- •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
2.6. Dissolved gas drive
This mode (drive) is caused by the manifestation of elastic energy of dissolved gas in the oil expansion. When the pressure is below the saturation pressure, gas starts to separate from the oil. It leads to the formation of carbonated liquids and occurrence in the formation of two-phase filtration – gas+oil.
Gas volume Vг dissolved in oil volume Vн is determined by the Henry law.
Vг = р Sp Vн .
Where Sp - gas solubility factor in oil.
A part of the gas bubbles accumulates in the vault and forms the secondary gas cap. If Рпл=Рн, this drive is implemented in two phases. The first phase considers that the wells’ depression cones are expanded and merged (Fig.2.2). The second phase leads to the total pressure drop in deposits. High rate of pressure drop, the increase of gas factor are typical for the dissolved gas drive.
2.7. Gas cap drive.
Gas cap drive is realized because of manifestation of compressed gas expansion in the gas cap and is only possible with the advanced development of oil formation part of the oil and gas deposit. The pressure in the oil formation part falls. Due to the pressure difference (depression) in the gas cap and oil zone there is oil displacement from the reservoir by gas, invading from the gas cap. Gas pressure in the gas cap is reduced.
During elastic gas cap drive with some pressure decrease on the GOC (gas and oil contact) due to oil extraction, the expansion of gas in the gas cap starts. During hard gas cap drive at oil extraction, pressure in the gas cap is considered permanent. It is possible if there is big gas volume in the gas cap. The change of initial position of the GOC is called coning. Depressions and production rates are low at the gas cap drive; gas breakthrough to the perforation intervals of oil wells sharply increases gas factor.
2.8. Gravity drive
Gravity drive starts to be shown when other forms of energy are depleted, and is valid only oil potential energy (gravitational forces).
There are distinguished: 1). Gravity drive with moving oil pool outline - pressure-gravity. Oil under gravity pressure moves down the interlayer. Production rates are low, but constant.
2). Gravity drive with fixed oil pool outline (with a free surface), when the oil level is below the upper boundary of the horizontally bedded formation. Wells’ production rates are less than in the previous drive and eventually decrease.
2.9. Combined drives.
When there are different types of energy, there are several drives in the reservoir that act simultaneously. For example, it happens during the development of oil part of oil and gas deposit, underlain by active bottom water. Here are gas cap and elastic water drives working. The pressure at the bottom of the production well is less than the pressure in the gas cap and saturated thickness of the reservoir. Thus, the zones of collaborative filtration are formed in the reservoir: oil - gas, oil - water. The initial position of GOC and WOC is changed. Water and gas break through the holes of perforations of producing wells. There are two cones: gas from the top, water from the bottom. The output is gas and water out [2].
CHAPTER 3. SYSTEMS AND INDICATORS OF OIL FIELDS DEVELOPMENT.