Enhanced recovery methods
Course objectives: By taking the exam, the student will be able to apply the criteria for selecting the method of enhancing the reservoir performance and know the evaluation procedures, including the physical, technological and economic aspects of each method.
Course content:
- Changing the ratio of mobility, wettability or viscosity of fluid in a reservoir;
- Analysis of fields that are suitable candidates for a particular EOR method - analysis of the given reservoir and production parameters and screening by the Taber method;
- Criteria for selecting the supplementary extraction method (EOR);
- Review and analysis of activities and performance of world-famous EOR studies and projects;
- Chemical methods:
- Elements of the study of increasing the recovery by chemical methods - injection of surfactants, polymers, alkalis + infrastructure required for the application of supplementary methods;
- Case Study - Injection of polymers, analysis of prices of products (polymers) available on the market and the price of injection;
- Analysis, ie interpretation of laboratory analysis of rheological properties of different types of polymers (determination of the ratio of shear stress and viscosity of polymers);
- Analysis and selection of the optimal solution (ie concentration) of polymers - interpretation by modified Buckley - Leverett method, determination of "retardation factor", "oil banking";
- Matching of laboratory coreflood measurement data + polymer injection with the analytical model and confirmation by the simulation coreflood model;
- Case study: Analysis of polymer injectivity into the reservoir and the efficiency of flooding with the use of polymers, analytical and simulation models, the impact of heterogeneity;
- Thermal methods:
- Elements of the study of steam injection and cyclic steam injection (huff & puff) - thermal concepts (parameters), heat losses, well spacing, gravity drainage with the help of steam;
- Case study - Thermal EOR, consideration of high utilization of thermal energy of produced fluid and use of solar energy to help heat water;
- Balancing energy sources for hydrocarbon production by steam injection;
- Losses, ie ratios of heat losses during injection into wells of different configurations (different conductivities and temperatures of surrounding rocks, different well diameters, different injection speeds);
- Simulation of thermal efficiency by thermal simulator (Eclipse) - Steam assisted gravity drainage;
- Gas injection in miscible and immiscible conditions:
- Elements of the study of gas injection in miscible conditions - estimation of recovery based on measurement of minimum mixing pressures and slim-tube test of extraction;
- Case Study - CO2 EOR (required analyses, well tests, pilot, parameters for evaluating the success of CO2 EOR methods);
- PVT analysis of CO2 injection EOR - interpretation of swelling tests and principles of PVT simulation of CO2-oil system, triangular diagram.
- Compositional simulation of slimtube test, harmonization with laboratory data;
- Case sensitivity analysis of cost-effectiveness of different WAG ratios when CO2 is injected into the reservoir - analysis of technological parameters (injectivity, corrosion under different conditions, minimum fracture pressure);
- Analysis of CO2 retention in the reservoir based on a simulation model and possible benefits with a smaller recovery, but large retention;
- Microbiological methods of increasing recovery;
- Techno-economic conditions for the application of EOR methods;
- Features of simulation models for each EOR method;
- Criteria for the selection of formation and candidate wells for hydraulic fracturing;
- Reservoir engineering characteristics of unconventional reservoirs;
- Estimation of gas and gas condensate productivity from low-permeability reservoirs (influence of capillary forces on flow and non-Darcy flow in the near-wellbore zone);
- Case study: determination of the production regimes of reservoirs with low-permeability zones (eg blockage of gas flow due to condensate formation).
Learning outcomes at the level of the course:
- Explain the mechanisms of enhanced recovery methods;
- Select candidate fields to apply enhanced recovery methods to increase recovery;
- Make simulation models of injection of gases, steam, polymer solutions and surfactants;
- Compare the cost-effectiveness of different WAG ratios;
- Show the examples of chemical and thermal methods, as well as gas injection under miscible and non-miscible conditions;
- Describe the specifics of unconventional reservoirs;
- Compare and show the differences of the scenarios of primary, secondary and tertiary oil production;
- Evaluate the techno-economic perspective of the application of different strategies of increasing the recovery.