RU2354821C1 - Device for separation of solid particles and gas in submerged electric centrifugal pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention is related to oil machine building and may be used in submerged electric centrifugal pumps that pump gas-liquid mixtures with high content of solid particles from wells. Device comprises body, shaft, receiving base with channels and mesh for passage of well liquid, separator, channel for gas discharge, channel for discharge of separated liquid, channel for discharge of solid particles connected to container. Inside separator there is axial wheel installed, which is arranged with upper annular disc with internal channel for gas discharge. Ends of wheel blades and internal part of separator are arranged as cone-shaped. Above disc on shaft there is baffle installed, which is arranged in the form of cruciform radial blades, and fixed protective grid, above which compressing wheel is located. Suggested design will make it possible during pump operation to separate gas-liquid mixture with solid particles after supply to device in three flows: gas, liquid and solid particles with their direction along their motion channels due to effect of centrifugal forces.

EFFECT: increased efficiency of pumps operation in crooked wells having viscous, highly carbonated liquid and high content of solid particles.

1 dwg

Description

The invention relates to petroleum engineering and can be used in submersible electric centrifugal pumps that pump gas-liquid mixtures with a high solids content from wells.

A device for the separation of solid particles and gas of a submersible electric pump, consisting of a conical-cylindrical hydrocyclone with tangential openings for supplying well fluid and an ejector mounted on a pressure line. The hydrocyclone solids collection chamber and the ejector are made together in the same volume along the fluid path, and the pipeline for supplying the purified fluid to the pump is laid along the pump casing next to the power cable (RF patent No. 2186252, publ. 2002). This device will stop working if the collection chamber is filled with large solid particles with a diameter incommensurable with the diameter of the channels of the mixing chamber and the diffuser. The diameter of the cross-section of the pipeline is limited by the thickness of the cable, which increases hydraulic losses in it and reduces the efficiency of the pump, especially when pumping high-viscosity oils and high flow rates of the well, increases the conditional diameter of the pump and installation as a whole, which makes it impossible to place in the well without bending. During hoisting operations of the pumping unit, dents or depressurization of the pipeline are not guaranteed. A set of functionality limits the use of inefficient creation of a process of centrifugal separation of solids and gas due to the tangential execution of large holes, especially at low flow rates of the incoming fluid.

Known submersible pumping unit for oil production, containing a lowered pump with a submersible electric motor, a centrifugal separator of solid particles and a sump (patent No. 2278959, publ. June 27, 2006). The centrifugal separator is located below the submersible motor with the possibility of transmission from the motor shaft to the shaft of the centrifugal separator, while the separator rotor is surrounded by a fixed helical grill with slicing blades opposite to the movement of the fluid flow and the direction of rotation of the separator rotor. The electric motor also contains a casing hydraulically connecting the pump intake and the cavity of the centrifugal separator.

The disadvantages of the device include:

- the separator screw grill creates an oncoming flow to the fluid moving through the separator to the pump intake and at a certain viscosity of the produced mixture, the separator can be blocked by oncoming flows, i.e. the produced mixture will go to the pump, bypassing the separator;

- in the case of a casing, the diameter of which will significantly exceed the diameter of the electric motor, this will lead to an increase in the nominal diameter of the electric centrifugal pump installation (ESP).

In general, any increase in the diameters of the electric centrifugal pump (ESP), submersible electric motor (SEM), or any other components (ESP), for example gas separators, overflow couplings, etc. significantly increases the requirements for placing the ESP in the well without bending. Complicated opportunities for tripping due to an increase in the nominal diameter of the ESP.

The device has limited capabilities for the reliability of the operation of the ESP in directional wells with the existing increased viscosities and gas contents of the extracted gas-oil mixtures.

The closest technical solution is a gas separator for an ESP type MN (K) -GSL, which consists of a tube body with a head, a base with a receiving grid and a shaft with parts located on it. Two cross channels for gas and liquid are made in the head. At the base there is a cavity closed with a mesh with channels for receiving a gas-liquid mixture with solid particles. Heel, auger, axial impeller, separator are placed on the shaft. The guide grill and sleeves are placed in the casing (Installations of submersible centrifugal pumps for oil production: International translator. / Under the editorship of V.Yu. Alekperov, V.Ya. Kerzhenbaum, Oil and Gas, 1999 - 611; ill., see p. 293-299 - prototype.

However, the disadvantage of this device is the decrease in reliability when pumping gas-liquid mixtures with a high content of solid particles, which in practice leads to clogging and premature abrasive wear of the gas separator parts.

The aim of the invention is to increase the efficiency of the ESP in deviated wells having a viscous highly carbonated liquid and a high solids content.

The goal is achieved in that the device for separating solid particles and gas of an electric submersible centrifugal pump, located under the pump, contains a housing, a shaft, a receiving base with channels and a grid for the passage of well fluid, a separator, a channel for exhausting gas, a channel for removing the separated fluid, a channel for removal of solid particles, connected to the container, an axial wheel is placed inside the separator, made with an upper annular disk with an internal gas exhaust channel, the ends of the wheel blades and the inner part of the separator Nena tapered over drive shaft disposed bump configured as a cruciform radial blades and stationary protective screen above which is compressed taken wheel.

The proposed design will allow the pump to obtain the separation of the gas-liquid mixture with solid particles upon entering the device into three streams: gas, liquid and solid particles with their direction through their channels of motion due to the action of centrifugal forces. The removal of solid particles into the container reduces the possibility of clogging and abrasive wear of the device and ESP, and gas outside the device, which increases the reliability of their work. In this case, the diametrical dimensions of the device do not exceed the diameter of the ESP.

The drawing schematically shows the inventive device.

A device for separating solid particles and gas from a submersible electric centrifugal pump is located under the lower part of the pump and includes a pipe housing 1 with a separator 2 and a guiding grid 3 located therein, a shaft 4 with an axial wheel 5 mounted on it and placed inside the separator 2. Wheel 5 is made with the upper annular disk 6 with an internal channel for the passage of gas along the shaft 4. The ends of the blades of the wheel 5 and the inner part of the separator 2 are conical to ensure the removal of solid particles through the channel 7 into the container 8, placed od receiving base 9 with the grid. Above the disk 6 on the shaft 4 there is a chipper 10 made in the form of crosswise radial blades, and a fixed protective grill 11. At the ends of the device are placed the upper head 12 and lower head 13, which are used to connect to the ESP and hydraulic protection. In the upper head, a channel 14 is made for the passage of liquid into the ESP and a channel 15 for the removal of gas outside the device. Above the grate 11, a compression wheel 16 is placed on the shaft 4, which facilitates the removal of gas.

The device operates as follows. When the pump is operating, the gas-liquid mixture with solid particles from the well enters through the channels of the receiving base 9 into the separator 2, where, under the action of centrifugal forces created by the axial wheel 5, the mixture is distributed in density. The heaviest components of the mixture: solid particles and liquid are thrown to the periphery to the wall of the separator 2. At the same time, solid particles bounce down at an angle against the wall of the separator 2 and, falling into the guide grid 3, lose peripheral speed and settle along channel 7 into the container 8 The volume of the container varies depending on the expected concentration of solid particles in the produced mixture. The liquid due to the operation of the pump through channel 14 enters the pump. Under certain conditions, liquid can carry away individual solid particles. In this case, these particles are retained by the protective mesh 11, and the fender 10 removes particles from the protective grill 11 with its vanes and throws the particles into the separator 2. Gas, as the lightest component, is collected in the center of the axial wheel 5 and is removed through centrifugal forces through the annular channel along the shaft 4 to the compression wheel 16, which facilitates the movement of gas into the channel 15 and beyond the device, into the annulus.

The introduction of the device will significantly increase the operating time to failure of the ESP in comparison with the existing solid-particle gas-liquid medium during pumping.

Information sources

1. RF patent No. 2186252, publ. 2002 year

2. RF patent No. 2278959, publ. 06/27/2006

3. International translator. / Ed. V.Yu. Alekperova, V.Ya. Kerzhenbaum, “Oil and Gas”, 1999 - 611; ill., pp. 293-299 - prototype.

Claims (1)

A device for separating solid particles and gas of a submersible electric centrifugal pump, located under the pump, comprising a housing, a shaft, a receiving base with channels and a grid for the passage of well fluid, a separator, a channel for removing gas, a channel for removing the separated liquid, a channel for removing solid particles, connected to the container, characterized in that an axial wheel is arranged inside the separator, made with an upper annular disk with an internal gas exhaust channel, the ends of the wheel blades and the inner part of the separator They are cone-shaped, a chipper made in the form of cross-shaped radial blades, and a fixed protective grill, above which a compression wheel is placed, are placed above the disk on the shaft.