RU203404U1 - Submersible plant with a vane pump and a gas separator for the production of formation fluid with a high content of gas and mechanical impurities - Google Patents

Abstract

The utility model relates to the oil industry and can be used in submersible installations with a vane pump and a gas separator for the production of formation fluid with a high content of gas and solids. The technical result of the utility model is to increase the reliability and efficiency of the installation with a gas separator and a vane pump. vane pump, gas separator, electric motor. Each stage of the pump contains an impeller and a guide vane. Between the driving disc of the impeller and the lower disc of the guide vane, an area is formed that is closed on the inner side. The gas separator contains a housing, a protective sleeve installed in the housing, a base with holes, a screw, an axial wheel, a head with channels for the passage of the separated liquid into the pump and holes for gas outlet into the annulus. A separating sleeve is installed between the auger and the axle wheel, which includes a confuser and a diffuser section. The separating sleeve is installed in a protective sleeve and consists of two parts: confuser and diffuser sections. On the confuser section of the separating sleeve, blades are made, the angle of inclination of which increases from inlet to outlet, the inner diameter of the separating sleeve is at least 12% less than the inner diameter of the protective sleeve, the angle of the blades at the exit from the axle wheel is at least 20% higher than at the outlet of the auger. The impellers and guide vanes of the pump are made using sand casting technology, the difference between the diameters of the driving and lower disks of the impeller and the guide vanes does not exceed 5%.

Description

The utility model relates to the oil industry and can be used in submersible installations with a vane pump and a gas separator for the production of formation fluid with a high content of gas and mechanical impurities.

Known from patent RU 72228, a borehole electric centrifugal pump unit for oil production, which includes a multistage submersible centrifugal pump and a gas separator, while the impellers and / or guide vanes of the pump stages and / or the screw and / or other parts of the gas separator are made of special alloys.

However, the design of the pump does not ensure that the flow is dispersed along the entire length of the flow path.

Also known from patent RU 2442023 is an electric centrifugal pump with a gas separator, in which screws with different strokes are used for feed ranges.

However, in the design of the gas separator, variable-stroke screws are used. The pressure in the separation chamber cannot be high enough, since the rotating ring of the partially degassed liquid in the separation chamber rests on an auger that pumps the gas-liquid mixture (GLC). Reverse currents appear, which reduce the pressure and disperse, crush the diameter of the gas bubbles. To reduce the harmful effect of gas on the energy parameters of the pump: head and efficiency, the design of the pump must be changed.

Known from the patent RU 2616331 gas separator of the installation of an electric centrifugal pump. For it, before placing the installation of the electric centrifugal pump in the well, the range of gas-liquid mixture feeds is determined, the inlet outer diameter of the gas separator screw and the inner diameter of the screw sleeve are calculated for each value of the range. Then the installation is completed with a batch of calculated screws and sleeves for each feed value within one well dimension. All sleeves and screws are made from the same blanks - one type of sleeve blank and one type of screw casting.

However, in this design, there is no separation of the flow part of the gas separator into inlet and separation areas, therefore, the pressure in the separation chamber cannot be high enough. Reverse currents appear, which reduce the pressure and disperse, crush the diameter of the gas bubbles. To reduce the harmful effect of gas on the energy parameters of the pump: head and efficiency, the design of the pump must be changed.

Known from patent RU 2193653 a gas separator containing a housing in which there are inlets for supplying a gas-liquid mixture, outlets for removing separated gas and an outlet channel for transferring degassed liquid to the pump working stages, a shaft installed in the housing. The screw diameter is less than the diameter of the separation chamber.

The disadvantage of the considered technical solution is the reduced head of the screw, which depends on its diameter at the outlet. This can lead to a decrease in the separating properties of the gas separator at high flow rates. Possible formation of reverse currents at the entrance to the separation chamber due to a sharp, stepwise transition between the screw channel and the separation chamber channel. This can lead to waterjet wear and cutting of the gas separator body at the entrance to the separation chamber. To reduce the harmful effect of gas on the energy parameters of the pump: head and efficiency, the design of the pump must be changed.

The closest analogue to the inventive submersible installation is a technical solution known from patent RU 2503808, which discloses a gas separator for a submersible pump containing a housing, a base in which inlets for supplying a gas-liquid mixture are made, a head with outlet openings for removing separated gas and outlet channels for the transfer of degassed liquid, a separation chamber, a shaft, a screw mounted on the shaft, characterized in that a cone-shaped bushing is installed in the housing at the entrance to the separation chamber, the inner diameter of which is less than the outer diameter of the separation chamber.

However, the separation of the flow path of the gas separator into the supply and separation areas is ineffective, since there are no blades on the separating sleeve, and it is not a guide vane. The pressure at the inlet to the separation chamber is less than the pressure at the outlet of the screw by the amount of hydraulic losses in the confuser-diffuser sleeve. Reverse currents arise from the outlet to the inlet of the axle wheel, which reduce the pressure and disperse, crush the diameter of the gas bubbles. The gas separator cannot completely remove all free gas from the stream. At the pump inlet, the free gas content can be up to 25%. To reduce the harmful effect of gas on the energy parameters of the pump: head and efficiency, the design of the pump must be changed.

The technical problem of the claimed utility model is the creation of a technical solution in which during the operation of the gas separator inside it decreases or completely stops the occurrence of countercurrents relative to the main flow of formation fluid (gas-liquid abrasive mixture). As a result, it eliminates dispersion, a decrease in the diameter of gas bubbles, protects the inner surface of the gas separator body from wear, and, as a result, leads to an increase in the reliability of the gas separator. And also the creation of a technical solution in which, during operation, the pressure gradient in the separation area increases, which, along with the elimination or reduction of the dispersion of gas bubbles, increases the efficiency of free gas separation. In this case, it is necessary that continuous dispersion is carried out in the pump in order to maintain a minimum value of gas bubbles, a certain ratio of forces from the pressure gradient and flow rate is observed, at which there is no formation of gas locks and no disruption of the supply.

The technical result of the utility model is to increase the reliability and efficiency of the installation with a gas separator and a vane pump.

The essence of the claimed utility model lies in the fact that in a submersible installation containing a vane pump, a gas separator, an electric motor, each pump stage contains an impeller and a guide vane, between the driving disk of the impeller and the lower disk of the guide vane, an area is formed that is closed on the inside, a gas separator contains a housing, a protective sleeve installed in the housing, sequentially installed on the shaft along the flow of the gas-liquid mixture, a base with holes, a screw, an axial wheel, a head with channels for the passage of the separated liquid into the pump and holes for gas outlet into the annular space, between the screw and the axial a separating sleeve is installed with a wheel, which includes a confuser and a diffuser section, a separating sleeve is installed in a protective sleeve and consists of two parts: a confuser and a diffuser section, blades are made on the confuser section of the separating sleeve, the angle of inclination of which increases from input yes to the outlet, the inner diameter of the separating sleeve is at least 12% less than the inner diameter of the thermowell, the angle of the blades at the outlet of the axle wheel is at least 20% higher than at the outlet of the auger, impellers and guide vanes pumps are made using sand casting technology, the difference between the diameters of the driving and lower disks of the impeller and the guide vanes does not exceed 5%.

The axial wheel can be installed inside the diffuser part of the separator sleeve.

An additional axle wheel and / or drum can be installed behind the axle wheel.

Additional blades can be made on the impeller drive disc.

A helical groove can be made on the inside of the guide vane opposite the outlet from the impeller.

The essence of the technical solution is explained as follows.

If the separator sleeve is installed in a thermowell, then this increases the reliability of the product by eliminating the joints between the sleeves installed in the body. One sleeve without joints is installed in the body. In the joints, reverse currents can occur, which lead to waterjet wear of parts.

The separating sleeve consists of two parts: confuser and diffuser sections in order to reduce costs and improve manufacturability.

On the confuser section of the separating sleeve, blades are made, the angle of inclination of which increases from inlet to outlet. This is necessary in order to effectively separate the areas of separation and supply of liquid lubricants in the gas separator. The vanes in the confuser section convert the velocity head at the outlet of the screw into pressure, thus increasing the pressure at the inlet to the gas separation region of the gas separator.

The inner diameter of the separator sleeve is at least 12% smaller than the inner diameter of the thermowell. This is necessary so that the rotating ring of the partially degassed liquid presses on the stationary ring, and not on the blades of the auger feeding the liquid lubricant of relatively low density. According to studies carried out using numerical modeling and analytical calculations, it was found that this value is optimal.

The blade angle at the exit from the axle wheel is at least 20% higher than at the exit from the auger. The task of the auger is to supply the gas mixture, which requires a relatively low pressure gradient so that the gas freely passes through the auger blade grate without the formation of gas locks and disruption of the feed, respectively, small angles at the outlet of the auger. The axial wheel in the separation chamber must create a high pressure gradient in order to effectively separate the gas, therefore there must be large outlet angles.

The impellers and guide vanes of the pump are made using sand casting technology, with this technology the roughness of the channels of the flow path is greater than with the investment casting technology it is Ra 12.5 GOST 2789-73. As the results of numerical modeling show, it is this value of roughness in the turbulent flow of liquid in the flow path that affects the flow of the main liquid core, ensuring the dispersion of the liquid-liquid mixture, the hydraulic losses are relatively small, so the efficiency remains at an acceptable level.

A cavity is formed between the driving disc of the impeller and the lower disc of the guide vane, which is closed on the inner side by a slotted seal between the hubs of the impeller and the guide vane. Gas bubbles collect in this area. To exclude the exit of a large gas bubble into the flow path, it is necessary that the difference between the diameters of the driving and lower discs of the wheel and the guide vane does not exceed 5%. The value is obtained on the basis of physical experiments.

The axial wheel is installed inside the diffuser part of the separating sleeve in order to increase the reliability of operation, since there will be two sleeves between the wheel and the body: a protective sleeve and a separating sleeve. In addition, the cone-shaped separating sleeve eliminates or significantly reduces the reverse currents between the outlet and the inlet to the axle wheel in off-design operating modes.

An additional axial wheel and / or drum is installed behind the axial wheel installed inside the diffuser part of the separating sleeve in order to increase the pressure and, accordingly, the pressure gradient in the separating chamber.

A module with dispersing multiphase stages is installed between the gas separator and the pump. For the purpose of preliminary dispersion, reducing the diameter of gas bubbles. The smaller the diameter of the bubbles, the better the pump works with the liquid-liquid mixture.

Structurally, the module with compressor dispersing stages can have a common shaft with the gas separator in order to reduce the cost.

In order to disperse the gas in the area between the driving disc of the impeller and the lower disc of the guide vanes, additional blades are made on the driving disc of the pump impellers.

For the purpose of additional dispersion of the liquid lubricant flow, a helical groove is made on the inner part of each guide vane opposite the outlet from the impeller.

The essence of the utility model is illustrated in FIG. 1-5, which show:

Fig. 1 is a diagram of a submersible installation consisting of an engine, a gas separator, a module with compressor dispersing stages, a pump and a tubing;

Fig. 2 is a general view of the gas separator in section with one axial wheel;

Fig. 3 is a general view of the gas separator in section with two axial wheels;

Fig. 4 is a general view of the pump in section with diagonal steps;

Fig. 5 is a general view of a pump in section with centrifugal stages.

In Figs. 1-5, positions 1-31 denote:

1 - electric motor;

2 - gas separator;

3 - module with compressor dispersing stages;

4 - vane pump;

5 - tubing;

6 - body;

7 - protective sleeve;

8 - base;

9 - auger;

10 - axial wheel;

11 - head;

12 - channel;

13 - hole;

14 - separating sleeve;

15 - confuser part of the separating sleeve;

16 - diffuser part of the separating sleeve;

17 - scapula;

18 - shaft;

19 - additional axle wheel and / or drum;

20 - the area of supply of the gas-liquid mixture;

21 - separation area;

22 - pump base;

23 - pump head;

24 - pump casing;

25 - pump shaft;

26 - impeller;

27 - guiding device;

28 - leading disk;

29 - lower disc;

30 - closed area;

31 - additional blades;

32 - helical groove.

The submersible installation contains an electric motor 1, a gas separator 2, a module with compressor dispersing stages 3, a vane pump 4, and tubing 5.

Gas separator 2 contains a housing 6, a protective sleeve 7 installed in the housing, a base 8 with holes, a screw 9, an axial wheel 10, a head 11 with channels 12 for the passage of the separated liquid into the pump 4 and holes 13 for gas outlet into the annulus. A separating sleeve 14 is installed between the screw 9 and the axial wheel 10 in a protective sleeve 7, consisting of two parts: a converging part 15 and a diffuser part 16, blades 17 are made in the converging part 15 of the separating sleeve 14. The axial wheel 10 is installed inside the diffuser part 16 of the separating sleeve 14 on shaft 18.

Behind the axial wheel 10 installed inside the diffuser part 16 of the separating sleeve 14, an additional axial wheel and / or drum 19 is installed on the shaft 18.

The separating sleeve 14 separates the area for supplying the gas-liquid mixture 20 and the area of separation 21.

Vane pump 4 includes a base 22, a head 23, a housing 24, a shaft 25, steps are installed on the shaft. Each stage of the pump includes an impeller 26 and a guide vane 27, between the drive disc 27 of the impeller 26 and the lower disc 29 of the guide vane 27 a region 30 is formed, closed on the inner side.

Additional blades 31 can be made on the driving disc of the impellers 26 of the pump 4.

A helical groove 32 is made on the inside of each guide vane 27 opposite the outlet from the impeller 26.

The device works as follows.

When the engine is turned on, the torque is transmitted to the shaft 18 of the gas separator 2 and the shaft 25 of the vane pump 4.

Formation fluid with an increased content of gas and abrasive particles from the well enters through the holes in the base 8 onto the screw 9. Due to the acquired pressure in the screw 9, the formation fluid with an increased content of gas and abrasive particles passes through the blades 17, while the pressure increases due to the decrease in speed rotation of the flow. The axial wheel 10 rotating on the shaft 18 swirls the flow, providing a high pressure gradient in the separation area 21.

The separating sleeve 14 has a thickened converging-diffuser shape. This shape prevents countercurrents at the periphery from the separation area 21 to the supply area of the gas mixture 20.

Further, the liquid from the periphery of the separation area 20 flows through the channels 12 of the head 11 to the intake of the pump 4 or a module with compressor dispersing stages 3, and the gas is discharged through the holes 13 into the annular space of the well.

Through the base 22 of the pump 4, the flow of the gas-liquid mixture, in which the content of free gas can reach 25%, successively passes through the impellers 26 and the guide vanes 27. In the impellers 26, a pressure is created in the form of an increase in the pressure and rotation speed of the flow, in the guide vanes 27 a part the velocity head is converted to pressure.

Having passed through all the stages, the formation fluid through the head 23 of the pump 4 is fed into the tubing 5 and rises to the surface.

Thus, an increase in the reliability and efficiency of the installation with a gas separator and a vane pump is ensured.

Claims (5)

1. Submersible installation containing a vane pump, a gas separator, an electric motor, each pump stage contains an impeller and a guide vane, between the driving disk of the impeller and the lower disk of the guide vane, an area is formed that is closed on the inside, the gas separator contains a body, a protective sleeve installed in the body a base with holes, a screw, an axial wheel, a head with channels for the passage of the separated liquid into the pump and holes for gas outlet into the annular space, installed in series on the shaft along the course of the flow of the gas-liquid mixture, a separating sleeve is installed between the screw and the axial wheel, including a confuser and diffuser sections, characterized in that the separating sleeve is installed in a protective sleeve, blades are made on the confuser section of the separating sleeve, the angle of inclination of which increases from the inlet to the outlet, the inner diameter of the separating sleeve is at least 12% less than the inner diameter diameter of the protective sleeve, the angle of the blades at the exit from the axle wheel is at least 20% higher than at the exit from the auger, the impellers and guide vanes of the pump are made according to the sand casting technology, the difference between the diameters of the driving and lower discs of the impeller and the guide vane does not exceed 5%. 2. Submersible installation according to claim 1, characterized in that the axial wheel is installed inside the diffuser part of the separating sleeve. 3. Submersible installation according to claim 2, characterized in that an additional axial wheel and / or drum is installed behind the axle wheel. 4. Submersible installation according to claim 1, characterized in that additional blades are made on the driving disk of the impeller. 5. Submersible installation according to claim 1, characterized in that a helical groove is made on the inner part of the guide vane opposite the outlet from the impeller.

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