- •Physical foundations of oil fields development and enhanced oil recovery methods
- •Introduction
- •1.2 Pool-reservoir properties.
- •1.3. Heterogeneity and anisotropy of reservoirs
- •2.1. Rock pressure and effective pressure.
- •2.2. Reservoir energy types.
- •2.3. The main sources of reservoir energy.
- •2.4. Operation modes of oil deposits.
- •2.5. Elastic-water drive
- •2.6. Dissolved gas drive
- •2.7. Gas cap drive.
- •2.8. Gravity drive
- •3.1. Productive formation.
- •3.2. The reservoir recovery and oil recovery factor (orf).
- •3.3. The well patterns - development systems of production facilities on natural recovery modes.
- •3.4. Enhanced recovery systems
- •3.5. Field development systems
- •3.5.1. Simultaneous production facilities development
- •3.5.2. Successive development systems.
- •3.6. Oil fields development parameters
- •3.6.1. Technological development parameters
- •3.6.2. Borehole grid. Wells’ density.
- •3.6.3. Krylov’s parameters. Compensation factor. Water cut factor.
- •3.6.4. Oil fields development rates.
- •3.6.5. Development stages of the production facilities (oil fields)
- •3.7. Types of water flooding
- •3.7.1. Edge water flooding.
- •3.7.2. Boundary water flooding
- •3.8. Circle water flooding.
- •3.8.1. Direct line drive systems. Their varieties – block systems.
- •3.8.2. Grid water flooding systems.
- •3.8.3. Selective and Spot water flooding.
- •3.8.4. Barrier water flooding system.
- •4.1. Porous formation models.
- •4.1.1. Deterministic model
- •4.1.2. Stochastic-statistical model.
- •4.2.4. Pollard model.
- •4.2.5. Models use peculiarities of the reservoirs of complex structure.
- •4.3. Water saturation and watering.
- •4.4. Reciprocating and non-reciprocating oil displacement.
- •4.4.1. Reciprocating displacement.
- •4.5. Displacement characteristics.
- •5.2. Project documentation.
- •5.3. Field-geologic characteristic of the deposit.
- •5.4. Rational development system.
- •6.1. Geological peculiarities reservoir structure with high-viscosity oil.
- •6.2. The deposit Russkoye
- •6.3. Katangli deposit.
- •6.4. Canada high-viscosity oil deposits.
- •6.5. The main peculiarities of high-viscosity oil deposits development.
- •7.1. Enhanced oil recovery methods classification.
- •7.2. Production stimulation methods (psm)
- •7.3. Enhanced oil recovery methods (eorm)
- •7.4. The forms of residual oil condition.
- •7.5 The reasons of residual oil condition.
- •7.6. The conditions of effective enhanced oil recovery methods use.
- •7.7. Oil deposits management and enhanced oil recovery methods.
- •8.1. Oil displacement by water solutions of surface-active reagents (sar)
- •8.2. Sar adsorption
- •8.3. Sar (surface-active reagent) composition.
- •8.4. Polymer oil displacement.
- •8.5. Micellar-polymer flooding method.
- •8.6. Conformance change or control (straightening the injectivity profile) (cc)
- •8.7. The choice of the areas and wells for injectability profile enhancement technologies implementation.
- •9.1. Filtration flows’ direction changing.
- •9.2. Forced fluid withdrawal (ffw)
- •9.3. Cyclic water flooding.
- •9.4. Combined non-stationary water flooding.
- •10.1. Oil displacement by carbon dioxide (co2).
- •10.2. Oil displacement by hydrocarbon gas
- •10.3. Water-alternated-gas cyclic injection.
- •11.1. Physical processes, happening during oil displacement by heat-transfer agents.
- •11.2. Oil displacement by hot water and steam.
- •11.3. The method of heat margins.
- •11.4. Combined technologies of enhanced oil recovery of high-viscosity oil deposits.
- •11.5. Thermal-polymer reservoir treatment (tpt)
- •11.6. Cyclic steam treatment of producing wells
- •Disp-lace-ment front
- •Ther-mal front
- •Combustion front
- •Disp-lace-ment front
- •Ther-mal front
- •Injection temperature
- •11.8. Thermal-gas method of treatment.
- •12.1. Formation hydraulic fracturing (fhf)
- •12.2. Well operation with horizontal end.
- •12.3. Acoustic methods.
- •Conclusion.
- •The list of symbols and abbreviations.
- •Content
- •Introduction 3
- •4.1. Porous formation models………………………………………………..38
- •4.1.1. Deterministic model……………………………………………………38
9.4. Combined non-stationary water flooding.
The observed technologies: changing of the filtration flows direction, cyclic water flooding, forced fluid withdrawal (FFW) are non-stationary physical processes. Pressure, pressure differential depend on time. The changing of filtration flows is sometimes confused with cyclic flooding because injection termination in some wells, putting into operation of the others happens in equal time intervals. Significant difference from the cyclic flooding is that the operation termination of one group of the injection wells and involvement of the others leads to the change of pressure differential in the direction and time.
And these changes happen in a particular area of the operational area, increase the sweep coefficient of the formation due to lenses drainage of the formation areas that are not developed. The application of cyclic flooding is based on the existence of hydrodynamic connection between the interlayers of different permeability. Oil recovery from the low-permeability reservoir, oil cross-flow in the second semi-cycle from the LP to the HP does not formally increase the sweep coefficient. But it gives an opportunity to involve low-permeability differences of the effective thickness of the developed interval in the development. Therefore, it provokes the increasing of the thickness sweep coefficient. With the time the quantity of the flowing oil from the LP to the HP decreases, and the sweep coefficient is also reduced.
The combined non-stationary flooding should include the use of the changing of the filtration flow direction technology if there is a hydrodynamic connection between the interlayers of different permeability, that is, the possibility of combined implementation of two technologies: changing of the filtration flow direction and cyclic flooding. In this case, the reservoir sweep coefficient increases as due to the increase of the drainage area, and due to the flow of oil from the low-permeability reservoirs. Because the fluid flow increases, the replacement of the pumping equipment by more productive, which is chosen in accordance with the increased wells’ productivity factor is necessary. But the ECP (electrical centrifugal pump) replacement with more supply in this case is not the method of FFW because the water cut is not close to critical, and production facility is the on the second or third stage of development.
Combined non-stationary water flooding is possible only in hydrodynamically-connected interlayers.
CHAPTER 10. GAS AND WATER-GAS ENHANCED OIL RECOVERY METHODS
10.1. Oil displacement by carbon dioxide (co2).
For oil displacement from the reservoir there can be used carbon dioxide CO2., which at the temperature of 300-310 K0 and pressure over 10MPa is mixed with oil. However, resins and asphaltenes contained in oil, poorly soluble in CO2 and can precipitate. The critical values of CO2 P=7,38MPa, T=305 K0. For full solubility of CO2 there should be increased the temperature and pressure above the critical values, for example P=300MPa, T=360K0 [3,20] .
The carbon dioxide is pumped into the injection wells in the gaseous or liquid state in the form of the bank, then water is pumped. Being dissolved in oil, carbon dioxide, reduces its viscosity, reduces surface tension on the oil-water boundary. It leads to the increase of oil volume and compressibility factor, accompanied by a rise of porous space saturation by hydrocarbons, which leads to the increased phase permeability by oil.
Another way of CO2 use is in the following. Water with dissolved carbon dioxide (carbonated water) is pumped into the reservoir. Because of the higher chemical "relationship" oil and CO2 in result of oil and carbonated water the molecules of CO2 diffuse, loosen film heavy oil on the surface of the rock grains, make these oil films mobile, which leads to the increase of oil production rate.
Among the considered technologies the CO2 bank displacement by the pushed water has the advantage since it allows you to extract more oil from the reservoir, because it is not reasonable to trust only the separation of heavy oil films from the rock grains, such films can be a very small proportion of the residual oil.
To use this method you should have enough cheap CO2 to ensure cost-effective production.