Loading...

Screening of the EOR Scenarios for Shaly Heavy Oil Reservoirs Using Five-Spot Glass Micromodel: an Experimental Study

Mohammadi, Saber | 2010

889 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 41016 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Masihi, Mohsen; Ghazanfari, Mohammad Hossein; Kharrat, Riyaz
  7. Abstract:
  8. Most of the heavy oil reservoirs contain discontinuous shaly structures which affect fluid flow through porous media as well as oil recovery efficiency during EOR processes. However, selecting the best EOR technique which maximizes the oil recovery remains a topic of debate in the literature. In addition the effect of shale geometrical characteristics including: spacing from wells, discontinuity, orientation, number of shale streaks, shale's spacing and length on oil recovery factor are not well understood. In this work experiments have been performed on one-quarter five-spot glass micromodels. These models have been developed by a new method using laser technology. Generally, this research involves two parts. In the first part, different EOR experiments, e.g. water, polymer, solvent and surfactant flooding, will be conducted on various models containing randomly distributed shaly structures which are initially saturated with heavy oil under several fixed flow rate conditions. Using a digital camera, the successive images of the injection processes into crude oil have been recorded on a computer. Image analysis technique will be applied and the oil recovery will be determined as a function of injected fluid pore volume. The best EOR scenario will be proposed. In the second part, the effects of shale geometrical characteristics on oil recovery factor have been investigated. Moreover, some pore-level visualization representing the role of connate water saturation during EOR processes have been illustrated using these experiments. Some experiments are repeated to examine the reproducibility and validation of the results. Finally, a part of the experimental data will be used for developing and validating a simulation model by available commercial simulators which later can be used for some sensitivity analysis. Results show that the presence of shale streaks causes reduction of oil recovery and early breakthrough of injected fluids. In addition, these flow barriers increase tortuosity of injected fluids and the severityof fingering at the displacement front. Displacement efficiency of EOR processes in shaly systems depends strongly on the shale distribution configuration through porous media. Oil recovery in the homogeneous model is relatively constant after breakthrough time. However, in shaly models oil recovery shows a significantly increasing trend after the breakthrough time. It was found that ultimate oil recovery by polymer (PA) flooding in shaly model is 23% more than water flooding, 6% more than condensate injection and 7.7% more than surfactant(SDS) flooding. Consequently, for the range of experiments performed here, PA with concentration of 700 ppm is proposed as the optimum EOR scenario in shaly models. The results of this work reveal the effect of shales on oil recovery efficiency in five-spot models, and can be helpful for successful mapping design of injection/production wells in EOR operations of shaly oil reservoirs.
  9. Keywords:
  10. Heavy Oil ; Enhanced Oil Recovery ; Experimental Method ; Five-Spot Micromodel ; Discontinuous Shaly Structure

 Digital Object List

  • محتواي پايان نامه
  •   view

 Bookmark

No TOC