A Simulation Study of Enhanced Oil Recovery Using Carbon Dioxide Foam in Heterogeneous Reservoirs
Open Access
- Author:
- Tham, Su Li
- Area of Honors:
- Petroleum and Natural Gas Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Dr. Russell Taylor Johns, Thesis Supervisor
Turgay Ertekin, Thesis Honors Advisor - Keywords:
- foam
enhanced oil recovery
foam enhanced oil recovery
surfactant alternating gas
water alternating gas
sag
wag
eor
fawag - Abstract:
- Conventional gas flooding suffers from poor sweep efficiency in heterogeneous reservoirs. In absence of mobility control, gas preferentially travels through the path of least resistance, bypassing oil in low permeability areas. Stable foams restrict flow in high permeability channels, diverting flow to the lower permeability layers. This allows injected fluid to contact oil which would have been unswept by conventional gas flood. The objective of this research is to determine the extent of improvement caused by use of foam for CO2 floods in a range of heterogeneous reservoirs. Moreover, this study aims to provide a qualitative understanding of foam in heterogeneous reservoirs which would help in designing successful CO2 foam flooding in enhanced oil recovery projects. The simulation study involves 2D reservoir models with varying reservoir heterogeneity modeled by different Dykstra-Parsons coefficients and correlation lengths in the areal and vertical directions. A Surfactant-Alternating-Gas (SAG) scheme and a Water-Alternating-Gas (WAG) scheme were carried out to determine the improvement of using foam in SAG compared to conventional WAG. The CO2 breakthrough times, recovery factors, and sweep efficiencies based on pore volume injected are calculated from simulation results. The study showed that all three factors were improved across all heterogeneities when foam was present in the system.