RU1809026C - Device for well electric equipment switching-on - Google Patents

Abstract

Purpose: the invention relates to the oil industry and is intended to supply electrical energy to electrical equipment located in a well. SUMMARY OF THE INVENTION: An elastic cassette filled with an electrically insulating fluid is lowered into a well on a tubing inside which a contact floor fork is mounted. A cassette is installed on the casing, in which a socket is mounted connected to the supply cable. When the plug enters the socket, the cartridge in which the plug is located is compressed, and the insulating fluid, squeezed out through the inner cavity of the plug, fills the capacity of the socket cassette, displacing the borehole fluid from it, the density of which is less than the density of the insulating fluid. To prevent leakage of electrically insulating fluid into the well, a non-return valve is installed in the bottom of the elastic cassette, and to protect the cavity of the cassette with the socket from ingress of foreign matter located in the borehole fluid, the cassette lid has spring-loaded shutters opening inside the cassette. 5 ill. ate

Description

The invention relates to the oil industry, and more specifically to the construction and equipment of oil wells, as well as to devices used in their operation.

The purpose of the invention is to increase the reliability of the inclusion of electrical equipment in the well.

In order to achieve the intended purpose, it is proposed, during the construction of the well, to install inside the casing a socket having three phases and connected to an electric cable located behind the casing.

A plug must be connected to this outlet for operating the well, which in turn must be connected

with downhole equipment consuming electric current.

In order to ensure reliability, the inclusion of downhole equipment, it is proposed that this inclusion be performed in a special device filled with an insulating fluid, immiscible with the downhole fluid and having a higher density than the density of the downhole fluid.

Before putting the well into operation, the plug on the surface is completed in one unit with electrical equipment (e.g., electric pump), as well as a container in which the required amount of electrical insulating fluid is transported into the well. The fork is mounted

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inside this cassette container filled with electrical insulating fluid. When the plug enters the socket, the capacity of the plug cassette is squeezed and the insulating fluid is squeezed from the plug cassette into the receptacle. As a result, the capacity of the outlet cassette is filled with electrical insulating fluid, ensuring reliable inclusion of electrical equipment in the well.

In FIG. 1 shows a diagram of the inclusion of one of the phases of the device in three static positions a, b, c:

in position a, the upper cassette is shown with the plug located above the lower cassette with a socket.

in position b, the same cassettes are shown after the upper cassette has lowered and the plug has started connecting to the outlet. In position c, the device is shown when the plug is electrically connected to the outlet, and the electrically insulating fluid is completely extruded from the upper cassette into the lower one.

In FIG. 1, the individual parts of the device are shown only for the static position a, since the arrangement of these parts for the positions of the beams is evident from the drawing, despite their displacement.

As can be seen from the drawing, the upper cassette

1 has a lid 2 on top and a bottom 3 on the bottom. The lid is connected to the bottom c. by means of an elastic, corrugated wall 4. Inside the cassette there is a contact plug 5, of the floor from the inside. This plug is attached to the lid.

2 and electrically connected by an electrical conductor 6 to electrical consuming downhole equipment. The cassette contains electrically insulating liquid 7.

In the upper part of the plug there are through holes 8 communicating the cavity of the cartridge with the cavity of the plug. In the lower part, the plug cavity is closed by a valve 9 supported by a spring 10. The cartridge is provided with cuffs 11 which seal the gaps between the fork and the bottom of the cartridge. The lower cassette is a cup 12, consisting of an upper cover 13, side walls 14 and a bottom 15. Inside this cassette is a socket 16 consisting of two halves: 17 and 18, pressed against each other by a spring 19. The cover of the lower cassette is provided Sashes 20 opening into the cassette, tightly pressed against each other by springs 21. An insulated electric cable 22 is electrically connected to the socket 16. The outer end of this cable is connected to the corresponding phase of the outer cable 23 located behind the casing through the bottom of the lower cassette onnoy 24.

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In FIG. Figure 2 shows that bottom in the structure of the well, below the casing 24. Casing 25 is located. It has a smaller diameter than Casing 24. The lower cassette 12 is located on the site formed in the borehole as a result of a change in the diameter of the casing.

In FIG. Figure 2 shows the position of the device upon delivery from the surface on the tubing string 27 of the cartridge cassette, as well as electrical insulating fluid into the well. This cassette is lowered in one unit with electrical equipment.

In FIG. 2 shows that the outer cable 23 is in the borehole inside the cement stone 26,

In FIG. 3 - section of the well along AA.

It can be seen here that the switching sockets 0 of the various phases have an arched shape and different lengths. Three cassettes with forks have similar shapes and sizes, ensuring the inclusion of the corresponding phases when oriented downhill them on 5 tubing into the well.

The operation of the device is as follows.

During well construction, a casing string is lowered into it. Together with it, an electric cable is lowered into the well, which is located behind the casing and is intended to supply electricity to the well, to operate various equipment in it: electric pumps, electric heaters, etc.

The depth of the well to which electricity is to be supplied is set in advance, prior to the start of the well drilling. Based on the operating conditions, the well design is also determined. The invention contemplates a stepped well design to reduce the diameter of the casing. In those places where it is intended to install and turn on 5 power-consuming equipment.

Fig. 2 shows the installation of a cassette with a socket on a site formed by reducing the diameter of the casing. This installation, as well as the electrical connection of the outlet with an electric cable behind the string, should be carried out during the construction of the well. After the casing has been lowered, it is cemented and the cable located behind the casing is inside the cement stone. When the construction of the well is completed and the influx of production from the formation into the well has been achieved, and the required fluid level provided for by the forecast has been established in the well, the corresponding

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electrical equipment. This electrical equipment is completed in a single unit (delivery block), including a plug located in the upper cartridge 1. In this case, the upper cartridge is filled with insulating liquid 7. At the same time, the cavity of the plug 5. is also filled with the same liquid. the period of descent into the well is maintained due to the presence in the lower part of the plug cavity of the valve 9, which is kept closed by the spring 10. When the pump and compressor pipes 27 together with the delivery unit transported to them are lowered enes to the stop of the cover 13 and the lower cassette will plug the entry into a socket, disengagement t derivative pump-compressor weed pipes from delivery unit and lift them to the surface. To turn the electrical equipment in the well into operation, a cable 23 is connected to the surface to a current source (not shown). Electricity through the cable 23, the socket 16 and the plug 5 through the conductor 6 is supplied to the power-consuming equipment and turns it on.

The circuits shown in FIG. 1 illustrate the positions of the included elements of only one of the three phases. The position of the included structural elements of the other two phases is similar. Therefore, they are not represented in individual figures. The inclusion of the three phases of the device occurs simultaneously, because in the delivery unit of the three-phase plug, there are located a circle around the circle, and under them there are respectively three sockets (Fig. 3). The process of plugging the plug into the socket shown in Fig. 1 consists of three stages of its implementation. The first stage includes transporting the delivery unit in the well.

As noted, an upper cassette is lowered into the well at this stage, with a plug and electrically insulating fluid. To prevent leakage of electrical insulating fluid into the well, cuffs 11 and a check valve 9 are provided in the upper cassette. The second stage includes the process of plugging in the socket. A distinctive feature of this step is the overflow from the upper cassette of the electrically insulating fluid delivery unit to the lower cassette. The second step is carried out as follows. At the end of the descent of the delivery unit into the well, when the bottom delivery unit of the cassette 3 starts to abut against the ceiling 13 of the lower cassette, the upper cassette of the delivery unit begins to compress and decrease in volume as a result of compression of its elastic walls. When capacity decreases

the upper cassette begins to increase the pressure on the insulating liquid in the container. Under the influence of this pressure, the electrically insulating fluid begins to flow through the opening 8 into the cavity of the plug. The electrically insulating fluid located there, in turn, begins to exert pressure on valve 9. The spring 10, which holds it closed 0, stretches, the valve opens and the electrically insulating fluid from the upper cassette of the delivery unit begins to fill the lower cassette. This implementation phase of the device is shown in FIG. 1 in position b. Here, it should be noted that in FIG. In position 1, flaps 20 supported by spring 21 are shown on cover 13 of lower cassette. These flaps are designed to protect

0 cavity of the lower cartridge from the ingress of individual inclusions from the well fluid. The flaps 20 open and remain open after the lower end of the plug opens them when the plug moves toward the outlet.

5 In FIG. 1, in the beam positions, for simplicity, the sash 20 and spring 21 are not shown,

During the period of overflow of electrically insulating fluid from the upper cassette to the lower one, the latter can be completely or partially filled with the borehole fluid. In order for the electrically insulating liquid to completely fill the lower cassette, it is necessary that it is replaced in the cassette

5 borehole fluid, therefore, it is necessary that the electrically insulating fluid have a density higher than the density of the borehole fluid. It is obvious that the electrically insulating fluid must also be chemically neutral to the borehole

liquids. To displace

borehole fluid from the lower cassette

the design provides for

 top of bottom reverse cassette

5 valves. This valve is in construction, but in FIG. 1 is not shown. The third stage of the implementation of the introduction of the device is carried out after filling the lower cassette with electrical insulating liquid and

0 full plug in the socket. Then, on the surface, an electric current is connected to the cable 23, which, through the conductor 22, is supplied to the outlet, from it to the plug, and then to the power-consuming equipment.

5 launched into the well in one delivery unit with a plug and electrically connected to it.

The present invention can be used in the well repeatedly. For example, if necessary,

well of geotechnical work, the device can be raised to the surface. To do this, pump and compressor pipes are lowered into the well. A trap is located at the lower end of these pipes to catch the delivery unit installed in the well. After the catcher engages with the delivery unit, the tubing string rises entraining the delivery unit. Equipment is pulled to the surface. After the necessary repair of the well has been carried out, previously raised equipment is again lowered into it.

An example of a specific use.

We have a well with a depth of 1,500 m. The well is vertical. Cased from above to a depth of 1000 m by casing (dimensions in mm), and from below by the casing. The cement ring has a thickness on the upper interval (, on the lower, In the cement stone on the upper interval there is an electric cable. The well filter is at a depth of 1450-1500 m. At a depth of 1000 m, at the transition point of the casing from to, a lower cassette with a socket is installed.

An example of use is illustrated in FIG. 4 and FIG. 5.

In FIG. 4 shows a lower cassette device, and FIG. 5 shows the same cassette when the plug of the delivery unit came into contact with the outlet. A lock for engaging a delivery unit with a tubing string for implementing Ј,

transporting and removing the delivery unit to the well in FIG. 5 .che shown. Referring to FIG. 4 and FIG. 5 sizes, 5, and diameter.

FORMULA AND SECTION

A device for turning on electrical equipment in a well equipped with a casing stepped string, comprising a lower cassette fixed rigidly on the annular area of the string, made in the form of a cup filled with a borehole with liquid, in which there is a socket connected to the power cable and filled with electrical insulation liquid with a higher density borehole fluid, an upper cassette in which a contact plug is arranged, characterized in that, in order to increase the reliability of the contact connection, the upper cassette is made with elastic walls and provided with a cover made of electrical insulation material, to which a plug is attached from below, and is electrically connected to electrical consuming downhole equipment,

wherein the plug is hollow, through holes are made in the upper part of the walls of the fork for communicating the cavities of the cartridge and the fork, a check valve is located in its lower part, and plug holes are made in the bottom of the cartridge, the lower cartridge being provided with a lid with spring-loaded shutters opening into the cartridge, and the outlet is made of two halves, spring-loaded to each other.