RU2232889C1 - Electrical separator for well telesystems - Google Patents

Abstract

FIELD: well drilling technology.

SUBSTANCE: device has combined, consisting of at least two parts metallic body with channel and connecting threads on ends. On outer cylindrical surface along length of body and in channel electro-insulating coverings are made. In threaded conical engagement of body parts electro-insulator is provided. One of body parts is made stepped, with a shelf and cylindrical portion with diameter lesser than body, on end of this portion a nipple thread is made for engagement with second part of body. Reactive sleeve end of the latter is made with slanted shear. On cylindrical portion of first part additional insulator in form of bushing with slanting shears of ends and fixing bushing are placed. Additional insulator is made metallic inside, and along its whole surface a layer of highly hard dielectric is formed. Fixing bushing on the side of additional insulator is mad with slanting shear reactive to it, and its other end is rigidly, by welding, for example, is connected to body of first part.

EFFECT: reliable protection of one body part from angular displacement relatively to the other part, and higher durability and overall reliability.

2 dwg

Description

The invention relates to elements of downhole telesystems designed to monitor and control the drilling of deviated wells, complex wells and horizontal wells.

Currently used borehole telesystems with a wireless electromagnetic data transmission channel use an electric separator (dipole) as a transmitting antenna, which is an insulator insert with an electrically insulated outer and inner surfaces in the drill pipe string, i.e. the ends of this insert are electrically disconnected. When an electric impulse is applied to them, the signal from one side along the upper part of the drill string, and from the other side through the rock reaches the surface where it is recorded by ground receiving equipment.

Known electrical separator [1], which is an insulator insert for the formation of a deep dipole antenna with the aim of connecting to it a transmitting generator of a downhole telesystem for wireless transmission of electromagnetic signals to the surface of the channel through the drill pipe string - rock channel.

Also known is the electric separator [2] of the drill pipe string, which is included as part of the downhole (downhole) ZIS-4 telesystem (developed by VNIIGIS, Bashkortostan, Oktyabrsky, 1983). The electrical separator is a composite structure containing a metal case and connecting threads at its ends (for screwing it with other elements of the tele-system), a dielectric coating of the threaded joint (connection) of its parts (in the middle part of the case), as well as a section with a dielectric coating of its outer surface and the dielectric inner coating in the form of a dielectric tube insert flush with the inner surface of the channel.

The closest technical solution, otherwise the prototype, adopted an electric separator [3] drill pipe string, including the upper and lower parts of the housing connected by a conical threaded section with a dielectric coating and cylindrical layers of electrical insulation material on the outer and inner surfaces.

As shown by the rather long practice of geophysical services for operating a well-known object, simultaneously used as a housing for placing a borehole (deep) telemetry system and as a radiating dipole antenna, it is quite functional, but only when using a downhole drive of a rock cutting tool without intensive rotation of the drill string . Attempts to use this design during rotary drilling of a well or frequent turning of the drill string in the wellbore (during turbine drilling) dramatically reduce the service life of the electric separator as a radiating dipole antenna due to damage or complete destruction of the dielectric material through a threaded joint with an insulator insert, joint its parts due to imperfection of fixing parts of the housing from mutual angular displacement and (or) unscrewing.

The required technical result, otherwise, the goal of creating the inventive design of an electric separator for downhole tele-systems as a radiating antenna is to provide reliable protection against the angular displacement of one part of the body relative to another, otherwise to provide enhanced consumer properties, such as durability, reliability, maintainability, and without complication technology and increased manufacturing costs.

The goal (otherwise, the required technical result) is achieved by the fact that in the well-known electrical separator for downhole telesystems, containing a composite, consisting of at least two parts, a metal housing with a channel and connecting threads at the ends, an insulating coating of part of the outer cylindrical surface along the length housing, a similar coating of its channel, an insulator in a threaded conical joint of housing parts, one of the parts of the latter is made stepwise, with a ledge and a cylinder There is a nipple thread at the end of this section for joining with the second housing part, the mating end of the latter is made with an oblique cut, while an additional insulator in the form of a sleeve with oblique cuts is placed on the cylindrical section of the first part and a retainer sleeve, the latter on the side of the additional insulator made with an oblique cut back, the other end of the retainer sleeve is rigidly connected, for example, with a weld, to the body of the first part, an insulator formed inside the first metal, and on its entire surface is formed of a dielectric layer of high hard.

The required technical result in the aggregate of essential features of the object is ensured by the presence of the above distinctive features in it, and the non-detection in the public sources of patent and technical information of equivalent technical solutions with the same properties implies the compliance of the claimed object with the criteria of novelty and inventive step with obvious industrial applicability.

Figure 1, 2 shows the design of the inventive electric separator for downhole telesystems (with a cut along the axis O-O).

The electrical separator for downhole telesystems (see drawings) consists of a composite of at least two parts 1 and 2 with a channel 3 (for fluid passage) and connecting threads 4 and 5 at the ends of the housing, respectively. An insulating coating 6 is made on the housing, and an electrical insulating coating 7 is placed in the channel 3, while an insulator 8 is placed in the mating parts of the housing parts 1 and 2. The housing parts are connected to each other by tapered threads in the interface 9 containing the aforementioned electrical insulator 8. Part 1 is made with a cylindrical section of a smaller diameter and has a step 10, and the cylindrical section ends with a threaded end 11. The mating end 12 of part 2 is made with an oblique cut along the plane “A” , that is, the latter is not perpendicular to the O-O axis. In the cylindrical section (the section is shown, but is not indicated by a separate position in the drawing) of the part 1, limited by the step 10 and the threaded end 11, there is an additional insulator 13 in the form of a sleeve with oblique sections of the ends, one of which is in contact with the oblique section of the coupling end 12 of the part 2 along the “A” plane, and the other contacts along the “B” plane with the fixing sleeve 14. The fixing sleeve 14, put on the cylindrical section of the part 1, is rigidly connected to the latter by, for example, a circular weld 15 from the ledge 10. After screwing both parts of the housing and the standard tightening of the interface 9, all oblique sections along the planes “A” and “B” are combined to close mutual contact and, for example, weld 15, which ensures reliable protection of the housing parts from any mutual displacement.

The electrical separator for downhole telesystems works as follows: when a signal modulated by an alternating voltage is supplied from the downhole telesystem equipment to electrically isolated parts of the housing 1 and 2, current spreads over the space surrounding the well. The signal reaches the Earth's surface, where it is captured by a ground-based receiver, decoded and used for further processing, while ensuring reliable fixation of any displacement of part 1 relative to part 2 of the body regardless of the intensity and frequency of rotation of the drill string.

The electrical separators made in this way, which have undergone preliminary tests, have shown that the required technical result is fully ensured, the claimed object meets the criteria of the invention and, therefore, is subject to protection by the relevant RF protection document for industrial property.

Sources of information

1. USSR, A.S. No. 941552, M.Kl. ³ E 21 B 44/00, 1980.

2. Assembly drawing, code 6.119.083 SB, Oktyabrsky, VNIIGIS, 1983.

3. RF, certificate for PM No. 17196, M.Kl. ⁷ E 21 V 47/00, prior. 10.23.2000, prototype.

Claims (1)

An electrical separator for downhole telesystems, comprising a composite metal housing with at least two parts with a channel and connecting threads at the ends, an electrical insulating coating of a part of the outer cylindrical surface along the length of the housing, a similar coating of its channel, an electrical insulator in the threaded conical joint of the housing parts, one of the details of the latter are made stepwise, with a ledge and a cylindrical section with a diameter smaller than the case, at the end of this section a nipple is made thread for joining with the second part of the housing, characterized in that the mating end of the latter is oblique cut, while on the cylindrical section of the first part there is an additional insulator in the form of a sleeve with oblique sections of the ends and a retainer sleeve, the latter on the side of the additional insulator with a slant in response to it, the other end of the retainer sleeve is rigidly connected, for example, with a weld seam to the body of the first part, the additional insulator inside is made of metal, and on its entire surface with normed high hard dielectric layer.

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