Reservoir Evaluation and Development ›› 2020, Vol. 10 ›› Issue (3): 45-50.doi: 10.13809/j.cnki.cn32-1825/te.2020.03.007

• Methodological and Theory • Previous Articles     Next Articles

Establishment of the characteristic chart for CO2 near-miscible flooding of peripheral oilfields in Daqing

WANG Xin,LI Min   

  1. Exploration and Development Research Institute of Daqing Oilfield, CNPC, Daqing, Heilongjiang 163712, China
  • Received:2020-03-24 Online:2020-06-26 Published:2020-07-03

Abstract:

At present, the oil recovery in the CO2 oil displacement area of the peripheral oilfields in Daqing is mainly predicted by numerical simulation with no empirical formulas. In order to solve this problem, firstly, an heterogeneous ideal model of miscible, near-miscible and immiscible by CO2 flooding based on the basic physical properties and PVT parameters of the peripheral oil field in Daqing oilfield is established. Secondly, three kinds of characteristic curves of CO2 flooding are defined, including carbon content-accumulation of oil, type A and type B. The feature curve is used to predict the recovery rate in the model, and the calculation method of characteristic curve suitable for CO2 near-miscible flooding modes is optimized. On this basis, the carbon content and recovery degree chart suitable for S block is established, and compared with the actual performance of S block. A-type gas drive characteristic curve is selected for the further establishment of the CO2 near-miscible drive chart, and this improved chart is applied to predict the recovery rate of S block. The results show that the recovery rate predicted by the CO2 near-miscible flooding chart is close to that predicted by the field test of S block. This method can predict the recovery rate of CO2 flooding simply and quickly, and has guiding significance for the next development and evaluation of S block and similar blocks.

Key words: CO2 flooding, peripheral oilfields in Daqing, near-miscible flooding, characteristic curve, recovery rate prediction

CLC Number: 

  • TE357