RU2499138C1 - Method of control over downhole instrument operation - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: proposed method comprises determination of drilling column operating parameters and variation of downhole instrument operation mode depending upon said parameters. Note here that for data transfer to downhole instrument drilling column parameters are abruptly changes by preselected program to fix time intervals between sharp changes in drilling column working parameters with that fixed set of time intervals can be used for variation of downhole instrument operating mode.

EFFECT: simplified and reliable control.

Description

The proposed solution relates to the field of geophysical research of wells. The preferred area is the drilling of directional wells.

When exploring wells with instruments without using a wireline, there is a problem of controlling the operation of the device located in the well. Known downhole recorders included in the program by a timer (Pat. 2296218 RF, IPC E21B 44/00; Pat. 2143557 RF, IPC E21B 47/12). Such solutions are simple to implement, but provide a limited number of operations and are not reliable in operation. The two-way communication channel of the bottomhole mouth (US Pat. RF 2161701, IPC E21B 47/022; US Pat. 4839644, IPC G01V 1 | 00; US Pat. 5412568, IPC G01V 1 | 00) allows you to solve a sufficient number of tasks for controlling the operation of a downhole tool , but it requires significant complication of the downhole equipment, which is not always technologically possible, and reduces the reliability of the equipment in the well.

A known system for transmitting logging information during drilling, in which, in addition to measuring borehole parameters, an essential element of the system is a drill string displacement sensor that disables the system during drilling and turns it on at the moment of stopping drilling. (US Pat. No. 4,597,067; IPC H04H 9/00 - prototype). The method is quite simple structurally, but provides only one operation: turning on / off the downhole tool.

The purpose of the proposed solution is to create a simple and reliable way to control the operation of a downhole tool.

A method of controlling the operation of a downhole tool includes determining the parameters of the mechanical movement of the drill string and changing the operating mode of the downhole tool depending on changes in the parameters of the mechanical movement of the drill string. When transmitting information to the downhole tool, sharp changes in the parameters of the mechanical movement of the drill string are made according to a pre-developed program, the time intervals between sharp changes in the parameters of the mechanical movement of the drill string are recorded in the downhole tool and the operating mode of the downhole tool is changed over a set of fixed time intervals.

The method is as follows. In the downhole tool, a sensor of the parameters of the mechanical movement of the drill string is placed, for example, an accelerometer with a bandpass filter at the output, connected through a decoder to the input device of the downhole tool. In this case, use the property of the accelerometer when a vibration of the drill string occurs to produce a series of high-frequency oscillations at the output. Vibrations of the drill string are formed when there is a sharp change in the parameters of mechanical movement, for example, during sudden braking or jerking. If it is necessary to change the operating mode of the downhole tool, the information is encoded on the surface for transmission to the bottom by an interval code, stop drilling and make a series of changes in the parameters of the mechanical movement of the drill string, for example, allow the string to fall under its own weight and brake sharply, which leads to the appearance of vibrations recorded accelerometer. The number of jerks of the drill string and the length of time intervals between them determine the interval code transmitted to the face, while designating, for example, “0” as a pause of 5 seconds, “1” - 15 seconds. An accelerometer in a well using a band-pass filter selects the braking times of the drill string, transmits data about them to the decoder, which recognizes the incoming code, relying on the gap lengths for “0” and “1” known to the decoder, and transfers it to the input of the downhole tool control device.

You can use a gyroscope as a motion sensor, with the help of which moments of sudden stops of rotational motion are distinguished. Other sensors of the parameters of the mechanical movement of the column are known.

Small changes in the design of the downhole tool and software allow you to turn on / off the downhole tool, change the mode of measurement and / or transmission of information as necessary.

Claims (1)

A method of controlling the operation of a downhole tool, including determining the parameters of the mechanical movement of the drill string and changing the operating mode of the downhole tool depending on changes in the parameters of the mechanical movement of the drill string, characterized in that for transmitting information to the downhole tool, sudden changes are made to the parameters of the mechanical movement of the drill string in advance the program, fix in the downhole tool the time intervals between sudden changes in the parameters of the mechanical movement tions of the drill string and a set of fixed periods of time make changing the mode of the downhole tool.