RU2743035C1 - Hydraulic anchor for fixing tubings in wells with rod pumps (variants) - Google Patents

Abstract

FIELD: oil-producing industry.

SUBSTANCE: invention relates to the oil-producing industry, in particular to devices for fixing a tubing (TS) string in a casing string (CS) during oil extraction by well rod pumping units. The hydraulic anchor for fixing tubings in wells with rod pumps comprises a body with a longitudinal through channel and a hydraulic chamber communicating to it with fixing elements which are actuated by a pressure differential. The fixing elements are designed in the form of an elastic element of an inflatable packer or radial piston flaps which are spring-loaded with a return spring. The hydraulic chamber is connected to the cavity of the TS by a pipe via a channel in the upper part of the body and is insulated from the longitudinal through channel of the body.

EFFECT: technical result consists in increased reliability of the anchor extraction and simplified work for mounting said anchor and tensioning the TS string.

4 cl, 4 dwg

Description

The invention relates to the oil industry, in particular to a device for fixing a tubing string (tubing) in a production string (EC) during oil production with sucker rod pumping units.

During the operation of the sucker rod pump, changes in the length of the rods and the tubing string occur as a result of the action of pressure variables during the cycle, as well as the spiral bending of the tubing string. This leads to wear of the rods and tubing, as well as a decrease in pump efficiency due to loss of stroke. To prevent these phenomena, the lower part of the tubing string is fixed to the EK using mechanical or hydraulic anchors.

In some cases, tubing tension is additionally applied to increase the effect. To do this, after landing the mechanical or hydraulic anchor, the tubing string is tensioned, which is a very difficult operation associated with the replacement of pipes or nozzles in the tubing string for fitting to wellhead equipment.

There is also a hydraulic method for tensioning the tubing string when using hydraulic anchors by creating the required excess pressure inside the tubing string (patent RU No. 2681770, IPC E21B 23/01, F04B 47/02, publ. 03/12/2019, bull. No. 8).

Known mechanical anchor (NPF "Packer", product catalog No. 17, pp. 72-73) for fixing the tubing string, containing a body, wedge and wedge dies.

Its disadvantages are the high accident rate due to the difficulty of extracting from the well after long-term operation and “sticking” of the wedge dies, as well as the difficulty of creating tension in the tubing string if necessary.

The closest in technical essence to the proposed anchor of hydraulic action (patent RU No. 2634316, IPC Е21В 23/06, 33/1295, publ. 25.10.2017, bul. No. 30), containing a body with a through channel communicated with the tubing , communicated by a hole with a hydraulic chamber, communicated with a piston, interacting under the action of a pressure drop with fixing elements in the form of wedge dies.

Its disadvantages are the complexity of extraction due to sticking of wedge dies on the inner surface of the EC, the complexity of the tubing string tension.

The technical objectives of the present invention are to improve the reliability of the extraction of the anchor and to simplify the installation and tension of the tubing string.

These technical problems are also solved by a hydraulic anchor for fixing tubing - tubing in wells with sucker rod pumps, containing a housing with a through longitudinal channel and a hydraulic chamber connected with it with fixing elements triggered by a pressure difference.

The novelty is that an elastic element of an inflatable packer or radial pistons spring-loaded by a return spring are used as fixing elements, and the hydraulic chamber is connected to the tubing cavity by a tube through a channel in the upper part of the body and is isolated from the longitudinal through channel of the body.

It is also new that a barrel is installed in the armature body with pistons, isolating the communication of the hydraulic chamber with the longitudinal through channel of the body.

It is also new that the tube connecting the tubing cavity with the hydraulic chamber is equipped with a spring-loaded check valve with a shut-off element and a device for forced communication with the tubing cavity.

It is also new that the device for forced communication is made in the form of a sliding sleeve bounded by stops, closing the opening in the tubing and interacting with a counterpart mounted on the rods.

FIG. 1 shows a hydraulic action anchor (HPA) from an inflatable packer.

FIG. 2 - YAGD with piston rams.

FIG. 3 - YAGD from an inflatable packer with a check valve and a pressure relief system.

FIG. 4 - YAGD with piston rams, a check valve and a pressure relief system.

YAGD from an inflatable packer (Fig. 1) contains a housing 1 with a borehole 2, which is wearing an elastic element 3, hermetically fixed by one end on the housing 1, connected from above with the tubing 4, on which a sucker rod pump 6 with a string is lowered into the well with an EK 5 rods 7.

The body 1 YAGD (Fig. 2) is made with radial windows 8, in which the ram-pistons 9 with a notch 10 at the outer end, spring-loaded by a return spring 11, are hermetically installed and connected from above to the tubing 4, on which the sucker rod pump 6 is lowered.

When the YAGD is placed below the pump (Fig. 1 and 2), the tubing cavity 4 is communicated with the hydraulic chambers 12 by the tube 13 and channels 14, and the hydraulic chambers 12 at the YAGD with piston rams 9 (Fig. 2) are isolated from the channel 14 by the barrel 2 with the channel 15.

For the possibility of pre-tensioning the tubing 4 (Figs. 3 and 4), a check valve 16 is installed at the entrance to the tube 13 with an adjustable compression of the spring 17 of the locking element 18 (ball). And below the valve 16, an opening 19 is made, which communicates the tube 13 with the tubing cavity 4, which is covered by a sliding sleeve 20 with upper 21 and lower 22 stops, interacting with a counterpart, for example, an elastic element 23 mounted on the rods 7. The pressure in the EC 5 cavities is higher and below the elastic element 3 (Fig. 3) is aligned through the hole 24.

YAGD works as follows.

After lowering the sucker rod pump 6 (Fig. 1), the drive (not shown in the figure) is put into operation at a predetermined interval, the rods 7 drive the pump 6.

As a result of its operation, the liquid level in EC 5 decreases, and the pressure in the tubing 4 cavity increases. Under the influence of the pressure difference, the produced fluid enters through the pipe 13 into the hydraulic chamber 12 and through it is also dumped back when lifting the equipment from the wells, while the borehole 2 near the NAG (Fig. 1) isolates the chamber 12 from the fluid in the channel 14. The fluid inflates the elastic element 3 and tightly presses it against the wall of EC 5, ensuring due to friction the exclusion of displacement of tubing 4 relative to EC 5 and increasing the efficiency of the pump 6.

In the YAGD (Fig. 2), the liquid in the channel 14, which is also the hydraulic chamber 12, pushes the pistons 9 in the windows 8 against the stop against the wall of the EC 5 and presses them tightly against it. Notches 10 on dies 9 cut into the wall of EC 5 and provide fixation of tubing 4 in EC 5.

When removing the equipment, the pump 6 is stopped and the pressure in the cavity of the tubing 4 is equalized with the pressure inside the EC 5. In the absence of a pressure drop, the elastic element 3 (Fig. 1) is compressed and releases the tubing 4, and the pistons 8 are returned by the spring 11 (Fig. 2) into the transport position and the YAG releases the tubing 4 for lifting.

In this case, the pressure in the cavities of the EC 5 above the elastic element 3 (Fig. 3) is equalized through the hole 24 and the grooves on the surface of the elastic element 3 are not necessary.

The work of the YAGD (Fig. 3 and 4) differs in that before the engagement of the fixing elements, the elastic element 3 or the pistons 9, the tubing 4 is tensioned, which occurs automatically. After starting the pump 6 drive, the pressure difference between the tubing cavity 4 and the EC 5 cavity increases, but the valve 16 remains closed until the pressure difference overcomes the pre-compression forces of the spring 17 and moves the ball 18 from the seat and opens the valve 16.

Under the action of this pressure drop, the tubing 4 is pulled out and both NAGs fix the tubing 4 in an already taut state. If necessary, a stronger tension in the tubing 4 can be achieved with an appropriate adjustment of the compression of the spring 17 and pumping fluid from the wellhead into the tubing 4 with a higher pressure than due to the operation of the pump 6. This pressure remains in the cavity of the hydraulic chamber 12 until the equipment is removed from the well.

To equalize the pressures in the cavities of the hydraulic chamber 12 and tubing 4, a forced equalization mechanism is used.

When the plunger of the pump 6 is lowered, the reciprocal elastic element 23 moves the sliding sleeve 20 to the extreme lower position until it stops 22, and, being compressed, passes through it. In this position, it closes the hole 19 and remains there for the entire duration of the well operation. In this case, the pressure in the cavities of the EC 5 above and below the elastic element 3 (Fig. 3) is equalized through the hole 24.

When removing the equipment from the well, the string of rods 7 with a plunger is first lifted, the elastic element 23 moves the sleeve 20 to the uppermost position until it stops 21, and compresses, passes through it, as in the subsequent plunger of the pump 6. The hole 19 opens and the pressure in the cavity The tubing 4 and the cavities of the fixing elements are aligned. Then this pressure is equalized with the pressure in EC 5, elastic element 3 or ram-pistons 9 move away from the walls of EC 5 and release tubing 4.

Thus, the proposed YGD allows you to easily fix the tubing string in wells with a sucker rod pump from movement without wedge mechanisms and easily release it if necessary. In this case, the fixation occurs automatically. A more complex design allows the tubing string to be tensioned also without manipulation at the wellhead. The absence of wedge mechanisms ensures an easy and reliable disconnection of the NAG from the EC.

Claims (4)

1. An anchor of hydraulic action for fixing tubing in wells with sucker rod pumps, containing a housing with a through longitudinal channel and a hydraulic chamber connected to it with fixing elements triggered by a pressure drop, characterized in that an elastic element is used as fixing elements inflatable packer or radial piston rams, spring-loaded by a return spring, and the hydraulic chamber is connected to the tubing cavity by a tube through a channel in the upper part of the body and is isolated from the longitudinal through channel of the body. 2. An anchor of hydraulic action for fixing tubing in wells with sucker rod pumps according to claim 1, characterized in that a barrel is installed in the anchor body with piston rams, isolating the communication between the hydraulic chamber and the longitudinal through channel of the body. 3. An anchor of hydraulic action for fixing tubing in wells with sucker rod pumps according to claim 1, characterized in that the tube connecting the tubing cavity with the hydraulic chamber is equipped with a spring-loaded check valve with a locking element and a device for forced communication with the tubing cavity. 4. An anchor of hydraulic action for fixing tubing in wells with sucker rod pumps according to claim 3, characterized in that the device for forced communication is made in the form of a sliding sleeve, limited by stops and closing the hole in the tubing and interacting with a counterpart installed on barbells.

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