RU216475U1 - DEVICE FOR HYDRODYNAMIC STUDIES OF A WELL - Google Patents

Abstract

The utility model relates to the field of mining and can be used in the oil and gas industry for hydrodynamic studies of a well in a tubing string. The device comprises sealed upper (1) and lower (16) housings lowered on a geophysical cable (2) into the tubing string (3). In the housing (1) there is an electric motor (4), a switching unit (5), a planetary gearbox (6), a screw gear, with a nut (8) of which a rod (9) is connected, which interacts with the pusher (10). A packer (11) and an anchor consisting of wedge slips (12) and an expander (13) are installed above the pusher (10). The balancing valve contains a piston (15), which, during axial movement in the chamber (14), interacts with the flow holes (10.1) of the pusher (10). An instrument head (19) is installed in the upper part of the device, connected to a geophysical cable (2) using a cable lug (20). In the lower housing (16) there is a tool tip (23) for docking through the tool head (24) with a remote downhole tool (25) and connecting the tool (25) to the transit wire (22). Switching unit (5) contains upper and lower limit switches (5.1) with contact buttons, flat springs (5.2) and stroke limiter (5.3) connected to rod (9). Limit switches (5.1) are installed along the axis of the device at a mutual distance from each other from 30 mm to 70 mm, which makes it possible to conduct studies in tubing strings with a range of pipe inner diameters from 58 mm to 64 mm. The technical result is to increase the versatility of the device for hydrodynamic studies of the well. 2 w.p. f-ly, 5 ill.

Description

The utility model relates to the field of mining and can be used in the oil and gas industry to monitor well processes during hydrodynamic testing of a well (well test) in a tubing string (tubing) by measuring the hydrodynamic parameters of the formation.

A device for hydrodynamic monitoring of wells is known, which contains a sealed housing lowered into a tubing string on a geophysical cable, in which an electric motor and a switching unit are located, connected to the electric motor by means of a screw transmission, a rod that transmits the load to the packer, an anchor installed above the packer as part of the wedge rams and wedge dies expander, balancing valve, two pressure compensators, one of which is installed above the anchor, and the second one is installed below the balancing valve, cable head tip in the lower part of the device and remote downhole tool attached to the cable head tip (see RU 2471984 C2 , published 01/10/2013).

The technical problem of the known device is the inability to configure the device for research in tubing with an inner diameter that deviates from the value specified by the standard. In cases where the tubing wall thickness differs from the nominal value due to the effect of corrosion or poor-quality preparation of tubing for research, insufficiently reliable engagement of anchor slips on the inner walls of the pipes may occur during monitoring. As a result, the device is displaced from the installation site along the tubing string, leaky overlapping of the internal cavity of the tubing, which leads to a distortion of the results of studies of well processes.

The technical result of the utility model is to increase the versatility of the device for hydrodynamic studies of a well.

A technical result is achieved due to the fact that in a device for hydrodynamic studies of a well, containing a sealed housing lowered into the tubing string on a geophysical cable, in which an electric motor and a switching unit are located, a rod connected to the electric motor by means of a screw gear and interacting with the packer, an anchor installed above the packer, a balancing valve, pressure compensators, a cable head tip and a remote downhole tool attached to the cable head tip in the lower part of the device, according to the utility model, the switching unit contains limit switches with contact buttons located along the device axis at a mutual distance L, springs interacting with the contact buttons of the limit switches, a travel limiter mounted for movement along the axis of the device and connected to the stem.

In particular implementation cases, the distance L is measured between the contact buttons of the limit switches of the switching unit; the distance L is between 30 mm and 70 mm.

The device for hydrodynamic studies of a well is illustrated by drawings, which show:

in fig. 1 - device in transport condition, longitudinal section;

in fig. 2 - section A-A in Fig. 1;

in fig. 3 - view B in Fig. 2;

in fig. 4 - device in working order during well testing, longitudinal section;

in fig. 5 - the device in the state after well testing and return to the transport state, longitudinal section.

The device for hydrodynamic studies of the well (Fig. 1) contains a sealed upper housing 1, which is lowered on a geophysical cable 2 into the tubing string 3. In the housing 1, an electric motor 4, a switching unit 5 (Fig. 2, 3), a planetary gearbox 6, a screw a gear consisting of a lead screw 7 and a nut 8. A rod 9 is connected to the nut 8 of the screw gear. The rod 9 consists of several parts connected in series and in its lower part is made with an annular stop 9.1, with which it interacts with the pusher 10.

A packer 11 with rubber cuffs is installed above the pusher 10 as a packer element. Directly above the packer 11, there is an anchor consisting of wedge slips 12 and wedge slip expander 13, with which the rubber cuffs of the packer 11 interact. By means of the rod 9 and the pusher 10, the load from the electric motor 4 is transferred to the packer 11 for remote control of the overlap of the inner diameter of the tubing.

In the walls of the pusher 10, through flow holes 10.1 are made, which are elements of the equalizing valve, which is equipped inside the body of the pusher 10. The equalizing valve contains a piston 15 installed in the chamber 14, which, during axial movement, interacts with the flow holes 10.1 of the pusher 10.

The lower part of the pusher 10 is connected to the sealed lower housing 16.

The device is equipped with two pressure compensators designed to balance the hydraulic pressure of the liquid column acting on the rod 9 in the process of conducting hydrodynamic studies. The upper pressure compensator 17 is located above the anchor, the lower pressure compensator 18 is located in the lower housing 16 under the equalizing valve.

In the upper part of the device, a standard instrument head 19 is installed, which is mechanically and electrically connected to the geophysical cable 2 using a standard cable lug 20. In the instrument head 19, the wires of the geophysical cable 2 are contacted with the electrical wires 21 of the electric motor 3 and the wires of the transit wire 22. In the lower part of the device, inside the lower housing 16, a tool tip 23 is installed for mechanical docking through a standard tool head 24 with a remote downhole multi-parameter geophysical tool 25 and for electrical connection of a remote downhole tool 25 with a transit wire 22.

The switching unit 5 (Fig. 2, 3) contains the upper and lower limit switches 5.1 with contact buttons, two springs 5.2 and a stroke limiter 5.3. The upper and lower limit switches 5.1 are installed along the longitudinal axis of the device at a mutual distance L from each other, which can be from 30 mm to 70 mm. The distance L is measured between the contact buttons of the limit switches 5.1. Each of the limit switches 5.1 can be moved and fixed within the distance L inside the housing of the switching unit 5. Flat springs are used as springs 5.2 for contact interaction with the contact buttons of the limit switches 5.1. The travel stop 5.3 is installed with the possibility of axial movement along the longitudinal groove made in the body of the switching unit 5 for contact interaction with the springs 5.2. The stroke limiter 5.3 is connected to the upper part of the stem 9.

After a small preliminary adjustment, carried out in the switching unit 5 on the surface of the well before well testing, the device is able to work in any tubing with a diameter of 73 mm. In accordance with GOST 633-80 “Tubing pipes and couplings for them. Specifications”, tubing 73 with a wall thickness of 5.5 mm and 7.0 mm is used. The inner diameter of the pipe is 59 mm and 62 mm, respectively. The standard allows a change in diameter within ± 0.8 mm, from which it follows that situations are possible when the inner diameter of the pipe can be from 58.2 mm to 62.7 mm. Thus, the use of the device of the proposed design, which includes a switching unit 5 with two limit switches 5.1, makes it possible to conduct research in tubing strings with a range of changes in the inner diameter of the pipe from 58 mm to 64 mm. By expanding the possibility of using pipes with an internal diameter in the specified range of values, an increase in the versatility of the device for hydrodynamic studies of wells is achieved. Adjusting the distance between the limit switches 5.1 in the switching unit 5 sets the value of the stroke of the rod 9, which most closely matches the actual inner diameter of the investigated tubing, which increases the reliability of engagement of the wedge dies 12 of the anchor for the inner walls of the tubing, reduces the likelihood of axial displacement of the device along the tubing string, improves tightness of the overlap of the tubing cavity.

The distance L between the contact buttons of the limit switches 5.1 in the switching unit 5, corresponding to the value of the stroke of the rod 9, is determined by the following relationship:

where D1 - inner diameter of tubing 73;

D2 is the diameter of the rubber cuffs of the packer;

tg a - the angle of inclination of the wedge dies;

k - packer reliability factor, determined empirically (usually varies within 1.2-1.25).

Device for hydrodynamic studies of wells operates as follows.

Before lowering the device into the well, using the switching unit 5, the interval of the working stroke of the rod 9 is adjusted taking into account the value of the inner diameter of the pipe in the research interval. To do this, limit switches 5.1 are placed in the openings of the switching unit 5 at a distance L from each other, calculated from the specified ratio.

After creating a drawdown on the formation, the assembly of the device, including the remote downhole tool 25, is lowered inside the tubing string 3. The descent is carried out using a geophysical cable 2 wound on the winch drum of a geophysical lift and docked with the tool head 19 by means of a cable lug 20.

During the descent, the device is in the idle (transport) position, in which the packer 11 is closed (Fig. 1). The equalizing valve is closed, the piston 15 closes the flow holes 10.1 of the pusher 10. The upper pressure РВ _of the fluid in the above-packer space and the lower pressure Рн of the liquid in the under-packer space are the same in value, Рv=Рн.

When the research interval is reached, the device is fixed inside the tubing string and the inner diameter of the tubing is covered. To do this, voltage is supplied from the wellhead through electric wires 21 to the electric motor 4. The planetary gear 6 converts the torque of the electric motor 4 into the translational movement of the nut 8 of the screw transmission, to which the rod 9 is connected, as a result of which the rod 9 starts moving up.

Between the upper housing 1 and the lower housing 16, the distance is reduced to a limit, which is determined by the operation of the upper limit switch 5.1 of the switching unit 5. The power circuit is interrupted by the spring 5.2, which is pressed by the stroke limiter 5.3 connected to the stem 9.

In the process of moving the rod 9, the expander 13 expands the wedge dies 12 with its cone, they diverge until they stop against the inner walls of the tubing 3, fixing the device from axial movement. At the same time, the rod 9 with the annular stop 9.1 moves the pusher 10 upwards through the body of the lower pressure compensator 18. Under the action of the pusher 10, the rubber cuffs of the packer 11 are compressed, increase in diameter and hermetically block the flow area of the tubing 3. The equalizing valve remains closed, the piston 15 closes the flow holes 10.1 pushers 10.

The opening of the packer 11 blocks the inflow of fluid into the well, as a result of which the lower pressure Pf of the fluid in the sub-packer space, below the isolated interval, increases and begins to exceed the upper pressure Pv of the fluid, Pv<Pn (Fig. 4). At this stage, the remote downhole tool 25 records the formation pressure recovery curve over time in the under-packer space. The proposed design of the device makes it possible to build a formation pressure recovery curve without distortion and determine the true hydrodynamic parameters of the formation. Through the transit wire 22, along the geophysical cable 2, the received operational data is transmitted to the surface, on the basis of which a decision is made to continue work to cause inflow from the reservoir, or to stop work, or to carry out measures to lower the production pump, or to influence the bottomhole part of the reservoir in order to intensify the flow.

After the completion of measurements and data transfer, unpacking is performed. To do this, the electric motor 4 is supplied from the wellhead voltage of reverse polarity. Rod 9 starts to move down. The movement of the rod 9 occurs until the lower limit switch 5.2 is actuated.

As long as there is an excess of pressure Pn in the space under the packer over the pressure Pb above the packer 11, the rubber cuffs of the packer 11 do not return to their original state. The rod 9, moving down inside the equalizing valve chamber 14 together with the piston 15, opens the flow holes 10.1 of the pusher 10. After the equalizing valve is opened, the excess pressure under the packer 11 is instantly released, the pressure pulse due to hydraulic imbalance with the open flow holes 10.1 acts on the pusher 10 , releasing the rubber cuffs of the packer 11 from contact with the inner wall of the tubing, the fluid flows from the under-packer space through the flow holes 10.1 of the pusher 10 into the over-packer space. The pressures of the upper Рv and the lower Рn are aligned, Рv=Рn (Fig. 5).

The return of the rod 9 to the lowest position before the lower limit switch 5.2 is actuated causes the expander 13 to move down. The rod 9 descends from under the wedge dies 12. The wedge dies 12 fold and disengage from the walls of the tubing 3.

To bring the device into the transport position, it is necessary to remove the residual stress of the rubber cuffs of the packer 11 by pulling the geophysical cable 2 by winding it on the winch drum of the geophysical lift. The slow lifting of the device from the well leads to the fact that the rubber cuffs of the packer 11 finally go into the closed state. The pusher 10, with a fixed rod 9 and piston 15, closes the flow holes 10.1, as a result of which the equalizing valve closes.

After returning the device to its original transport state (see Fig. 1), it is ready for complete extraction from the well.

Claims (3)

1. A device for hydrodynamic studies of a well, containing a sealed housing lowered into a tubing string on a geophysical cable, in which an electric motor and a switching unit are located, a rod connected to the electric motor by means of a screw transmission and interacting with a packer, an anchor installed above the packer, equalizing valve, pressure compensators, a cable head tip and a remote downhole tool attached to the cable head tip in the lower part of the device, characterized in that the switching unit contains limit switches with contact buttons located along the device axis at a mutual distance L, springs interacting with contact limit switch buttons, stroke limiter mounted for movement along the axis of the device and connected to the rod. 2. A device for hydrodynamic studies of a well according to claim 1, characterized in that the distance L is measured between the contact buttons of the limit switches of the switching unit. 3. A device for hydrodynamic studies of a well according to claim 1, characterized in that the distance L is from 30 mm to 70 mm.

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