Special Oil & Gas Reservoirs ›› 2023, Vol. 30 ›› Issue (1): 107-113.DOI: 10.3969/j.issn.1006-6535.2023.01.015

• Reservoir Engineering • Previous Articles     Next Articles

Study and Application of Polymer Flooding for Enhanced Oil Recovery in Shallow Ordinary Heavy Oil Reservoirs

Wang Fengjiao1,2, Xu He1,2, Liu Yikun1,2, Wang Yongping3, Wu Chenyu4,5, Li Gaiyu1,2   

  1. 1. Northeast Petroleum University, Daqing, Heilongjiang 163318, China;
    2. Key Laboratory for Improving Oil and Gas Recovery (Northeast Petroleum University), Ministry of Education, Daqing, Heilongjiang 163318, China;
    3. China National Offshore Oil (China) Co., Ltd, Tianjin Company, Tianjin 300459, China;
    4. PetroChina Daqing Oilfield Co., Ltd., Daqing, Heilongjiang 163453, China;
    5. Heilongjiang Provincial Key Laboratory for Oil and Gas Reservoir Production and Injection Increase, Daqing, Heilongjiang 163453, China
  • Received:2022-03-22 Revised:2022-10-20 Online:2023-02-25 Published:2023-03-24

PDF (PC)

Abstract: Block J-XC is a common heavy oil reservoir with high porosity and permeability, shallow reservoir burial, and thin thickness. Due to high viscous resistance in the water flooding process, small effect range of water flooding, low reservoir productivity and low recovery rate by water flooding, it is necessary to change the development method and employ polymer flooding method to enhance the oil recovery. On the basis of polymer injectivity evaluation, the injection parameters and injection-production relationship of polymer flooding were optimized by core flow test and numerical simulation, including the mass concentration of polymer injection, injection volume, injection rate, well pattern, well spacing, injection-production ratio, so as to obtain the best injection parameters and injection-production relationship. The result shows that the injectivity and high utilization efficiency of the polymer were actualized under the conditions of 2 100×104 relative molecular mass of the polymer, 1 500 mg/L injection mass concentration and 0.400 times of pore volume; the optimal reservoir engineering parameters were a five-spot pattern, a reasonable injection-production well spacing of 150 m, an injection rate of 0.070 times the pore volume per year, and an injection ratio of 1.1 to 1.2 for different thicknesses of oil reservoirs according to their optimal single-well daily injection volumes. The pilot test in the field proves the significant effect of increasing oil and decreasing water cut in the target well cluster. As of June 2021, the cumulative injection rate of polymer is 0.228 times the pore volume, and the cumulative oil increase is 5.06×104t, the recovery factor is enhanced by 6.75 percentage points and the water cut is decreased by 15.8 percentage points. There is much for reference of the results to the optimization of polymer flooding parameters and reservoir engineering design in shallow ordinary heavy oil reservoirs.

Key words: ordinary heavy oil, shallow layer, polymer flooding, parameter optimization, enhanced oil recovery

CLC Number: