RU2309249C2 - Bottomhole telemetering system with wired communication channel - Google Patents

Abstract

FIELD: well logging, particularly to measure bottomhole parameters during well drilling.

SUBSTANCE: system comprises drilling string with electric divider arranged in upper drilling string part, turbogenerator, measuring module, sending module and centralizers, as well as bottomhole motor with drilling bit and wired communication channel having joint unit. The system additionally has diamagnetic pipe installed in lower part of drilling string. Turbogenerator, measuring module, sending module and centralizers are placed in diamagnetic pipe. Wired communication channel has electrode fixed in drilling string and arranged at electric divider output. Wired communicational channel branch between sending module and joint unit passes in space between bodies of above modules and diamagnetic body. Communication wire passes through centralizers. Joint module is installed over diamagnetic pipe.

EFFECT: simplified technology of telemetering system lowering in well, improved operational reliability and simplified structure.

2 dwg

Description

The proposal relates to the field of field geophysics and is intended to measure downhole parameters during drilling.

A downhole telemetry system (telesystem) is known having a modular layout and comprising a power supply unit (turbogenerator), a control and communication module (transmitting device), measuring modules, an electrical splitter connected to the downhole motor. A feature of the system is that the diameters of the housing of the measuring modules and the power unit (turbogenerator) are made smaller than the inner diameter of the drill string. In this case, the power supply unit, the measuring and transmitting modules are interconnected by flexible in the radial direction and rigid in the longitudinal direction connections, and as connections between the modules, metal pipes flexible in the radial direction can be used with a diameter smaller than the diameter of the module casing. Inside the flexible pipes are placed electrical wires that provide electrical communication between the modules. Centralizers are installed at the base of the modules. In addition, the electric splitter is made in the form of a separate sub installed directly above the downhole motor (RF patent No. 2105880, MKI E21B 47/12, bull. No. 6, 1998).

The design drawback is that the electric separator installed in the lower part of the drill string does not provide the necessary signal level when working in deep and superdeep wells.

A downhole telemetry system is known, consisting of a borehole module with measuring primary transducers, a transmitter with an electric dipole formed as a result of separation of the lower part of the drill string from upper and ground receiving and processing equipment, a wired communication channel connecting the transmitter to the borehole module, in which an electric dipole installed in the upper part of the drill string (RF patent No. 2140539, MKI E21B 47/12, bull. No. 30, 1997).

The device solves the problem of increasing the range and speed of transmitting information about downhole parameters in real time during drilling, regardless of the depth of the well.

A disadvantage of the well-known downhole telesystem is as follows. Placing the transmitting device in the upper part of the drill string causes a change in the design of the standard telemetry system, where the transmitting module is installed in the lower part of the drill string, which leads to additional changes in the descent technology and complicating the design.

In addition, when deepening the bit, it is necessary to build up the cable through which the signal from the bottom is transmitted. The lack of quick contact complicates this operation.

This disadvantage is partially eliminated in the invention according to the patent of the Russian Federation No. 2193656, MKI E21B 47/12, publ. November 27, 2002 (the invention was taken as a prototype of the claimed invention).

The composition of the known device includes: a bit, a downhole motor, a downhole tool with measuring primary transducers, a transmitter, an electric generator, a main electrical splitter installed in the lower part of the drill pipe string, an additional electrical splitter installed in the upper part of the drill string, above which the docking unit is fixed having a latch and a switch for connecting to a transit wire. The transit wire passes inside the downhole tool and the generator. In this case, the docking unit is configured to provide tightness inside the cavity of the generator.

The device solves the problem of increasing the range and speed of transmitting information about downhole parameters in real time during drilling, regardless of the depth of the well and the electrical resistance of the rocks.

A disadvantage of the known design is the difficulty in solving the problem of passing the transit wire inside the downhole tool and electric generator. The need to make a docking unit that provides tightness inside the cavity of the generator also complicates the design and reduces operational reliability.

The proposed telesystem with a wired communication channel solves the problem of simplifying the technology of lowering the downhole telesystem into the well, increasing operational reliability and simplifying the design.

In a downhole telemetry system with a wired communication channel containing a drill string with an electric separator installed in its upper part, a turbogenerator, a measuring module, a transmitting module and centralizers, a downhole motor with a chisel and a wired communication channel with a docking station; the system is equipped with a diamagnetic pipe installed in the lower part of the drill string, while the turbogenerator, measuring module, transmitting module and centralizers are installed in the diamagnetic pipe, the wire communication channel at the outlet of the electric separator is equipped with an electrode fixed in the drill string, the branch of the wire communication channel between the transmitting module and the docking unit is passed in the space between the cases of the above modules and the diamagnetic case, while the communication wire is passed through centralizers, and the docking station is mounted above the diamagnetic pipe.

Figure 1 shows a downhole telesystem with a wired communication channel and a quick-disconnect electrical contact (docking station).

Figure 2 shows the docking node in the form of a quick disconnect electrical contact.

The downhole telesystem with a wired communication channel (Fig. 1) contains a drill string 1, to the bottom of which a diamagnetic drill pipe 6 is attached, inside of which are installed: a turbogenerator 2, a transmitting module 3, a measuring module 4 with a branch of a wire connection 5. Branch of a wire connection 5 passed in the space between the enclosures of the indicated modules and the diamagnetic casing 6. A downhole motor 7 is installed at the bottom of the television system. An electric separator 8 is located above the diamagnetic casing 6, at the output of which an electrode 9 is fixed at threaded nuts 10. A quick-disconnect electrical contact 11 is installed above the diamagnetic pipe 6. The specified electrical contact 11 is connected to the electrode 9 by a wire communication branch 12. 13 are centralizers of module housings.

The docking unit (figure 2) in the form of a quick-disconnect electrical contact 11 contains a plug and a socket with corresponding housings 14 and 15, equipped with permanent magnets 16 and 17, mounted coaxially at the junction. The shape of the magnets can be different: circular, segment, etc.

Assembling the downhole telesystem is as follows.

A diamagnetic pipe 6 (non-magnetic standard drill pipe) is screwed onto the downhole motor 7, into which the measuring module 4, the transmitting module 3, and the turbogenerator 2 are lowered, connected by flexible connections to centralizers. The diamagnetic pipe 6 is connected to a standard drill string 1, which descends to the bottom of the well. In this case, the quick disconnect contact 11 is removed from the diamagnetic pipe 6.

The standard drill string 1 descends to the calculated length, then an electric splitter 8 with an electrode 9 is connected to it, connected to a wire communication cable 12.

When connecting the electrical splitter 8, the wire communication branch 12 is connected to the wire communication branch 5 using a quick-disconnect electrical contact 11. Since the quick-connect electrical contact contains a plug and a socket, in the housings of which coaxial magnets 16 and 17 are installed, the contact occurs quickly and does not require additional operations with electric cable.

The telesystem works as follows. After the television system is lowered to the bottom of the well, the mud pump is pumped to the surface (not shown in the figure), and a turbogenerator is turned on, providing power to the system modules and transmitting the signal through a wired communication channel (electric cable).

Information about the parameters from the bottom comes from the measuring module 4 to the transmitting module 3, where it is encoded, amplified by power, and with the help of an electric dipole formed as a result of the separation of the lower part of the drill string from the top by an electric separator 8, is transmitted to the rock. The signal propagated through the breed is captured by the antenna and fed to the receiving-processing complex on the surface (not shown in the figure). Thus, the well-known principle of signal transmission through the electromagnetic communication channel is implemented.

In the inventive device, the signal is transmitted from the bottom of the well to the surface using both a wired communication channel to the electrode and a wireless communication channel, which provides the following advantages: no design changes are required for the television system to output the communication branch 5, the assembly technology of the television system with an extended lower dipole is simplified , the same telesystem can be used in any combination of installing an electrical separator, the connection length between the quick-disconnect electrical contact 11 and the electrode 9 is not limited since it is always possible to install additional specified electrical contacts, no changes are required in the design of the diamagnetic pipe for wiring the communication line.

Claims (1)

A downhole telemetry system with a wired communication channel, comprising a drill string with an electric splitter installed in its upper part, a turbogenerator, a measuring module, a transmitting module and centralizers, a downhole motor with a chisel and a wire communication channel with a docking unit, characterized in that the system is equipped with a diamagnetic pipe installed in the lower part of the drill string, wherein said turbogenerator, measuring module, transmitting module and centralizers are installed in a diamagnetic pipe, wired the communication channel at the outlet of the electric separator is equipped with an electrode fixed in the drill string, the branch of the wire communication channel between the transmitting module and the docking node is passed in the space between the housings of the above modules and the diamagnetic housing, while the communication wire is passed through centralizers, and the docking node is installed above the diamagnetic a pipe.

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