RU2772616C1 - Well temperature measurement device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil and gas industry, in particular to devices for measuring temperature in a well. A device for measuring temperature in a well contains a housing, a power source, a temperature transducer rigidly fixed in the housing and made in the form of a mechanical resonator-tuning fork, wherein one branch of the tuning fork is made of Invar, a material with an independent temperature coefficient of linear expansion, and the other branch is made of bronze, material with an increased temperature coefficient of linear expansion. The device is additionally equipped with a generator, a system for driving and picking up vibrations, a frequency-code converter and a microprocessor, while the output of the generator is connected to the input of the drive system, the output of the pickup system is connected to the input of the frequency-code converter, and its output is connected to the input of the microprocessor, the output of the microprocessor is connected to generator input and communication channel, and the generator, frequency-code converter and microprocessor are connected to a power source - a battery.

EFFECT: increased reliability and accuracy of measuring the temperature of the drilling fluid at the bottom of the well directly in the process of drilling and signal transmission via a wireless electric channel for communication between the bottom and the wellhead by improving the design.

1 cl, 1 dwg

Description

The invention relates to the oil and gas industry, in particular to devices for measuring temperature in a well.

A device for measuring temperature in a well is known (see patent RU No. 2538014, 2015), containing a mechanical oscillatory system with permanent magnets mounted on it and a converter of mechanical vibrations into electrical ones, characterized in that the mechanical oscillatory system is made in the form of a cylindrical bimetallic spiral , one end of which is rigidly fixed, and the other is free, and the converter of mechanical vibrations into electrical ones is made in the form of a system of interacting electromagnetic fields of permanent magnets rigidly fixed on a cylindrical bimetallic spiral, and coils for driving and picking up vibrations, providing transverse vibrations of a cylindrical bimetallic spiral.

The disadvantage of this device is the low reliability and accuracy associated with a small frequency deviation.

A prototype similar in technical essence is a device (see patent RU No. 2713842, 2020), containing a housing, a power source, a temperature converter in the form of two metal rods with a high temperature coefficient of linear expansion, installed coaxially with a gap with the housing and between themselves, rigidly fixed by the ends in a housing having a negative temperature coefficient of linear expansion, while the free end of one rod is equipped with a permanent magnet, the magnetic field of which acts on the field Hall sensor, fixed at the free end of the second rod, the Hall electrodes of the field Hall sensor are connected to the input of the analog-to-digital converter, and its output is connected to the input of the code-to-frequency converter, the output of the latter is connected to the communication channel through frequency division, and the Hall field sensor, analog-to-digital converter, code-to-frequency converter and frequency sensor are connected to a power source in the form of a battery.

The disadvantage of the prototype is the low reliability and accuracy due to the large number of elements and multiple conversions of the measured parameter into the pulse frequency for signal transmission over the communication channel.

EFFECT: improved reliability and accuracy of drilling fluid temperature measurement at the bottomhole directly in the process of drilling and signal transmission via a wireless electrical communication channel of the bottomhole with the wellhead by improving the design.

It is achieved by the fact that a well-known device containing a housing, a power source, a temperature transducer rigidly fixed in the housing, made in the form of a mechanical resonator-tuning fork, and one branch of the tuning fork is made of Invar, a material with an independent temperature coefficient of linear expansion, and the other branch of bronze, a material with a high temperature coefficient of linear expansion, is additionally equipped with a generator, a drive system and vibration pickup, a frequency-code converter and a microprocessor, while the generator output is connected to the drive system input, the pickup system output is connected to the frequency-code converter input, and its the output is with the input of the microprocessor, the output of the microprocessor is connected to the input of the generator and the communication channel, and the generator, the frequency-code converter and the microprocessor are connected to the power source - the battery.

The drawing (Fig. 1 - sectional view) shows the proposed device.

The device comprises a housing 1, a temperature transducer made in the form of a mechanical resonator - a tuning fork 2, a tuning fork vibration drive system 3, with one branch of the tuning fork made of Invar and the other branch of bronze, a generator 4, a vibration pickup system 5, a frequency-code converter 6 , microprocessor 7, while the output of the generator is connected to the input of the drive system, the output of the pickup system is connected to the input of the frequency-code converter, and its output is connected to the input of the microprocessor, the output of the microprocessor is connected to a communication channel (not shown), and the generator, the frequency converter - the code and the microprocessor are connected to the power source 8 - the battery.

The device works as follows.

When measuring the temperature of the drilling fluid flowing in the drill string with a measurement device installed in it in the body 1, one branch of the tuning fork 2, fixed in the body 1, made of a material with a high temperature coefficient of linear expansion (bronze) changes its linear dimensions upwards, and its second branch made of a material with an independent temperature coefficient of linear expansion (invar) changes its linear dimensions in the direction of reduction. As a result, the oscillation frequency of the first branch of the tuning fork 2 decreases, and the oscillation frequency of the second branch with an independent temperature coefficient of linear expansion increases, which leads to a decrease in the quality factor of the tuning fork in proportion to the change in the temperature of the drilling fluid flowing in the drill string. In the drive system 3, connected to the generator 4, an electromotive force (EMF) is induced, which sets the tuning fork 2 in motion, in the vibration pickup system 5, due to vibrations of the tuning fork 2, the corresponding EMF is induced, which is fed to the input of the frequency-code converter 6. The code combination from the output of the converter 6 enters the input of the microprocessor 7, where it is stored in the RAM. The microprocessor 7, using the built-in program, gives a command to change the frequency of the generator 4. As a result of a number of iterations, the frequency response of the mechanical resonator-tuning fork 2 is built in the microprocessor 7, the quality factor of the tuning fork 2 is calculated, which is proportional to the measured temperature of the drilling fluid at the bottomhole according to the formula:

- собственная частота камертона;where

- natural frequency of the tuning fork;

- полоса пропускания;

- bandwidth;

α - coefficient 1÷1.3.

The code combination of the quality factor of the tuning fork 2, which is proportional to the measured value of the temperature of the drilling fluid at the bottom of the well from the microprocessor, is fed into the communication channel of the bottom with the wellhead.

Positive effect - the device has increased reliability and accuracy by reducing the number of temperature-to-pulse frequency conversions using a temperature converter - a tuning fork, using an interference-free frequency method of transmission over a communication channel, greater frequency deviation, increased sensitivity and linearity of the static characteristic.

Claims (1)

A device for measuring temperature in a well, comprising a housing, a power source, a temperature transducer rigidly fixed in the housing, characterized in that the temperature transducer is made in the form of a mechanical resonator-tuning fork, and one branch of the tuning fork is made of Invar, a material with an independent temperature coefficient of linear expansion , and the other branch is made of bronze, a material with a high temperature coefficient of linear expansion, additionally equipped with a generator, a drive and pickup system, a frequency-code converter and a microprocessor, while the generator output is connected to the drive system input, the pickup system output is connected to the converter input frequency-code, and its output - with the input of the microprocessor, the output of the microprocessor is connected to the input of the generator and the communication channel, and the generator, the frequency-code converter and the microprocessor are connected to the power source - the battery.

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