RU2591997C1 - Above-drill bit module - Google Patents

Abstract

FIELD: measuring equipment.

SUBSTANCE: invention relates to geophysics, particularly, to devices for measuring geophysical and technological parameters during drilling and their transfer to surface. Device comprises housing with central flushing hole, central electrode electrically insulated from housing located between insulators arranged in grooves of housing, in its sealed part, separated by sealing elements, electric board. Isolation of central electrode from housing is made in form of separate rings made of insulating material arranged in grooves on surface of housing from side of its sealed part in close proximity to seats of sealing rings and in places of grooves with electric circuit boards in housing. Mating parts of housing and central electrode are arranged with clearance, increased to height of projection insulating rings over surface of housing. To provide specified nominal size of gap for mating parts at installation of sealing elements electrical insulating rings protrude above surface of housing by value required to achieve specified nominal clearance. Electrical insulating rings on housing can be installed in several rows. Size of individual electric insulating rings at points of recesses with electric circuit boards in housing is selected in accordance with dimensions of places for location of said recesses.

EFFECT: longer life, higher reliability.

1 cl, 5 dwg

Description

The invention relates to the field of field geophysics, and in particular to devices for measuring geophysical and technological parameters during drilling and transferring them to the surface.

A device is known for measuring geophysical and technological parameters during drilling with an electromagnetic communication channel, consisting of a downhole telemetry system including a drill string, a power supply, measuring modules, a transmitter module with a receiving-processing unit, an electrical splitter and an additional separately installed in the drill string a measuring module comprising a housing with a central flushing hole, a central electrode located between the insulators and the electric isolated from the case, as well as electrical boards located in the recesses of the case in its sealed part, measuring sensors, a power source and a transmitter, according to the invention, said central electrode located between the insulators on the case and the sealed part of the case with recesses containing the above elements, separated from each other (the central electrode is removed from the sealed part of the housing), while the specified central electrode is equipped with point electrical contacts isolated from the core baleen. Point electrical contacts are connected to electric circuit boards by wires laid in the channels of the walls of the housing by current conductors with pressure leads at the ends (Pat. RF No. 2351759, prior. 07.09.2007, publ. 10.04.2009).

In the known device, the problem of preserving electronic circuit boards from the effects of an aggressive downhole environment is solved due to the fact that the central electrode located between the insulators on the housing and the sealed part of the housing with recesses containing the above elements are separated from each other (the central electrode is removed from the sealed part of the housing ) Due to this, electronic boards are under reliable protection of the whole case, not weakened by an insulating material, the strength characteristics of which are less than that of the metal from which the whole case is made.

A disadvantage of the known device is due to the need to increase the length of the product to accommodate the remote central electrode. When installing the known device on the shaft of the volumetric engine, the distance from the place of curvature of the volumetric engine to the bit increases, thereby reducing the accuracy when controlling the layout for choosing the direction of drilling the wellbore. In addition, the known device is difficult to manufacture and assemble the structure due to the laying of wires connecting the point electrical contacts to the electrical boards in the channels of the walls of the housing.

A device for the over-bit module is known in which the safety of electronic boards located in the sealed part of the housing is ensured by sealing elements located in the housing under the central electrode between its insulators (Pat. RF No. 2509209, prior. 08.21.2012, publ. 10.03.2014 g.). Selected as a prototype of the claimed over-bit module.

Known over-bit module contains a housing with a central flushing hole, a central electrode electrically isolated from the housing located between the insulators, and also electrical boards located in the recesses of the housing, in its sealed part, separated by sealing elements.

The design of the sealed part of the above-bit module is also disclosed in the description of utility model No. 27839 (prior. 05/30/1002, publ. 02/20/2003).

A device for measuring geophysical and technological parameters during drilling with an electromagnetic communication channel, consists of a downhole telemetry system, including a drill string, a housing, a power supply, measuring modules, a transmitter module, an electrical divider, made in the form of a separate sub, installed directly above the bottomhole an engine in which an over-bit module (NDM) is mounted directly above the bit, connected to the shaft of the downhole motor, while the NDM consists of From the casing with a central flushing hole, on which the central electrode is located, located between the insulators and electrically isolated from the casing, there are electric boards, measuring sensors, a power source and a transmitting device in the casing, and a receiving-processing device is introduced into the transmitter module of the downhole telemetry system receiving electromagnetic signals from NDM.

At the same time, recesses are made in the housing of the over-bit module, in which there are electrical boards, measuring sensors, a power source and a movable contact assembly connecting the electrical board to the central electrode.

The central electrode of the bitwise module is isolated from the casing with a special coating of electrical insulation material and placed between the insulators, and the electric boards, measuring sensors and a power source are located in the sealed part of the bitwise module, isolated from the ingress of well fluid using sealing elements.

During operation of the above-bit module, a layer of insulating material, which is a continuous coating applied to the device’s body, is subjected to the damaging effects of dynamic loads during drilling, cracking, peeling from the case, the electrical insulation of the central electrode is broken, the device malfunctions . According to statistics, the insulation layer withstands one or two descent of the device into the well, after which the entire device is lifted to the surface and the insulation layer is repaired. This drawback reduces the reliability of the device and reduces the life of the BAT.

The objective of the proposed above-bit module is to increase the service life and increase the reliability of the design.

This problem is solved by the fact that in the over-bit module containing the casing with the central flushing hole, the central electrode is electrically isolated from the casing, located between the insulators, and also located in the recesses of the casing, in its sealed part, separated by sealing elements, electrical boards, unlike known, the isolation of the central electrode from the housing is made in the form of separate rings of electrical insulation material located in the grooves on the surface of the housing from its seal side part, in close proximity to the seats of the sealing rings, and in the places of recesses with electric boards in the housing, while the mating parts of the housing and the central electrode are installed with an increased clearance, and to ensure a regulated nominal size of the gap for the mating parts when installing the sealing elements, electrical insulating rings protrude above the surface of the housing by the amount necessary to achieve the specified nominal clearance. The insulating rings on the body can be installed in several rows. The size of the individual electrical insulating rings in the places of the recesses with electric boards in the housing is chosen in accordance with the size of the places for the location of these recesses.

In FIG. 1 shows the design of a super-bit module with an insulating layer.

Figure 2 is a callout A showing the placement of the insulating layer on the housing.

In FIG. 3 shows the design of the proposed over-bit module.

In FIG. 4 is a callout G showing the placement of electrical insulating rings on the housing of the proposed over-bit module.

In FIG. Figure 5 shows the design of the over-bit module with electrical insulating rings mounted on the housing in several rows.

According to the description of patent No. 2509209, the central electrode 1 of the over-bit module is isolated from the housing 2 by a special continuous coating of electrical insulating material 3 and placed between the insulators 4, and the electric boards, measuring sensors and a power source (not shown in Fig.) Are located in the sealed part of the bit-and-block module, isolated from the ingress of well fluid using sealing elements 5 (Fig. 1).

In FIG. 2 it can be seen that a special layer of electrical insulating material 3 covers the housing 2, and the seats 7 under the sealing elements 5, so that the central electrode 1 is insulated from the housing 2.

In this case, the nominal clearance B during assembly of the mating parts, which are the central electrode 1, in which the housing 2 is placed with the gap, is maintained according to the generally accepted GOST, which regulates the nominal size of the gap for the mating parts.

The proposed NDM (Fig. 3, 4, 5) contains a central electrode 1 located on the housing 2 between the insulators 4. Electric boards, measuring sensors and a power source (not shown in Fig.) Are located in the sealed part of the over-bit module isolated from the well fluid using sealing elements 5, and are placed in the recesses 6 of the housing 2.

In the proposed above-bit module (Fig. 3, 4, 5), the isolation of the central electrode 1 from the housing 2 is made in the form of separate electrical insulating rings 8 installed in the grooves 9 on the housing 2, in the immediate vicinity of the seats 7 of the sealing elements 5 and individual electrical insulating rings 10 located on the housing 2 of the NDM in places with recesses 6, where the electrical circuit boards are located.

In this case, the assembly of the mating parts: the central electrode 1 and the housing 2, is carried out with an increased gap B by the size of the protrusion 11 of the insulating rings above the surface L of the housing 2. The height h of this protrusion allows for a regulated nominal size of the gap B for the mating parts of the housing 2 and the central electrode 1 in places of installation of sealing elements 5 of the selected size in accordance with generally accepted GOST. The size of the individual electrical insulating rings 10 on the housing 2 of the NDM in places with recesses 6, where the electrical boards are located, is selected according to the size of the places for the location of the recesses 6.

Compliance with the regulated sizes ensures reliable sealing with the help of sealing elements 5 and isolation of the central electrode from the housing with the help of electrical insulating rings 8, the protrusion 11 of which also serves as an additional stop for the sealing elements 5. The electric boards in the recesses 6 of the housing 2 are protected by electrical insulating rings 10, which at the increase in borehole pressure does not allow the walls of the central electrode 1 to bend towards the recesses.

With increased borehole pressure, electrical insulating rings are installed in several rows on the casing (Fig. 5).

A feature of the proposed design is the use of separate electrical insulating rings instead of a continuous insulating coating.

As a result, the reliability of the structure is increased and the service life of the device is increased, in which there is no continuous insulating layer, subject to delamination and destruction during rotation of the over-bit module together with the bit.

Claims (2)

1. A hollow module containing a housing with a central flushing hole, a central electrode electrically isolated from the housing located between the insulators, and also located in the recesses of the housing, in its sealed part, separated by sealing elements, electrical boards, characterized in that the central electrode is insulated from the housing is made in the form of individual rings of electrical insulating material located in grooves on the surface of the housing from the side of its sealed part, in close proximity and to the seats of the sealing elements, and in the places of recesses with electric boards in the housing, while the mating parts of the housing and the central electrode are installed with a gap increased by the height of the protrusion of the insulating rings above the surface of the housing, and to ensure a regulated nominal size of the gap for the mating parts in places of installation of sealing elements, insulating rings protrude above the surface of the housing by the amount necessary to achieve the specified nominal clearance, the size of the individual electrical insulating rings in the places of the recesses with electric boards in the housing is selected in accordance with the size of the places for the location of the said recesses. 2. The pre-bit module under item 1, characterized in that in the grooves on the housing surface from the side of its sealed part, in close proximity to the seats of the sealing elements, more than one row of electrical insulating rings is installed.

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