RU2534876C1 - Double-packer installation for operation of well with electrically driven pump, simultaneous isolation of untight interval and circulation valve - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: double-packer pump unit includes a pipe string of a lesser diameter placed concentrically or eccentrically in a pipe string of a larger diameter. The pipe string of the larger diameter is equipped with the lower and upper packers with a cable input mounted over an electrically driven pump and a return valve. Below the lower packer and over the upper packer the lower criss-cross flow coupling, the lower drain valve and the upper criss-cross flow coupling, the upper drain valve are installed respectively. A control cable, for example, a fibreglass cable, may be laid along the whole equipment and through the packers. A circulation valve and a balancing valve are installed between the lower and upper packers. Above the drain valve the double-packer pump unit is equipped with a disconnector with a hydraulic anchor mounted above it.

EFFECT: improved operational efficiency of the unit and increased reliability of the circulation valve.

4 cl, 4 dwg

Description

The invention relates to the oil and gas industry and can be used for the production of formation fluid using an electric drive pump, in particular in wells with impaired tightness of the production string.

Known borehole packer installation with a pump (options), including a pump lowered into a borehole on a pipe string of constant or variable diameter, and a packer dividing the insulated interval from the bottom of the pump intake and made with or without cable entry. Option 1 contains an additional packer dividing the insulated interval above the annulus, and two bypass devices. A smaller diameter pipe is lowered inside the pipe string and is hermetically connected to the bypass devices. In the second installation option, a string of pipes of a smaller diameter is lowered into the pipe string, hermetically connected with the lower end to the transfer device, and the upper end to the wellhead equipment. Option 3 of the installation is equipped with an additional packer dividing the insulated interval above the annulus. The packers are configured to pass through them an external eccentric pipe of smaller diameter to bypass the medium from the lower sub-packer to the upper super-packer annulus. Installation option 4 includes an additional packer dividing the insulated interval above the annulus. Both packers are double-barreled. Installation option 5 comprises an inkjet apparatus mounted above the pump with a receiving chamber and a pipe of a smaller diameter placed in the pipe string. Option 6 of the installation is equipped with a packer installed below the pump on the shank or on a previously lowered additional lower pipe string with a disconnector at its upper end (RF patent No. 2331758, publ. 08/20/2008).

A disadvantage of the known packer installation is that the bypass circulation valve installed between the packers is placed in the borehole chamber, which leads to an increase in the complexity and cost of the valve removal operation, since it is necessary to use cable technology with the involvement of the cable contractor. Also, this installation does not allow to assess the tightness of the packers during installation and during installation.

A known embodiment of the cross-flow coupling in FIGS. 7, 9 (RF patent No. 2328590, publ. 10.07.2008).

A disadvantage of the known cross-flow clutch is the small size of the eccentric longitudinal through channel, due to which the clutch is able to pass through itself small volumes of produced reservoir fluid. Also disadvantages include the fact that the cross-flow coupling does not have a groove for passing the cable of the submersible motor.

Known circulation valve containing a housing with axial and radial channels for communicating the annulus with the cavity of the drill pipe. Inside the housing there is a hollow differential piston sealed above and below the radial channels by O-rings. The piston is fixed in the housing by calibrated shear pins. From above, a thrust nut is screwed into the valve body until it stops in the upper end of the piston. A spring is put on the piston shank, compressed between the ledge of the valve body on top and the washer resting against the nut (copyright certificate No. 309115, published on July 9, 1971).

The disadvantage of this valve is the design complexity, as well as the possibility that the spring may not work, therefore, the message of the annular space with the cavity of the drill pipe will not be organized.

The technical result of the claimed invention is to ensure easy, trouble-free installation of the installation to the surface after completion of work or, if necessary, changing underground equipment, reducing the complexity and cost of work, increasing oil production, ensuring cable laying through cross-flow couplings and the possibility of real-time monitoring of the tightness of a two-packer installation , providing the ability to keep the packer and other downhole equipment from moving upward when creating a re pressure drop in tubing, simplifying the design of the circulation valve, ensuring its reliable operation.

The claimed technical result is achieved by the fact that:

- the installation is equipped with knock-off valves of the mechanical principle of operation, a circulation valve with shear pins of the hydraulic principle of operation and the equalizing valve, and the knocking valves are located respectively under the lower and upper packers, the circulation and equalizing valves are installed in series between the packers;

- the eccentric through longitudinal channel of the cross-flow coupler is made of an expanded C-shape, and in the body of the cross-flow couplers in a direction parallel to the axis of the couplers, a longitudinal groove for cable laying is made;

- the installation is equipped with a control cable, for example, fiber optic;

- the installation is equipped in the upper part above the disconnector with a hydraulic anchor;

- a cap is installed in the upper part of the circulation valve body, fixed from axial movements by shear screws, and a nut is installed in the lower part of the body, fixed from the flap by a screw, while there is a set of seals between the body and the cap.

Equipping the installation with mechanical operating principle by flapper valves, a circulation valve with hydraulic operating shear pins and equalizing valve, as well as setting the flap valve under the lower and upper packers, respectively, installing the circulation and equalizing valves in series between the packers will allow easy, trouble-free installation of the unit to the surface after completion of work or, if necessary, a change of underground equipment.

The implementation of an eccentric through longitudinal channel of the cross-flow coupling of the expanded C-shaped shape will increase oil production.

The execution of the longitudinal groove for laying the cable in the housing of cross-flow couplings in a direction parallel to the axis of the couplings will allow for cable routing through cross-flow couplings.

Equipping the installation with a control cable, for example, fiber optic, will allow real-time monitoring of the tightness of the two-packer installation.

Equipping the installation in the upper part above the disconnector with a hydraulic anchor will keep the packer and other downhole equipment from moving upward when creating a pressure drop in the tubing.

The installation of a cap fixed in the upper part of the circulating valve body, fixed from axial movements by shear screws, and a nut fixed in the lower part of the casing of the screw from the flap, as well as installing a set of seals between the casing and the cap, will simplify the design of the circulation valve and ensure its reliable operation.

Figure 1 presents a diagram of a two-pack pumping unit. Figure 2 presents a diagram of the cross-flow coupling. Figure 3 shows a section aa cross-flow coupling. Figure 4 shows a diagram of a circulation valve.

The two-packer pump installation includes a pipe string of a smaller diameter 1, placed concentrically or eccentrically in a pipe string of a larger diameter 2. A pipe string of smaller diameter 1 is hermetically seated at the bottom and top, respectively, in the lower 3 and upper 4 cross-flow couplings. The pipe string of larger diameter 2 is equipped with a lower 5 and an upper 6 packer with a cable entry located above the electric drive pump 7 and a check valve 8. The packers 5, 6 are designed to isolate the leakage interval of the production string or formation 9. The first interval with the annular one is formed above the upper packer 6 pressure P _s . ₁ and in- _pipe pressure P _tr . ₁ . Between the packers 5, 6, a second interval is formed with the _annular pressure P _s . ₂ and the in- _pipe pressure P _tr . ₂ . Under the lower packer 5, a third interval is formed with the _annular pressure P _s . ₃ and the in- _pipe pressure P _tr . ₃ .

Under the lower 5 and over the upper 6 packers, the lower cross-flow coupling 3, the lower relief valve 10 and the upper cross-coupling 4 and the upper relief valve 11 are installed respectively. The relief valves 10, 11 are designed to equalize the pressures P _s . ₁ and P _tr, respectively _{. 1} , P _s . ₃ and P _tr . ₃ . Cross-flow couplings 3, 4 are designed to move the flow of produced reservoir fluid and gas discharge. Along all the equipment and through the packers 5, 6, a control cable 12, for example, fiber optic, can be laid.

The cross-flow couplings 3, 4 are made in the form of a housing 13 (FIG. 2) with an eccentric through longitudinal channel 14 for moving the flow of produced reservoir fluid, an axial through channel 15, and a transverse radial channel 16 for venting gas. The eccentric through longitudinal channel 14 is made of an expanded C-shaped (figure 3). In the case of cross-flow couplings 3, 4 in a direction parallel to their axis, a longitudinal groove 17 is made for laying the cable 18 of the electric drive pump 7 and the control cable 12. The groove 17 is configured in such a way that it is possible to work with the range of electric cables produced today .

Between the lower 5 and upper 6 packers installed circulating 19 and equalizing 20 valve. The circulation valve 19 is designed to organize communication annular space and the internal cavity of the pipe string. The circulation valve 19 consists of a housing 21, on which a cap 22 is mounted, fixed from axial movements by shear screws 23. The tightness of the connection of the housing 21 and the cap 22 is provided by a set of seals 24, 25, consisting of protective and sealing rings. A nut 26 is installed on the housing 21, fixed from the top by a screw 27.

The equalizing valve 20 is designed to align the annular pressure P _C.2 with the in- _pipe pressure P _Tr.2 .

The two-packer pumping unit above the shut-off valve 11 is equipped with a disconnector 28. The disconnector 28 is designed to hydraulically disconnect the upper part of the pipe string 2 from the upper packer 6 in case of complications during hoisting operations.

Above the disconnector 28, a hydraulic armature 29 with grooves (not shown in FIG.) Is installed to install the cable 18 and control cable 12. The hydraulic armature 29 serves to hold the packer and other downhole equipment from moving upward while creating a pressure drop in the tubing.

Two-pack pumping unit operates as follows.

To produce formation fluid from a well with leaky production casing 30, the pumping unit is assembled in the following sequence: an electric drive pump 7 is mounted on a pipe string of larger diameter 2, a control cable 12 is attached to the pipe string 2 during descent if there is a need for tightness control packers 5, 6 in real time during the production process, through a predetermined number of pipes, a check valve 8, a relief valve 10, a cross-flow coupling 3, a lower packer with by an abel inlet 5, a circulation valve 19, a balancing valve 20, an upper packer with a cable entry 6, a cross-flow coupling 4, a relief valve 11, a disconnector 28, a hydraulic armature 29.

Lower the pump unit on the pipe string to the design depth. Lower 5 and upper 6 packers are transferred to the working position in a known manner.

The downhole installation is launched. By creating an in-line pressure, the hydraulic armature 29 is actuated (FIG. 1). Under pressure, the dies (not shown in the figures) of the hydraulic armature 29 extend outward in the radial direction and penetrate the walls of the production string 30. The formation fluid passes through the through eccentric holes of the lower 3 and upper 4 cross-flow couplings. Gas is removed through transverse radial channels 16 along the inner cavity of the pipe of smaller diameter 1 from the annulus below the lower packer 5 into the annulus above the upper packer 6.

The control cable 12, if installed, allows you to monitor the tightness of the packers 5, 6 in real time during production.

The tightness control of packers 5, 6 is carried out as follows: the optical fiber of the control cable 12 senses and measures the temperature along the wellbore with a certain interval, for example, one meter, then the measurement information is transmitted through the control cable 12 to the surface where the controller is installed (in the figures shown). If the data of temperature measurements above and below the packer 5 and / or 6 are the same values, then the packers 5 and / or 6 are leaking. If the temperature above and below the packer 5 and / or 6 is different, the tightness of the packers 5 and / or 6 complied with.

At the end of the production process or, if necessary, changing the underground equipment, the pumping unit is hoisted as follows. To create a message between the annulus and the internal cavity of the pipe string 2, pressure is applied to the pipe string 2. When creating a given differential in the pipe string 2 and the annulus, the screws 23 of the circulation valve 19 are cut off (Fig. 4) and a message opens between the cavity of the pipe string 2 and the annulus.

_{Equalize the} pressure P _s.2 and P _Tr.2 , for which they pull the pipe string 2 (Fig. 1) with a force exceeding its weight, while opening the side holes (not shown in the figures) of the equalizing valve body 20 for communicating the annulus with the inner the cavity of the pipe string 2. When pulling the pipe string 2, the lower packer 5 remains stationary, and the upper packer 6 moves up.

Next, the upper knockdown valve 11 is _{mechanically actuated,} and P _p . ₁ and P _tr . 1 are _aligned . When the pressure in the pipes is removed, the dies of the hydraulic armature 29 return to their original position under the action of springs (not shown in the figures), as a result, the hydraulic armature 29 is released.

The upper 6 and lower 5 packers are moved to the transport position. After transferring the packers 5, 6 to the transport position and dismantling the lower cross-flow coupling 3, the lower knockdown valve 10 is _{mechanically actuated,} and P _p . ₃ and P _tr . _{3 are aligned} . Next, the installation is lifted from the well.

In case of complications during installation lifting, the upper part of the pipe string 2 is disconnected from the upper packer 6 hydraulically using a disconnector 28. Further extraction of the installation is carried out with a standard fishing tool (not shown in the figures).

The application of the claimed invention will allow for easy, trouble-free installation of the installation to the surface after completion of work or, if necessary, changing the underground equipment, reducing the complexity and cost of work, increasing oil production, ensuring cable laying through cross-flow couplings, as well as the possibility of real-time monitoring of two-packer tightness installation, to provide the ability to hold the packer and other downhole equipment from moving upward when creating a pressure drop in tubing, simplify the design of the circulation valve, ensure reliable operation of the circulation valve.

Claims (4)

1. A two-packer installation for operating wells with an electric drive pump with simultaneous isolation of the leakage interval, including two columns of pipes of larger and smaller diameters sequentially deflated and installed in the well, placed concentrically or eccentrically in one another, two packers with cable entry, isolating the leakage interval, two bypass devices located respectively below and above the packers and hermetically connected to the pipe string of smaller diameter, the cavity between the pipe string and pipe a smaller diameter, hydraulically connected to the pipe string cavities below and above the bypass devices for producing fluid through their eccentric through longitudinal channels, as well as an internal cavity of a smaller pipe string, hydraulically connected to the spaces above and below the packers through the transverse radial channels for gas bypass , disconnector, bypass circulation valve, characterized in that it is equipped with knock-off valves of a mechanical principle of operation, a circulation valve with shear pins hydraulic principle of operation and equalizing valve, with knocking valves located respectively under the lower and above the upper packers, the circulation and equalizing valves are installed sequentially between the packers, the eccentric through longitudinal channel of the cross-flow coupling is made of an expanded C-shape, and in the cross-flow coupling housing In the direction parallel to the axis of the couplings, a longitudinal groove is made for laying the cable. 2. Installation according to claim 1, characterized in that it is equipped with a control cable, for example, fiber optic. 3. Installation according to claim 1, characterized in that it is equipped in the upper part above the disconnector with a hydraulic anchor. 4. A circulation valve including a housing, seals, characterized in that a cap is installed in the upper part of the casing, fixed from axial movements by shear screws, and a nut is fixed in the lower part of the casing, fixed from the flap by a screw, while there is a set of seals between the casing and the cap .

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