SU636382A1 - Well level gauge - Google Patents

Description

The invention relates to the oil and gas industry, in particular, to devices for determining the magnitude of increments of ursc fluid in boreholes.

A well-known downhole gauge is known, comprising a separating membrane housing, a piston with a rod, and a balancing spring to the contact converter ij.

A disadvantage of the known device is the presence of a piston rest friction against the walls of a cylinder. The sensitivity threshold of the instrument is 0.7 5% of the measurement limit. Such sensitivity of the device is insufficient in the case of measuring the increments of liquid ursvn in turf wells.

The purpose of the invention is to increase the sensitivity of the level gauge by overcoming the friction of the piston against the walls of the housing.

The goal is achieved by the fact that the level gauge is provided with an electrovibrator concentrically placed in the housing, which is made in the form of an inductance coil and located in its cavity of the plunger of a ferromagnetic material, which is mounted on a piston.

The drawing shows the well

level gauge.

The gauge has a housing 1, inside of which there is an alternating electrical resistance 1 2, a cylinder 3, a piston 4, a cylindrical spring 5 equalizing and a flexible shell tank 6 filled with antifriction separating liquid 7, for example, transformer oil. Lower part

The housing has openings for contact of the tank with the external environment.

Claims (2)

Inside the casing, an inductance coil 8 is fixed, connected via wires 9 and 1 O to a variable frequency sound source (“10 KHz solo; even hell, not shown). The movable contacts 11 of the petal-type electric resistance are placed 36 on the pistons se 12 of the piston 4 connected to the plunger 13 ne of a ferromagnetic material located axially on the axis of the device asymmetrically relative to the center of the inductance. In order to reduce eddy current losses, the plunger 13 is assembled from individual permalloy plates of annular shape. The moving contacts of the electrical resistance are closed on the instrument case, and the fixed contact of this resistance is connected to the output of the sensor from the sensor 14 cm allows measuring the value of this resistance at a distance. When measuring, the level gauge is lowered into the borehole on the cable, which is obviously lower than the expected fluctuations in the level of the liquid. The separation fluid 7 in the flexible sheath reservoir 6 protects the piston 4 and the cylinder 3 from chemical exposure to the external environment, but transfers its pressure to the piston. The external pressure on the pistons and the attractive force of the ferromagnetic plunger 13 by the coil 8 are equalized by the compression of the spring 5. The external pressure changes, i.e. the height of the liquid column above the ursanemer causes a displacement of the piston n and, therefore, a change in the magnitude of the variable resistance 2. As shown by the analysis of theoretical positions, the length of the piston movement is directly proportional to the change in external pressure. The variable resistance is via pin 14 and the body of the level gauge is connected to the electrical circuit on the surface for remote measurement. The same electrical circuit provides power for the inductance coil with an alternating sinusoidal current with a frequency of about 1 KHz. The alternating magnetic field of the coil, along with the constant attraction of the ferromagnetic plunger 13, causes its oscillatory movements along the axis of the coil with the frequency of the supply voltage and small amplitude, which practically does not affect the measurement of the value of the variable resistance. Constant oscillations of the plunger 13 and the associated piston 4 lead to overcoming the force of the resting friction, which, as is known, is greater than the force of the friction movement (sliding). As a result, the sensitivity of the proposed level gauge significantly exceeds the sensitivity of the known level gauge. The gauge can work in automatic mode. The relationship between the magnitude of the variable resistance and the height of the liquid column above the device is established as a result of the calibration, i.e. lowering the instrument below the static level at fixed intervals. Deep ursenamer successfully passed production tests. According to the test results, the sensitivity of the proposed depth gauge is O, 1% of the measurement range, which is 7.5 times higher than the sensitivity of the known. The invention The downhole gauge comprising a housing, a separating membrane, a piston with a rod, a balancing spring and a contact transducer, characterized in that it is fitted with an electrovibrator concentrically located in the housing in order to detect the sensitivity of the gauge It is made in the form of an inductance coil and a plunger located in its cavity of ferromagnetic material, which is mounted on the piston rod. Sources of information taken into account in the examination: “1. Ageikin D.I. Sensors of control and regulator. M., Mechanical Engineering, p. 573-574. /four