research object, the relation between physical properties, lithology and pore structure modes and the degree of recovery of polymer flooding is studied by laboratory experiments. And by means of nuclear magnetic resonance(NMR) technology, the experimental method of the study on the kinetics of polymer crude oil utilization is established and the kinetics of micro-porosity in the polymer flooding process of conglomerate reservoirs is analyzed. Through the micro-displacement experiments, the residuals after polymer flooding in conglomerate reservoirs are analyzed. The results show that the polymer flooding mainly displaces the cluster-like residual oil and the island-like residual oil. The polymer-driven residual oil accounts for the largest proportion of the total remaining oil. During the polymer flooding process, due to the complex pore structure of conglomerate and high viscosity of polymer solution, the large oil droplets are sheared into small oil droplets, and partially of which are dragged out of the pores by the polymer solution. The correlation between the degree of enhanced oil recovery by polymer flooding and core porosity and permeability is not obvious, however, it is related to the lithology and pore structure of the reservoir. The order of enhanced oil recovery with different lithologic polymer flooding from coarse to small is: boulder coarse sandstone>glutenite>unequal grain small conglomerate>fine conglomerate. There is a quadratic parabola relation between the degree of polymer recovery and dynamic oil saturation.

Key words: Karamay Oilfield, conglomerate reservoir, polymer flooding, flooding mechanism, oil recovery

CLC Number: 

  • TE341