SU446013A1 - Well moisture meter - Google Patents

Abstract

Borehole moisture containing coaxial capacitor sensor, an external non-insulated electrode which is made in the form of several rods, forming a protective casing of the sensor, & the internal electrode is made isolated, and. Also, a measuring circuit, characterized in that, in order to improve measurement accuracy, as well as reliability of the moisture meter in wells with elevated temperature and pressure, an internal non-insulated electrode, made in the form of a rod and placed along the central axis of the sensor, is inserted into the sensor, and the isolated electrode is made from the hermetic wire, placed between the external and internal non-isolated electrodes and fixed in the form of several loops parallel to the terminals of the external non-isolated electrode. (P

Description

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The invention relates to devices for determining the water content of a well in a fluid. It can be used to solve other oilfield problems arising during the development of oil fields.

Borehole moisture meters are known that contain a capacitor sensor, one electrode of which is an insulated rod, and the other, uninsulated, is a protective casing surrounding the insulated rod. The casing is fitted in the form of several rods.

Hydrometers with such a sensor, despite their reliability and efficiency, have significant drawbacks, the main one being the constructive design of an isolated sensor electrode. In all known moisture meters, an insulated electrode is a metal rod electrically insulated from a squat environment with a high-quality, electrically insulating coating made more often. total of epoxy resins. The application of epoxy coating is rather complicated from the point of view of technical implementation and the process is harmful according to the conditions of labor. The resulting sensors have a significant variation of parameters, especially in their own capacity, which requires, in the future, when working with them, individual adjustment and calibration of each device.

In addition to the electrical strength, the insulation coating must have sufficient mechanical strength to ensure the study of wells with a pressure of 300-350 atm and temperatures of SO-IOO C,

The implementation of the insulated electrode in the form of a solid rod causes an additional error in the measurements, due to the capacitance of the sensor between the casing and the areas of the insulated rod, on overlapping non-insulated rods. This capacitance may vary with the movement of the instrument regardless of changes in the composition of the well fluid.

The purpose of the invention is to increase the measurement accuracy and simplify the manufacturing technology of sensors for downhole moisture meters.

The goal is achieved due to the fact that the insulated electrode of the sensor is made of a hermetic wire placed in the form of several parallel branches with small gaps between the external and internal non-insulated electrodes. In addition, an internal non-insulated electrode is inserted into the sensor in the form

rod mounted on the central axis of the sensor.

Such a design of the sensor of the moisture meter greatly simplifies the technology of its manufacture, ensures the reliability of its operation in wells with a pressure of 500-700 atm and temperatures of 150-200 ° C.

Due to the introduction of an internal non-insulated electrode, which forms a gap with an insulated sensor and increases the working capacity of the sensor, the volume of liquid under study increases and, consequently, the sensitivity of measurements, the measurement accuracy is increased due to the performance of sensors that are completely identical in parameters. Since the insulated wire is located beneath the rods of the non-insulated electrode, the capacity of the casing string, which introduces additional error, is minimal.

Fig. 1 shows a proposed downhole moisture meter with a sensor, a longitudinal section; figure 2 is the same, the section aa in figure 1.

The depth gauge of the moisture meter contains a capacitor sensor consisting of an insulated electrode 1, made in the form of insulated sealed wires fixed parallel to the rods m 2 by means of washers 3 having openings for passing wires and grooves for

rods, 5.

The geometrical dimensions of the sensor are ensured by tightening the wires in the axial direction.

end nut 4 fixed 0 "together with washers on metal

a rod with a threaded surface 5, which is an internal insulated electrode. The insulated wire through the sealing cuff 6 is introduced into the transition bridge 7 and through the contact 8 is connected to the measuring circuit located in the container 9.

The moisture meter, like other wells: instruments, is lowered into the well on the cable. In the well test interval, the water-to-oil mix falls into the working gaps of the sensor. According to the volume ratio of water and oil, the electrical capacitance of the sensor changes, which is fixed by the measuring circuit, transmitting signals through the cable to the surface,

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Claims (1)

A Borehole Moisture Meter containing a coaxial capacitor sensor, the external non-insulated electrode of which is made in the form of several rods forming the protective cover of the sensor, and the internal electrode is insulated, as well as a measuring circuit, characterized in that, in order to improve the accuracy of measurements, as well as the reliability of the moisture meter in wells with elevated temperature and pressure, an internal non-insulated electrode is introduced into the sensor, made in the form of a rod and placed along the central axis of the sensor, and the isolation This electrode is made of a sealed wire, placed between the external and internal non-insulated electrodes and fixed in the form of several loops parallel to the rods of the external non-insulated electrode.