RU2244852C2 - Well pumping unit - Google Patents

Abstract

FIELD: lifting of liquids from deep wells.

SUBSTANCE: proposed unit contains submersible pump, pressure tubing string, drive shaft consisting of sucker rods whose ends are provided with slots and which are installed inside connectors. The latter are made in form of bushing with inner cylindrical ring groove in middle part and through longitudinal slots on end sections in number corresponding to number of slots on sucker rods, and blind slots located between through slots. Blind slots are made open from side pointed to cylindrical ring groove and are through in radial direction.

EFFECT: improved operation reliability, reduced service expenses, simplified design.

5 dwg

Description

The invention relates to pump engineering, and in particular to pumping units designed to lift fluid from deep wells, mainly from oil, equipped with screw pumps.

A well-known pump installation containing a submersible pump, a column of pressure pipes with flanges, a drive shaft, consisting of sucker rods with threaded ends and couplings, a seal, a bearing and a drive (Catalog of the Moldavgidromash Production Association, Downhole pumping units for water. Moscow: TSINTIHIMNEFNEMASH, 1973 , p.29, 36).

The closest in technical essence to the proposed one is a pumping unit, including a submersible screw pump, a column of pressure pipes, a drive shaft consisting of sucker rods, couplings, bearings, wellhead seals, a thrust bearing and a drive fields - at sea or on land, 1992, NEMO pumps for pumping water-oil-sand mixtures - for servicing wells).

The disadvantages of the devices both by analogy and prototype are:

- unsatisfactory operational reliability due to a violation of the threaded connections of the sucker rods due to the large axial forces on the threads, arising during the start-up of the pumping unit;

- significant operating costs due to the need for a large amount of preparatory and machine (technological) time for connecting and disconnecting the sucker rods;

- design complexity due to the presence of a device that prevents the rotation of the sucker rods in the opposite direction.

The objective of the invention is the creation of a pumping unit with high operational reliability, low operating costs and simplified design.

This problem is solved by the proposed borehole pump installation, including a submersible screw pump, a column of pressure pipes, a drive shaft consisting of sucker rods, couplings and bearings, wellhead seal, pillow block bearing and drive.

What is new is that the ends of the sucker rods of the drive shaft are provided with slots and installed inside the couplings, each of which is made in the form of a sleeve with an inner cylindrical annular selection in the middle part and longitudinal through grooves in the end sections according to the number of splines of the sucker rods and blind grooves located between through, and the blind grooves are made open from the side facing the cylindrical annular sample, and through in the radial direction.

Figure 1 shows the proposed pump installation in longitudinal section.

In Fig.2 - the connection node of the pump rods in longitudinal section.

Figure 3 is a section of the pump rod along the spline section.

Figure 4 is a longitudinal section of a coupling.

In Fig.5 is a section along aa and bb of Fig.4.

The pump installation consists of a deep-well submersible screw pump 1 (Fig. 1), a column of pressure pipes 2 (tubing) with couplings 3 connected at the wellhead to a support flange 4 and a branch elbow 5. The pump shaft is connected to the drive shaft 6, consisting of hollow sucker rods 7, supported on supports 8 installed in the pressure pipes 2. The ends of the sucker rods 9 (Fig.2) are made integral, welded to the hollow part of the rods, provided with slots 10 (at least two) (Fig.3) and installed inside the couplings 11. The latter are made in the form of bushings and an inner cylindrical ring sample 12 in the middle part (4), the through longitudinal slots 13 on the end portions of the splines on the number of sucker rods and blind-grooves 14 disposed between the through (5). Blind grooves are made open from the side facing the cylindrical annular sample, and through in the radial direction. The latter is dictated by manufacturing capabilities.

At the wellhead in the casing 15 (Fig. 1) mounted on the support flange 4, there is a wellhead seal 16, a thrust bearing 17, and on top of the casing is a pump drive 18, to which the drive shaft 6 is connected.

The descent of the installation into the well is as follows.

At the wellhead, the first (lower) pump rod 7 is connected to the pump shaft 1 and the first (lower) pressure pipe 2 with the pump housing and the coupling is lowered into the well to the depth of the first pipe and mounted on the mouth on the clamp. Then, the first support 8 is installed and the connecting sleeve 11 is inserted at the end of the first pump rod, lowering it through the grooves 13 to the position of the slots 10 opposite the ring sample 12, turn the coupling 11 to align with the lower blind grooves 14 and lift it to the stop of the splines in the lower ledges 19. After that, the second pump rod with the second pressure pipe and coupling is lifted on the clamp, the lower end of the pump rod is inserted from above into the coupling until its splines are aligned with the ring selection and the rod is turned until it is aligned with the top them with blind grooves, lift it up to the stop of the slots in the upper ledges 20 - the connection is ready. Then a second pressure pipe is wrapped. All subsequent pressure rods and pressure pipes are connected in a similar way.

At the wellhead, the last pressure pipe is installed on the casing and connected to the branch elbow 5, and the last pump rod to the drive shaft 18.

When the drive shaft 18 (electric motor) rotates, the first pump rod from above 6 through the slots, acting on the side walls of the blind grooves, transmits torque to the adjacent pump rod through its slots. Torque is transmitted in a similar manner to subsequent sucker rods.

The submersible pump 1, receiving rotation from the sucker rods, delivers the pumped liquid from the bottom of the well under pressure into the pressure pipes, which, having reached the wellhead, through the outlet bend 5 is sent to the surface pipeline.

Application of the proposed installation will allow:

- reduce operating costs due to a sharp reduction in the time to connect and disconnect the sucker rods;

- increase operational reliability due to the fact that the transmission of torque from the first pump rod to the pump shaft is not sharp due to the fact that between the previous and subsequent pump rods there is a circumferential displacement, which leads to a smooth transmission of torque from the drive to the pump;

- to simplify the design by eliminating the braking device from it (in the proposed device, the rotation of the drive shaft can be carried out in one direction or another).

Claims (1)

A downhole pump installation including a submersible screw pump, a column of pressure pipes, a drive shaft consisting of sucker rods, couplings and bearings, a wellhead seal, a thrust bearing and a drive, characterized in that the ends of the sucker rods of the drive shaft are provided with slots and installed inside the couplings each of which is made in the form of a sleeve with an inner cylindrical annular selection in the middle part and longitudinal through grooves at the end sections according to the number of splines of the sucker rods and blind grooves and located between the through, and the blind grooves are made open from the side facing the cylindrical annular sample, and through in the radial direction.

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