Monitoring the effect of discontinuous shales on the surfactant flooding performance in heavy oil reservoirs using 2D glass micromodels

Mohammadi, S ; Sharif University of Technology

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  1. Type of Document: Article
  2. DOI: 10.1080/10916466.2010.531351
  3. Abstract:
  4. Although most heavy oil reservoirs contain discontinuous shaly structures, there is a lack of fundamental understanding how the shaly structures affect the oil recovery efficiency, especially during surfactant flooding to heavy oils. Here, an experimental study was conducted to examine the effect of discontinuous shales on performance of surfactant flooding by introducing heterogeneities to represent streaks of shale in five-spot glass micromodels. Results show that oil recovery in presence of shale streak is lower than in its absence. Based on the authors' observations, the presence of flow barriers causes premature breakthrough of injected fluids and also an unstable displacement front. As well, displacement efficiency of surfactant flooding is dependent strongly on the shale distribution configuration. Increasing shale content causes reduction of ultimate oil recovery and also severe fingering during water flooding while it compensates during surfactant flooding considerably. In shaly patterns, in the case of surfactant flooding, the oil recovery after breakthrough increases significantly, while it changes much less for the case of water flooding as well as flooding in homogeneous model. Oil recovery efficiency and breakthrough time improved with increasing surfactant concentration. However, beyond a specific limit of sodium dodecyl sulfate concentration, around 2000 ppm, incremental oil recovery becomes insignificant. Presence of connate water in surfactant flooding scheme can improve the recovery efficiency in shaly patterns. Results of this work can be helpful to investigate the optimal location of injection/production wells during enhanced oil recovery schemes in shaly reservoirs using five-spot micromodels
  5. Keywords:
  6. Oil recovery ; Crude oil ; Efficiency ; Enhanced recovery ; Floods ; Glass ; Heavy oil production ; Petroleum reservoirs ; Reservoirs (water) ; Shale ; Sodium dodecyl sulfate ; Surface active agents ; Connate waters ; Discontinuous shales ; Five-spot micromodel ; Heavy oil ; Surfactant floods ; Oil well flooding
  7. Source: Petroleum Science and Technology ; Vol. 32, issue. 12 , Apr , 2014 , p. 1404-1417 ; ISSN: 10916466
  8. URL: http://www.tandfonline.com/doi/abs/10.1080/10916466.2010.531351#