RU2305182C2 - Logging telemeter system used during well drilling - Google Patents

Abstract

FIELD: well drilling and survey, particularly to transmit well drilling information.

SUBSTANCE: system comprises body with electric column separator, as well as turbogenerator and electronic unit arranged in the separator. Turbegenerator is connected to upper sub of electric column separator. Electronic unit is fastened to lower sub thereof. Air-tight cavities are created in subs adjoining turbegenerator and electronic unit outputs. The air-tight cavities are provided with sealed leads extending from outer body side to the cavities. Connection wires, which connect turbegenerator, electronic unit and electric column separator subs, pass via air-tight cavities through sealed leads, subs and insulation layer of electric column separator. Drilling mud orifices are made in sub bodies. Throttle may be serially connected to turbogenerator winding, wherein electric column separator body is used as throttle core.

EFFECT: increased reliability and decreased diameter of telemetering system.

1 dwg

Description

The proposed solution relates to logging systems during drilling with a cableless electromagnetic communication channel. Preferred application: directional well drilling.

Downhole telemetry systems with an electromagnetic communication channel are known in which communication between the individual blocks of the downhole tool is carried out by cable (Pat. 2140539 RF, IPC ЕВВ 47/12; ПМ 15585 RF, IPC Е21В 47/02). Reliability is reduced due to the long communication lines between the blocks, communication lines occupy the internal space of the telesystems, preventing the reduction of the diameter of downhole tools. Another disadvantage of known telesystems is that with a significant increase in the flow rate of the well fluid and a corresponding increase in the current generated by the turbogenerator, there is the possibility of overheating and failure.

Known telemetry system for logging during drilling (pat. 2190097 RF, IPC ЕВВ 47/12 - prototype). The system includes a housing with an electric column separator, a turbogenerator and an electronic unit. The electronic unit is connected directly to the turbogenerator. Communication with the lower sub of the downhole transmitter is carried out through a connector on the upper sub with access to a conductive non-magnetic grid covering the insulator of the electrical separator of the column. A special device for protecting the turbogenerator from overheating is not provided due to the sufficiently large dimensions of the turbogenerator. But with a decrease in the diameter of the downhole tool, the direct connection of the turbogenerator and the electronic unit was impossible. In addition, due to the decrease in the dimensions of the turbogenerator and the flow rate of the flushing fluid, the thermal regime changes, which leads to overheating of the stator winding of the turbogenerator.

The purpose of the proposed solution is to create a reliable telemetry system of small diameter with an electromagnetic communication channel.

The telemetry system for logging during drilling comprises a housing with an electric column separator (ERC), a turbogenerator and an electronic unit located in it. It is proposed to fix the turbogenerator on the upper sub of the ERC, the electronic unit on the lower sub. In the sub, adjacent to the exits of the turbogenerator and the electronic unit, sealed cavities are made, with hermetic leads leading to them from the outside of the casing. The wires connecting the turbogenerator, the electronic unit and the sub are laid along the sealed cavities, through the pressure glands, the sub and the insulator layer. The body of the sub has holes for the passage of drilling fluid.

Additionally, it is proposed to connect a throttle in series with the winding of the turbogenerator, the core of which is the ERC housing.

The essence of the solution is illustrated in the drawing, which shows two halves of the television system: upper left, lower right. Digital designations: 1 - casing, 2 - turbogenerator, 3 - upper sub of the ERC, 4 - sealed internal cavity of the upper sub, 5 - openings for the passage of well fluid, 6 - pressure glands, 7 - connectors, 8 - insulator ERK, 9 - wire, 10 - lower sub of the ERC, 11 - sealed internal cavity of the lower sub, 12 - electronic unit, 13 - wire forming the inductor coil.

An ERC is built into the housing 1, made of the upper 3 and the lower 10 sub, between which there is an insulator layer 8. In the housing 1, the turbogenerator 2 is rigidly fixed to the upper sub 3, the electronic unit 12 is also rigidly fixed to the lower sub 10. In the sub 3 and 10 sealed cavities 4 and 11 are made, in contact with the outputs of the turbogenerator 2 and the electronic module 12, respectively. For the passage of the borehole fluid in the sub 3 and 10, holes 5 are provided. Electrical wires 9, through which the connection between the the telesystem blocks, are routed through connectors 7 to the corresponding sealed cavities 4 and 11, then through the pressure glands 6 they are led into the bodies of the sub 3 and 10, then to the insulator layer 8. The cable glands 6 and connectors 7 provide sealing of the cavities 4 and 11, necessary for protecting the wires 9 from the influence of the external environment. In the same way, with the help of a separate hermetic input installed in the housing 1 of the television system with access to the electric wires 9, it is possible to install the necessary measuring sensors on the housing of the television system, for example, an electric logging sensor. One of the wires 9, coming from the winding of the turbogenerator 2, forms the winding 13 of the throttle.

A telemetry system for logging while drilling mounted on drill pipes is lowered into the well. The connection between the turbogenerator 2, the electronic unit 12, the measuring sensors and the electrodes of the downhole transmitter is provided by wires 9. In this case, the supply voltage from the turbogenerator 2 to the electronic unit 12 is supplied, the signals from the measuring sensors to the electronic unit 12 and from it to the sub 3 and 10. Transfer communication lines from the internal cavity of the television system into the thickness of the housing, allows you to free up the internal space of the television system and thus reduce its diameter, as well as increase the reliability of the communication lines themselves.

The turbogenerator 2 generally consists of a movable rotor driven by a turbine rotated by a wash fluid stream and a stator winding. With an increase in the rotor speed, the current frequency and voltage in the stator winding increase.

The protection of the turbogenerator against overvoltage outside the internal space of the television system involves one of the wires 9 coming from the turbogenerator 2, wound on the housing 1 and insulated from it. In this case, the housing 1 acts as the core of the inductor. The drawing shows the simplest way to perform: wire 9 is wound on the housing in the insulator layer 8. The core role is played by the base of the insulator 8. The number of turns of the inductor is selected experimentally.

Claims (2)

1. A telemetry system for logging during drilling, comprising a housing with an electric column separator (ERC), a turbo-generator and an electronic unit located in it, characterized in that the turbo-generator is mounted on the upper ERC sub, the electronic unit is on the lower sub, in the adjacent sub to the outputs of the turbogenerator and the electronic unit, sealed cavities are made with hermetic leads leading to them from the outside of the housing, the wires connecting the turbogenerator, the electronic unit, and the ERC sub are laid hermetic cavities through the pressure glands, sub and the insulator layer of the ERK, holes for the passage of drilling fluid are made in the body of the sub. 2. The system according to claim 1, characterized in that a throttle is connected in series with the winding of the turbogenerator, the core of which is the ERC housing.