RU145676U1 - SEPARATOR FOR CLEANING WELL LIQUID FROM MECHANICAL IMPURITIES - Google Patents

Abstract

1. The separator for cleaning well fluid from mechanical impurities, containing the outer and inner pipes installed concentrically with the formation of an annular gap, in which is placed a guide vane in the form of a constant-pitch screw, holes for entering the fluid flow into the annular gap, made in the upper part of the outer pipe and a container for collecting separated mechanical impurities, characterized in that the guide vane is made with an input angle of 20-45 °, and is placed in the upper part of the annular gap, and the length of and the inner tube below the blades is determined from vyrazheniyagde Q - rate of the formation fluid, δ - the height of the screw blade, S - area of the annular gap, ν - viscosity of the fluid, k - the coefficient equal to 0.0015 ± 0,0005.2. The separator according to claim 1, characterized in that a coaxial pipe is mounted in the bottom of the container for collecting the separated mechanical impurities, which ensures the removal of mechanical impurities into the sump of the well. The separator according to claim 1, characterized in that at least one additional guide vane is located in the annular gap.

Description

The utility model relates to the oil industry and can be used to protect the ESP from clogging and hydroabrasive wear by mechanical impurities.

Known separator for cleaning well fluid from mechanical impurities, consisting of external and internal concentrically installed pipes with the formation of an annular gap, in the upper part of which there is a helical guide vane equipped with a container for accumulating separated particles of mechanical impurities and a safety valve made with the possibility of hydraulic connection of the intake pump with annulus provided that the movement of the pumped liquid through the separator is stopped. The outlet of the purified liquid from the separator is hydraulically connected to the intake of the pump. The separator includes a hydrocyclone consisting of a removable insert with a given taper angle and a replaceable nozzle on top of a cone with a given diameter (RF patent No. 64417, E21B 43/38, 04/10/2007).

The disadvantage of this device is the need for selection and change of insert and nozzle in a hydrocyclone. Unlike surface hydrocyclones, in this device the space under the cone is muffled, and there is no point in using replaceable nozzles on the top of the cone, since in this case there is no fluid flow through the nozzle.

Known separator for cleaning well fluid from mechanical impurities, which is part of a submersible well installation for oil production, consisting of external and internal concentrically installed pipes with the formation of an annular gap along the entire length of which is placed a helical guide vane equipped with a container for accumulating particles separated in the separator mechanical impurities. The outlet of the purified liquid from the separator is hydraulically connected to the pump intake (patent GB 2409691, E21B 43/34, 03/05/2003).

The disadvantage of this device is the insufficiently high degree of purification due to the occurrence of vortices at the outlet of the annular gap when the flow rotates into the inner pipe, causing mixing of solid particles and deterioration of separation.

The technical advantage of the proposed utility model is to improve the degree of purification of the well fluid from mechanical impurities.

This result is achieved by the fact that in the separator for cleaning well fluid from mechanical impurities, containing the outer and inner pipes installed concentrically with the formation of an annular gap, in which the guide vane in the form of a constant-pitch screw is placed, made in the upper part of the outer pipe of the hole for the flow inlet liquid in the annular gap and the container for collecting separated mechanical impurities, according to the utility model, the guide vane is made with an input angle of 20-45 degrees, and size bezel at the top of the annular gap, and the length of the portion of the inner pipe below the blade is determined from the expression L = f (Q), where Q is the flow rate of the formation fluid, δ is the height of the screw blade, S is the area of the annular gap, ν is the viscosity of the fluid, k coefficient equal to 0.0015 ± 0.0005.

In the bottom of the container for collecting the separated mechanical impurities, a coaxial pipe can be mounted, providing the removal of mechanical impurities in the sump of the well.

To improve the degree of purification of the borehole fluid from mechanical impurities, at least one additional guide vane can be placed in the annular gap.

To clarify the essence of the claimed device, we consider the design diagram of the separator shown in FIG.

The separator consists of an outer pipe 1 with holes 2 for liquid inlet and an inner pipe 3, forming an annular gap 9 between themselves, in the upper part of which there is a fixed guide vane in the form of a constant pitch screw 4. The vane 4 is located so that the inner tube 3 continues after the end of the blade 4 at a distance where Q is the flow rate of the formation fluid, δ is the height of the auger blade, S is the annular gap area, ν is the viscosity of the fluid, k is a coefficient depending on the angle of winding of the blade on the inner tube 3. From below, the separator is equipped with a container 5 for collecting separated mechanical impurities. The container 5 may be a continuation of the outer pipe 1 or made separately with subsequent rigid attachment to the bottom of the separator. To prevent overflow in the container 5, a coaxial pipe 6. is installed. In order to ensure the flow of liquid through the separator, a seal or packer 8 is installed above the space between the casing and tubing 8. To improve the separation properties of the device, two rings can be located in the annular gap 9 or more motionless blades 4.

The separator for cleaning well fluid works as follows.

The flow of the borehole fluid through the holes 2 enters the annular gap 9 of the gravity separator, moves down the guide vane of the screw 4 and, bending around the lower end of the outer pipe 3, rises up its inner cavity, and then moves to the pump intake. When moving along the annular gap 9 under the action of centrifugal force, the flow is divided, the particles are twisted and pressed against the walls of the outer pipe 1. To reduce vortex formation, the inner pipe 3 is made with the extension of the auger 4 over a distance of as a result of which the fluid after twisting moves along the annular gap formed by the continuation of the inner pipe 3 and the outer pipe 1. At the same time, particles are separated and the flow is aligned along the axis due to a decrease in the peripheral velocity component. The absence of fluid rotation avoids the formation of intense vortices that prevent the separation of solid particles when the flow is turned at the end of the pipe 3.

The coefficient k depends on the angle of winding the blades on the inner pipe 3. Most often, the blades are used with the angle of winding on the inner pipe 20-45 °, for this range of values the coefficient k is 0.0015 ± 0.0005.

When the coefficient k is less than 0.001, the flow does not have time to align along the axis before it is turned at the end of the pipe 3, which will lead to the formation of intense vortices and poor separation. When the coefficient k is greater than 0.002, due to the large length of the pipe, it is not possible to maintain the level of particle separation achieved when the fluid moves in a spiral along the blade.

When leaving the annular gap 9, the main flow is rotated through 180 °, while large particles of mechanical impurities under the influence of gravity fall down, accumulating around the bottom of the container 5 around the pipe 6, and the purified liquid enters the pipe 3, rises along it and enters pump installation. In order to avoid an upward flow of fluid through the pipe 6, it must have sufficient hydraulic resistance - greater than the resistance of the separator. This is achieved due to the optimal selection of the length and diameter of the pipe 6. When the container 5 is full, when the level of impurities becomes higher than the upper end of the pipe 6, solid particles are discharged through it into the sump of the well. The fineness of cleaning will be determined by the ratio of the forces of viscous friction of particles on a liquid, Archimedean force, centrifugal force and particle weight.

Claims (3)

1. The separator for cleaning well fluid from mechanical impurities, containing the outer and inner pipes installed concentrically with the formation of an annular gap, in which is placed a guide vane in the form of a constant-pitch screw, holes for entering the fluid flow into the annular gap, made in the upper part of the outer pipe and a container for collecting separated mechanical impurities, characterized in that the guide vane is made with an input angle of 20-45 °, and is placed in the upper part of the annular gap, and the length of and the inner tube below the blade is defined by the expression $$L=k\frac{{\delta }^2}{\nu }\cdot \frac{Q}{S},$$

where Q is the flow rate of the formation fluid, δ is the height of the auger blade, S is the annular gap area, ν is the fluid viscosity, k is a coefficient equal to 0.0015 ± 0.0005. 2. The separator according to claim 1, characterized in that a coaxial pipe is mounted in the bottom of the container for collecting the separated mechanical impurities, which ensures the removal of mechanical impurities into the sump of the well. 3. The separator according to claim 1, characterized in that at least one additional guide vane is placed in the annular gap.