Reservoir pressure maintenance system. RU patent 2520119.

FIELD: oil and gas industry.

SUBSTANCE: reservoir pressure maintenance system includes pumps, water distribution devices with flow meters, flow controllers, water passages connecting water distribution devices to branch lines coming to injectors with different intake and grouped as per the water passages in compliance with an intake and water injection pressure. According to the invention the water passages with connected injectors with high or medium intake are coupled to the collector of the water distribution device through a spring-type flow controller with a calibrated inlet port at a movable element of the flow controller that closes output channels with potential maintenance of the required fluid flow. Branch lines of injectors with high intake connected with branch lines of injectors with medium intake are coupled to the same water passage and equipped additionally with the similar spring-type flow controllers with the calibrated inlet port that ensures required fluid flow for the respective well considering interaction with the flow controller installed at the respective water passage. At that the pump discharge line connecting it to the water distribution device is equipped with a pressure sensor while the pump is equipped with a variable frequency drive connected functionally to the pressure sensor.

EFFECT: potential optimisation of pressure in water passages, reduction of their rapture risk and material costs to maintain reservoir pressure.

1 tbl, 3 dwg

The offer applies to the oil industry, in particular to the system of water injection into the reservoir for oil displacement and maintain reservoir pressure.

A well-known system of reservoir pressure maintenance (see training manual Uwizeyimana Operation of the system for maintaining reservoir pressure at oil field development", Ufa: Publishing house of UGNTU, 2007.- S-183), including pumps pumping station, manifold valves with flow meters and regulating valves, water lines connecting the collector manifold valves as separate injection wells different pickup and injection wells, grouped by waterways in accordance with pickup and pressure water injection.

The disadvantage of the system is centralized principle of regulation of pumping regimes (pressure, flow rate) water conduits, which set the flow of water to flow in General, regulators of manifold valves pumping station.

Closest to the technical nature and achieve results for the proposed system is a system of reservoir pressure maintenance, described in method of preparation of water for injection into injection wells (RF patent №2239698, EV 43/20, publ. in bull. №31 dated 10.11.2004 year), including additional wellhead fittings for setting water injection into each injection well individually.

The disadvantage of this system is that individual modes of water injection into injection wells pump pumping station must support the system of pipelines of high pressure, necessary for water injection into the well with high wellhead pressure in the borehole will be pumped to the desired amount of water on the basis of filtration-capacitive characteristics opened its productive formation, as in the rest of injection wells pumping pressure on the mouth should limit by setting the mouth of the fittings. When working under high pressure increases the probability of impulses (accidental depressurization) water in areas with presence of hazards affecting material pipeline (chemical and electrochemical corrosion, mechanical load and so on). In addition, when you change the mode of the system water-related stop viscoplastic injection wells or separate conduits for realization on them of planned or emergency works without stopping the pump pumping station and the rest of injection wells this pumping station, require reconfiguration modes injection wells or water to prevent perekachki in them of excess water.

The technical objectives of the invention are to minimize excess water injection into injection wells during scheduled or emergency stops water injection in a separate injection wells or water pumping station, optimization (reduction) of pressure in the pipelines and, as consequence, reduction of privnesti waterways due to exploitation under high pressure and optimization of energy costs for water injection into injection wells system of reservoir pressure maintenance.

Technical problems are solved, we offer a system for maintaining reservoir pressure, including pumps, water distribution devices with flow meters, flow regulators, the pipes connecting the water distribution devices with branches going to injection wells various pick-up and grouped according to the conduits in accordance with pickup and pressure water injection.

What's new is that the pipes connected to vysokopilya and/or srednerazmernye injection wells, combined with the reservoir water distribution devices through the flow regulator spring type, with input calibrated orifice on a movable element of flow regulator, overlapping output channels with the ability to maintain the required flow rate, and offtake viscoplastic injection wells connected with branches srednerynochnyh injection wells to one pipeline, additionally equipped similar spring flow regulators with input calibrated orifice, which ensures the required flow rate for the corresponding well with regard to cooperation with the control valve is installed on the corresponding pipeline, with a flick line pump, connecting it with the water distribution device is equipped by the gauge pressure and the pump - frequency-controlled drive, functionally related to the pressure sensor.

Figure 1 flow diagram of the system for maintaining reservoir pressure in the General form, in figure 2 - scheme of pump pumping station with the use of variable frequency drive; figure 3 - dependence of the specific privnesti from pressure for high-pressure pipelines with pressure pumping from 10.0 to 17.0 MPa.

A system of reservoir pressure maintenance includes a pump 1 (figure 1) pumping station, connected discharge line 2 through the header 3 water distribution devices 4, water lines 5, 6, 7 and outlets 8, 9, 10, 11 with attached vysokopiaristye injection wells 12, 13, iskopaemie injection wells 14, 15 and srednerazmernye injection wells 16, 17, 18, grouped by injection pressure water injection in various combinations. In addition, water lines 5, 6, 7 flow meters equipped with 19, 20, 21, respectively, as part water distribution devices 4, and offtake 5, 6, 8, 9 - regulator spring type (for example, model "FS200" production company "Smith International Ink" (USA), model "WE-07" production firm "BAKER" (USA) etc.) with input calibrated orifice on a movable element of flow regulator 22, 23, 24, 25 (structural elements not shown in figure 1), with flow regulators 22, 23 installed on the water lines 5, 6, respectively, in the structure of water distribution devices 4, and regulators consumption 24, 25 installed on bends 8, 9, respectively, in the estuary zone viscoplastic injection wells, 12, 13. Additional discharge line 2 pumps 1 can be fitted with a pressure sensor 26 (figure 2)and pump 1 - frequency-controlled drive 27, functionally related to the pressure sensor 26.

A system of reservoir pressure maintenance works in the following way.

From the power supply (not shown in figure 1) water pump 1 (usually dynamic centrifugal type) served through the discharge line 2 in the collector 3 water distribution devices 4 (e.g. manifold valves, manifold, and so on) and then the system of conduits 5, 6, 7 and 8 branches, 9, 10, 11 pumped into injection wells 12, 13, 14, 15, 16, 17, 18. The flow of water to flow 5, 6, 7, connected to the collector 3 water distribution devices 4, control flow meters 19, 20, 21. Make a preliminary ranking of the water lines 5, 6, 7, connected to the collector 3 water distribution devices 4, by type of connected groups of injection wells or individual injection wells and distinguish the following types of water:

- water line 5 - I type that is connected vysokopilya injection wells 12, 13 and Sredneuralskaya injection well 18, with a range of values pickup connected to the water line 5 wells significant's mouth viscoplastic injection wells, 12, 13 may apply stolboushin devices;

- water line 6 - II type that is connected only srednerazmernye injection wells 16, 17 or only vysokopilya injection well (not shown in figure 1), with a range of values pickup connected to the water line 6 wells 16, 17 minor;

- water line 7 - III type that is connected iskopaemie injection wells 14, 15.

Ranking injection wells up carried out on the basis of commercial practices, for example:

- vysokopilya injection wells 12, 13 - pickup more than 150 m 3 /day when the actual wellhead pressure water injection;

- iskopaemie injection wells 14, 15 - with acceleration up to 25 m 3 /day inclusive in actual wellhead pressure water injection;

- srednerazmernye injection wells 16, 17, 18 - with pickup from 25 m 3 /day up to 150 m 3 /day inclusive in actual wellhead pressure water injection.

On the conduit type I (conduit 5 figure 1) establish the flow regulator 22 in the structure of water distribution devices 4. On taps 8, 9 in the estuary zone viscoplastic injection wells, 12, 13, respectively, can be installed flow regulators 24, 25, if the difference in pickup srednerynochnoj injection wells 18 and viscoplastic injection wells, 12, 13 significant (for example, more than 50 m 3 /day) to adjust the mode of water injection directly into vysokopilya injection wells 12, 13.

On the conduit type II (conduit 6 to 1, as an example, conditionally shown srednerazmernye wells 16, 17) establish the flow regulator 23 only as part of the water distribution devices 4.

On the conduit type III (conduit 7 figure 1) the flow regulator is not set.

As regulators of consumption, 22, 23, 24, 25 is used flow regulators spring type with input calibrated orifice on a movable element of the flow regulator is operating in automatic mode and ensuring the flow rate of the water conduit is not more than the value specified by setting the regulator 22, 23, 24 or 25. Configure the setting value of each regulator 22, 23, 24 or 25 is the selection replacement diaphragm with a calibrated hole in it. Removable aperture with a calibrated hole is installed in the piston inside the flow regulator (not shown in figure 1). Through the diaphragm with a calibrated orifice flow of water, determined by the cross sectional area of the hole. With the increase of pressure drop as a result of higher discharge pressure or decreasing reservoir pressure piston moves, compressing the spring (not shown in figure 1) and reducing the flow area of the out-flow regulator 22, 23, 24 or 25, and the stream of water is limited, and the rate remains unchanged. When you reduce the pressure on the regulator 22, 23, 24 or 25 due to the reduction of discharge pressure or increase reservoir pressure piston moves, clenched spring and increasing the flow area of the flow through the flow regulator, and the stream of water increases, the rate remains unchanged. Flow regulators 22, 23, 24, 25 work in cooperation with each other, as established in the uniform of a hydrodynamic system of conduits 5, 6, 7, laterals, 8, 9, 10, 11 and injection wells 12, 13, 14, 15, 16, 17, 18. The setting of the flow in the flow regulator 22 set on the amount of required expenses injection connected to the water line 5 through bends 8, 9 vysokopilya injection wells 12, 13 and sridharamurthy injection well 18 in accordance with monthly regime injection wells. The setting of the flow in the flow regulator 23 set on the amount of required expenses injection connected to the water line 5 sridharamurthy injection well 17 and connected through a drainage 10 sridharamurthy injection well 16 in accordance with monthly regime injection wells. Setpoint flow regulators of consumption 24, 25 set individually in accordance with monthly regime injection vysokopilya injection wells 12, 13, respectively. Placement of flow regulators 22, 23 in the structure of water distribution devices 4 allows to reduce pressure in the water lines 5, 6, respectively, because the regulator spring type represent the flow rates with adjustable bandwidth. Installation of flow regulators 22, 23 on the water lines 5, 6, respectively, in the structure of water distribution devices 4 allows to reduce pressure in these conduits to the amount necessary for the implementation of water injection in the connected injection wells 12 (connected through diversion 8), 13 (connected through a drainage 9), 16 (connected through a drainage 10), 17, 18, the pressure in the pipeline 7 will be high for the implementation of water injection into connected iskopaemie 14 injection wells (connected to the water line 7 through tap 11), 15.

If disabling any of injection wells connected to the water lines 5, 6, 7, including through the bends 8, 9, 10, 11, to consider pumping station, there is a reduction of the total flow rate of water in the system water pumping station, change the operating mode of pump 1 and there is a redistribution of flows of injected water in vysokopilya injection wells 12, 13, srednerazmernye injection wells 16, 17, 18 and iskopaemie injection wells 14, 15, in some cases less, in others in a greater, as shown below.

For example, you stop pumping water in sridharamurthy injection well 16 (for the conduct of geological-technological emergency operations or in accordance with a monthly regime injection) water flow pumped via the pipeline 6, will decrease approximately on the size pickup srednerynochnoj injection wells 16. The consumption of water pumped via the pipeline 5, limited flow regulator 22 and will not change, but the flow of water injected into sridharamurthy injection well 17 and pumped via the pipeline 7 with attached iskopaemie injection wells 15 and through the diversion 11 iskopaemie 14 injection wells will increase slightly due to minor same growth of pressure in the discharge line 2 pumps 1 pumping station, the collector 3 water distribution devices 4 and conduit 5, the pressure in the water lines 6, 7 is not increased, since it is limited mounted regulator 22 and 23 respectively.

When the work is temporarily disabled srednerynochnoj injection wells 16 system of reservoir pressure maintenance is returned in original condition with parameters of job of the pump 1 and regime downloads in vysokopiaristye injection wells, 12, 13, Sredneuralsky injection wells 16, 17, 18 and iskopaemie injection wells 14, 15 in accordance with monthly regime injection.

Stop pumping in vysokopilya injection wells 12 and/or 13 or stop completely separate conduits 5, 6 or 7 can cause significant change of a mode of pump operation 1 pumping station with access it from the working zone, while significantly reduced the flow rate of the water pump 1 with increase of pressure in the discharge line 2 and the costs of pumping in iskopaemie injection wells 14, 15 will increase, which will lead to injection into the data injection wells of water in excess of the monthly regime of water injection. For adjustment of the pump mode 1 with a significant reduction of the flow rate of water flow line 2 pumps 1 will be equipped with a pressure sensor 26 (figure 2)and the pump drive 1 - frequency-controlled drive 27, functionally related to the pressure sensor 26 (similar to the diagram in the way of managing the system for maintaining reservoir pressure and the device for its implementation, RF patent №2278248, EV 43/20, publ. in bull. №17, 20.06.2006). If the pressure in the discharge line 2 pumps 1 above setpoint embedded in the controller VFD 27, lowering the speed of the shaft pump 1 and decrease of pressure in the discharge line 2 to level the set point, and the flow rate of water is reduced and remains in the new working area for reduced the number of revolutions of a shaft of the pump is 1, and the volume of water pumped in excess of the monthly injection regime of water, will be negligible or completely iskljucite, with pressure conduits 5 (1), 6, 7 when changing the mode of pump operation 1 pumping station will not change due to regulation of pressure in the discharge line 2.

When the work is temporarily disabled viscoplastic injection wells 12 and/or 13 or separate conduits 5, 6 or 7 the system of reservoir pressure maintenance is also returned in original condition with parameters of job of the pump 1 and regime downloads in vysokopiaristye injection wells, 12, 13, Sredneuralsky injection wells 16, 17, 18 and iskopaemie injection wells 14, 15 in accordance with monthly regime injection.

Thus, the use of the proposed system of reservoir pressure maintenance allows water injection into injection well 12-18 different pickup with a pump 1 pumping station and to minimize unnecessary non-productive water injection into injection wells 12-18 during pause part of injection wells or water pipes, connected to the pumping station, without additional manual adjustment of modes of their work, to optimize the pressure in the pipelines and, as consequence, to reduce privnesti water by eliminating their operation under high pressure, and thus to optimize the energy consumption for water injection into injection wells systems reservoir pressure maintenance.

A specific example.

Pump 1 (figure 1) pumping station of the Central nervous system 40-1400 have pumped water through water distribution unit 4 in vysokopreosv injection well 12 consumption 288 m 3 /day at the wellhead pressure of 8.5 MPa (this value is configured setting of the flow regulator 24 on the allotment 8), vysokopreosv injection well 13 with the consumption of 240 m3 /day at the wellhead pressure 8,0 MPa (this value is configured setting of the flow regulator 25 on the allotment 9) and sridharamurthy injection well 18 with the consumption of 144 m 3 /day when wellhead pressure 11,0 MPa (cumulatively on the conduit 5 consumption injection is 672 m 3 /day, this value is configured setting of the flow regulator 22), in sridharamurthy injection well 16 with the consumption of 144 m 3 /day at the wellhead pressure of 11.5 MPa and in sridharamurthy injection well 17 with the consumption of 146 m 3 /day at the wellhead pressure 11,0 MPa (cumulatively on the conduit 6 consumption, injection of 290 m 3 /day, this value is configured setting of the flow regulator 23), in iskopaemie injection well 14 with the consumption of 22 m 3 /day when wellhead pressure of 13.5 MPa and in iskopaemie injection well with a flow rate of 15 19 m 3 /day at the wellhead pressure of 13.5 MPa (cumulatively on the conduit 7 consumption injection is 41 m 3 /day). As regulators of consumption, 22, 23, 24, 25 is used, for example, flow regulators spring-type - model "FS200" production company "Smith International Ink" (USA). The total water consumption in, pump pump 1 in the water lines 5, 6, 7 through water distribution unit 4 is 1003 m 3 /day, while the consumption pressure in the discharge line 2 is 14.5 MPa if the speed of the pump shaft 1 3000 rpm For the installed pump CNS 40-1400 working area for consumption is from 672 m 3 /day (left boundary of the working area) up to 1152 m 3 /day (the right edge of the work area at the rated consumption 960 m 3 /day, the mode of operation of the pump with a flow rate 1003 m 3 /day at a pressure of 14.5 MPa is within the work area.

While stopping vysokopiaristye injection wells 13 and srednerynochnoj injection wells 18, for example, to conduct geological and technical measures at open water lines 6, 7, 8 branches, 10, 11 and open vysokopiaristye injection wells 12 on the allotment 8, there is a decrease in the total consumption of injected water through water distribution unit 4 to 629 m 3 /day while increasing the pressure in the discharge line 2 to 15.5 MPa, while there is a partial redistribution of injected water through water distribution the device is 4, namely: the conduit 6 consumption is not affected since it is limited by the regulator 23, conduit 5 consumption is reduced to 288 m 3 /day, as it remains open only vysokopilya injection well 12, connected to the water line 5 tap 8, flow injection to which is limited flow regulator 24, and the conduit 7, this rises to 50 m 3 /day, as the increase of pressure in the pipeline 7 increases pickup iskopaemie injection wells 14 to 26 m 3 /day at the wellhead pressure of 14.7 MPa and iskopaemie injection wells 15 to 24 m3 /day at the wellhead pressure of 14.7 MPa, i.e. there is a partial, or 22%, exceeding the mode of water injection in iskopaemie injection wells 14, 15. In addition, the reduced consumption of the pump to 629 m 3 /day beyond the left border of the working area of the pump 1. For this case effectively the application of the scheme of the system for maintaining reservoir pressure with a frequency-controlled drive 27 (figure 2) pump 1, functionally associated with the pressure sensor 26, installed in the discharge line 2 pumps 1. Disabling vysokopiaristye injection wells 13 (1) and srednerynochnoj injection wells 18 reduced consumption of injected water through water distribution unit 4 and begins to rise, the pressure in the discharge line 2 pumps 1, which is controlled by the pressure sensor 26 (2), above setpoint 14,5 MPa embedded in the controller VFD 27, which is functionally connected with pressure sensor 26, the controller instructs the frequency-controlled drive 27 to reduce the speed of the pump shaft 1 (figure 1) until about 1850 rpm Is a decrease in pressure in flow-line 2 to level setpoint 14.5 MPa, with the flow rate of water is reduced and remains in the new working area for reduced the number of revolutions of a shaft of the pump is 1, and the volume of water pumped in excess of the monthly injection regime of water, depending on the accuracy of the adjustment variable frequency drive 27 minimized up to its complete exclusion, i.e. the consumption of water by water pipeline 5 will be 288 m 3 /day (when disabled vysokopiaristye injection wells 13 and srednerynochnoj well 18), conduits 6 and 7 will cost the original 290 m 3 /day and 41 m 3 /day, respectively. The total flow pumped water through a water distribution unit 4 will be 619 m 3 /day, with excessive injection iskopaemie injection wells 14 and 15 are missing, because the pressure in the pipeline 7 not upgraded.

Changing flows and pressures on water conduits and injection wells in the table.

Working parameters

Initial state

Turned off the water line 6

Disabled well 13, 18 (no VFD)

Disabled well 13, 18 (a system with frequency-controlled drive)

Consumption, m 3 /day

Pressure, MPa

Consumption, m 3 /day

Pressure, MPa

Consumption, m 3 /day

Pressure, MPa

Consumption, m 3 /day

Pressure, MPa

Collector 3

Water line 7

The conduit 6(after the regulator 23)

The conduit 5 (after the regulator 22)

Well 13 (after flow regulator 25)

Well 12 (after a flow control 24)

Technical and economic efficiency of the proposed system for maintaining reservoir pressure is achieved by minimizing redundant non-productive water injection into injection wells during scheduled or emergency stops water injection in a separate injection wells or water pumping station with the use of minimally necessary number of regulators and optimal accomodation in conduits and mouth viscoplastic injection wells at insignificant cost of installation of flow regulators.

The use of this proposal allows for a small additional capital cost using the existing system of reservoir pressure maintenance to optimize the pressure in the pipelines and, as consequence, to reduce privnesti conduits through the installation part of the regulator in the structure of water distribution devices, and thus reduce the pressure in the water, on which they are installed to optimize the energy consumption for water injection into injection wells system of reservoir pressure maintenance through the use of variable-frequency drives of pump and, as a result, to reduce material costs maintaining reservoir pressure.

A system of reservoir pressure maintenance, including pumps, water distribution devices with flow meters, flow regulators, the pipes connecting the water distribution devices with branches going to injection wells various pick-up and grouped according to the conduits in accordance with pickup and pressure water injection, wherein the pipes connected to vysokopilya and/or srednerazmernye injection wells, combined with the reservoir water distribution devices through the flow regulator spring type with input the orifice on a movable element of flow regulator, overlapping output channels with the ability to maintain the required flow rate, and offtake viscoplastic injection wells connected with branches srednerynochnyh injection wells to one pipeline, additionally equipped similar spring flow regulators with input calibrated orifice, which ensures the required flow rate for the corresponding well with regard to cooperation with the control valve is installed on the corresponding pipeline, with a flick line pump, connecting it with the water distribution device is equipped by the gauge pressure and the pump - frequency-controlled drive, functionally related to the pressure sensor.