RU2239122C2 - Pump station for pumping multi-component gas containing mixture - Google Patents

Abstract

FIELD: oil industry.

SUBSTANCE: inlet of the screw pump is connected with the additional tank filled with oil-water mixture through a pipeline.

EFFECT: enhanced efficiency.

10 cl, 1 dwg

Description

The invention relates to pumping stations for pumping multicomponent gas-liquid mixtures, mainly oil well products.

A known method of pumping oil well products, including the separation of a multicomponent gas-containing mixture before entering the pumping station [Oilfield equipment. Directory. Ed. E.I. Bukhalenko. - M .: Nedra, 1990, p. 425].

The disadvantage of this method is the need for complete removal of gas from the liquid fraction during separation (the complexity of the process), as well as the loss of gas and negative environmental consequences when it is burned in a flare unit.

The use of multiphase pumping stations has several advantages: 1) a simplified and completely tight system for transporting well products from the production site to the central oil (gas) treatment point, regardless of its distance; 2) increasing the flow rate of the well (oil recovery) by reducing pressure at the wellhead. At the same time, submersible borehole pumps are operated in more favorable technological conditions; 3) reduction of harmful effects on the environment; 4) reduction of capital expenditures for the development of the field (abandonment of the construction of long oil collectors and a gas pipeline); 5) the ability to operate wells, as well as the field as a whole in economically profitable modes by automatically maintaining the pressure at the pump inlet; 6) inclusion in the general system of field development of zones or individual wells (clusters), geographically remote or located in remote places; 7) the possibility of 100% gas utilization starting from the first day of field operation.

There are various technical solutions for pumping a gas-liquid mixture: pumping units containing metering and booster piston pumps, interconnected by a pipeline and valve [a.s. USSR No. 1339297, class F 04 B 23/00, publ. 09/23/87; A.S. USSR No. 1585545, class F 04 B 23/00, publ. 08/15/90], pumping stations with preliminary separation of the production of oil wells in front of the station into oil, water and gas, followed by separate injection and mixing after the station [a.s. USSR No. 623049, class F 17 D 1/00, publ. 1978; A.S. USSR No. 653481, class F 17 D 1/00, publ. 1979, US Pat. RF №2007659, class F 17 D 1/00, publ. 1994].

The disadvantages of the known technical solutions are the design complexity, low reliability and high cost of pumping stations that implement these technical solutions.

The closest in technical essence and the achieved result is the selected as a prototype pump station for pumping multiphase mixtures containing a screw pump mounted on the pipeline [P.E. Amosov et al. Screw compressor machines. L .: Engineering, 1977, p. 13].

The well-known screw pump-based station is simple in design and operation, reliable in operation, and economical (efficiency up to 75%). However, at high gas contents (60 ... 100 vol.%) And large degrees of pressure increase (5 ... 10 times or more), its efficiency decreases to 20 ... 30% and an unacceptably high overheating of the screw pump occurs due to the lack of liquid sealing and cooling at the points of contact between the screws and the pump casing.

To eliminate these drawbacks, a gas-containing oil pumping station is proposed, comprising a screw pump mounted on a pipeline, in which, according to the invention, the screw pump inlet is connected by a line with an additional liquefaction tank filled with an oil-water mixture.

At the same time, an adjustable valve can be installed on the line, which can open when a gas plug or mixture with a high gas content enters the pump inlet, for example, made in the form of an electromagnetic valve electrically connected through a control unit to a thermocouple installed at the pump outlet.

In this case, the actuator of the adjustable valve can be made in the form of a bellows, the cavity of which is communicated by means of a capillary with a sealed chamber installed at the outlet of the pump pipeline filled with a liquid with a high coefficient of thermal volume expansion.

In this case, the liquefaction tank can be additionally connected to the pump outlet with the formation of a circulation circuit.

In this case, a refrigerator can be installed in the circulation circuit.

In this case, the liquefaction tank can be made in the form of a hydrostatic separator.

In this case, a centrifugal separator can be located in the upper part of the liquefaction tank.

In this case, the actuator of the adjustable valve can be kinematically connected with a float level gauge installed inside the liquefaction tank.

In this case, the valve can be installed inside the tank, and its actuator is connected by a rod with a float.

In this case, the liquefaction tank may contain two outlet pipes installed at different heights, one (upper) of which serves to exit the gas, and the other (lower) - for the liquid fraction.

In this case, the liquefaction tank can be made in the form of a slit flow meter.

A comparative analysis of the inventive pumping station with the prototype and with other solutions in the art shows that the set of features set forth in the patent formula is unknown from the existing level of technology, on the basis of which it can be concluded that it meets the criteria of the invention of "novelty."

According to the applicant and the authors, the totality of the essential features set forth in the patent formula does not follow explicitly from the prior art, as it does not show the effect on the technical result obtained - a new property of the object - the totality of the features of the patent formula, which allows us to conclude compliance of the proposed solution to the second criterion of "inventive step".

The compliance of the proposed solution with the criterion of the invention "industrial applicability" can be seen from the following example of a specific implementation of the pumping station.

The invention is illustrated in the drawing, which shows a functional diagram of a pump installation made with a circulation circuit and an electromagnetic valve controlled by a thermocouple signal installed at the pump output (dependent paragraphs 2, 4 of the patent formula).

Items shown in the diagram:

1 - pipeline;

2 - screw pump;

3 - liquefaction tank;

4 - oil-water mixture;

5 - circulation line;

6 - adjustable valve;

7 - an electromagnet;

8 - electronic control unit;

9 - thermocouple.

The pump installation includes a screw pump 2 installed on the pipeline 1, the outlet of which is connected to a liquefaction tank 3 filled with an oil-water mixture 4. The pump inlet 2 is connected to the tank 3 by a line 5 with the formation of a circulation circuit. An adjustable (electromagnetic) valve 6 is installed on the circulation line 5, the electromagnet 7 of which is electrically connected via an electronic control unit 8 to a thermocouple 9 located at the outlet of the pump 2.

The operation of the pumping station is as follows.

When the screw pump 2 is turned on, the gas-oil mixture is pumped through pipeline 1. At the pump outlet, the mixture enters the tank 3, in the lower part of which the oil-water fraction (mixture) accumulates 4. In the event of a gas plug or gas-oil mixture entering the pump inlet 2 with a high ( 60 ... 90 vol.%) The gas content heats the mixture due to adiabatic compression of the gas and a decrease in liquid cooling of the pump 2. This heating is detected by a thermocouple 9 at the outlet of the pump 2 and causes the electronic control unit 8 to operate cal control signal from which is fed to the solenoid valve 6. The valve 7 opens 6. From the tank 3, the oil-water mixture through the open solenoid valve 6 along the line 5 enters the inlet of the screw pump 2. This ensures the restoration of the efficiency of the pump and eliminates its overheating.

Using the claimed invention allows to reduce the energy consumption for pumping multicomponent oil and gas mixtures with screw pumping stations (almost to the level of energy consumption for separate transportation of the gas fraction), while maintaining the advantages of screw pumps (simplicity, the ability to pump mixtures with a gaseous fraction from 0 to 100%, high reliability, durability and ease of use). Distinctive features of the pumping station are low capital and operating costs.

Claims (11)

1. A pumping station for pumping a multicomponent gas-containing mixture containing at least one pump, for example a screw pump mounted on a pipeline, characterized in that the pump inlet is connected by a line with an additional liquefaction tank filled with oil-water mixture. 2. A pump station according to claim 1, characterized in that an adjustable valve is installed on the line, which is configured to open when a gas plug or mixture with a high gas content enters the pump inlet, for example, made in the form of an electromagnetic valve electrically connected through a control unit to a thermocouple installed at the pump outlet. 3. The pump station according to claim 2, characterized in that the variable valve actuator is made in the form of a bellows, the cavity of which is connected via a capillary to a sealed chamber installed at the outlet of the pump pipeline, filled with a liquid with a high coefficient of thermal volume expansion. 4. The pump station according to claim 1, characterized in that the liquefaction tank is additionally connected to the pump outlet with the formation of a circulation circuit. 5. The pump station according to claim 4, characterized in that a refrigerator is installed in the circulation circuit. 6. The pump station according to claim 4, characterized in that the liquefaction tank is made in the form of a hydrostatic separator. 7. The pump station according to claim 6, characterized in that in the upper part of the liquefaction tank is a centrifugal separator. 8. The pump station according to claim 6, characterized in that the variable valve actuator is kinematically connected to the float level gauge installed inside the liquefaction tank. 9. The pumping station of claim 8, characterized in that the valve is installed inside the tank, and its actuator is connected by a rod with a float. 10. The pumping station according to claim 6, characterized in that the liquefaction tank contains two outlet pipes installed at different heights, one (upper) of which serves to exit the gas, and the other (lower) for the liquid fraction. 11. The pump station of claim 10, characterized in that the liquefaction tank is made in the form of a slit flow meter.