RU216606U1 - Coupling for connecting sucker rods - Google Patents

Abstract

The utility model relates to the oil industry, in particular for use in the mechanized method of oil production using downhole sucker rod pumping units, and can be used to connect sucker rods. The technical objectives of the utility model are: increasing the reliability of the rod string coupling, which ensures the exit of air or liquid from the coupling cavity while maintaining a margin of safety in the central cross section of the structure, as well as simplifying maintenance by the possibility of prompt elimination of the pump rod deflection without lifting them during operation. The coupling for connecting the sucker rods contains a coupling body with a connecting pipe thread, divided by a solid transverse stiffening rib into two sections with independent pipe threads of the same size and a round internal chamfer at the junction areas of the solid transverse stiffening rib with the coupling body. In the coupling body, through flushing channels are made, one above and below the stiffening rib, located from the round inner chamfer of the coupling to the middle of the stiffening rib, at an acute angle to the coupling axis, and directed in parallel. The proposed design of the coupling for connecting the sucker rods is reliable, providing the exit of air or fluid from the cavity of the coupling while maintaining a margin of safety in the central cross section of the structure, and also simplifies maintenance with the possibility of prompt elimination of the sucker rod deflection without lifting them during operation.

Description

The utility model relates to the oil industry, in particular for use in the mechanized method of oil production using downhole sucker rod pumping units, and can be used to connect sucker rods.

Known standard coupling pump rods (GOST 13877-96), represented by a cylindrical body with a through thread of the same size on both sides. However, this device does not take into account the presence of a stress concentration zone in the central cross section of the coupling body. Also, the disadvantage of this coupling is that when the pump rods are screwed together, a sealed cavity may form in it due to the filling of the thread groove with lubricant, which prevents the release of air, condensate or water in case of tripping operations during precipitation. In addition, in the case of rod backlash during operation, during the subsequent elimination of rod backlash during resuscitation work or by the drilling crew, a complete high-quality inversion of the rods is not possible due to the presence of remnants of the well fluid in the sleeve (the fluid does not compress), so the effect of resuscitation will be short-lived , and when carrying out the PRS, it will be necessary to lift the rod string to the rod with incomplete turning of the coupling and re-launch the raised rods.

Known anti-flight rod coupling (patent RU No. 10777, E21B 43/00, publ. the body has a through hole connecting the inner cavity with the space behind the outer surface.

Known coupling for connecting sucker rods (patent RU No. 25036, E21B 17/042, publ. 10.09.2002 in bull. No. 25), containing a hollow cylindrical body with an internal thread, grooves and chamfers for the exit of a thread-forming tool, characterized in that in it additionally has a groove located along its longitudinal axis, connecting the threads, and the bottom of the groove is located in the housing body behind the surfaces of the thread cavities.

A well-known anti-flight rod clutch (patent RU No. 66773, E21B 17/02, publ. 27.09.2007), containing a housing with an internal cavity, on which a thread is made, characterized in that one or more through holes are made in the central part of the clutch housing.

A common disadvantage of couplings is that the hole or groove is made directly in the body of a standard coupling, reducing the cross section, reducing the constancy of the thickness of the coupling wall in the threaded section, which means that the reliability of the coupling design is reduced.

The closest is a two-section rod string coupling (patent RU No. 134981, IPC E21B 17/042, publ. 11/27/2013 in bull. No. 33), containing a coupling body with a connecting pipe thread, characterized in that the coupling body is separated by a continuous transverse rib stiffness into two sections with independent pipe threads of the same size and a round internal chamfer at the junction of a solid transverse stiffener with the coupling body.

The coupling has a higher strength of the entire part to breaking loads compared to the standard one due to the stiffening rib, but due to the presence of this stiffening rib, it leads to the formation of a sealed cavity with air or liquid by restricting the exit of air or liquid from the coupling cavity, which reduces the reliability of the connection sucker rods and leads to difficulties in maintaining the device, as it does not allow to eliminate the lapel of the rods without lifting them.

The technical objectives of the utility model are to increase the reliability of the rod string coupling, which ensures the exit of air or liquid from the coupling cavity while maintaining a margin of safety in the central cross section of the structure, as well as to simplify maintenance by the possibility of prompt elimination of the sucker rod deflection without lifting them during operation.

Technical problems are solved by a coupling for connecting sucker rods, containing a coupling body with a connecting pipe thread, divided by a solid transverse stiffener into two sections with independent pipe threads of the same size and a round internal chamfer at the junction areas of a solid transverse stiffener with the coupling body.

What is new is that in the body of the coupling, through flushing channels are made, one above and below the stiffening rib, located from the round inner chamfer of the coupling to the middle of the stiffening rib, at an acute angle to the coupling axis, and directed in parallel.

Figure 1 shows a diagram of a coupling for connecting sucker rods.

1 - coupling body, 2 - connecting thread, 3 - round internal chamfer, 4 - through flushing channels, 5 - stiffener.

The device comprises a coupling body with a connecting pipe thread divided by a solid transverse stiffening rib into two sections with independent pipe threads of the same size and a round internal chamfer at the junction areas of the solid transverse stiffening rib with the coupling body.

In the coupling body, through flushing channels are made, one above and below the stiffening rib, located from the round inner chamfer of the coupling to the middle of the stiffening rib, at an acute angle to the coupling axis, and directed in parallel.

The channels made in the area of the stiffening rib provide the exit of air, lubricants, condensate, water, well fluid when the pump rods turn, even in the case of elimination of the turn of the pump rods without lifting the rod string, while the coupling retains a margin of safety in the central cross section of the structure. Since the channels are made in the zone of the stiffening rib, this makes it possible to ensure the constancy of the wall thickness of the coupling in the threaded section, and, therefore, to increase the reliability of its design. The parallel direction of the channels partially prevents the flow of fluid into the coupling cavity.

Examples of execution of a coupling for connecting sucker rods

Example No. Stiffener width, mm Diameter of channel openings, mm Angle of flushing channels to the coupling axis, degrees 1 4 3 73 2 6 3.5 67 3 8 4 63

The coupling for connecting the sucker rods works as follows.

Before screwing, the threaded connection is cleaned of dirt and lubricated. For twisting, the threaded end of the rod is inserted into the sleeve, and then fastened to failure.

The proposed design of the coupling for connecting the sucker rods is reliable, providing the exit of air or liquid from the cavity of the coupling while maintaining a margin of safety in the central cross section of the structure, and also simplifies maintenance with the possibility of prompt elimination of the sucker rod deflection without lifting them during operation.

Claims (1)

Coupling for connecting sucker rods, containing a coupling body with a connecting pipe thread, divided by a solid transverse stiffener into two sections with independent pipe threads of the same size and a round internal chamfer at the junction areas of a solid transverse stiffener with the coupling body, characterized in that in the coupling body through flushing channels are made, one above and below the stiffening rib, located from the round inner chamfer of the coupling to the middle of the stiffening rib, at an acute angle to the coupling axis, and directed in parallel.

Images