Downhole Quartz Resonant Pressure Sensor

Abstract

A downhole quartz resonant pressure sensor, which includes a cylindrical housing, a quartz crystal resonator and a bracket arranged in the housing, the quartz crystal resonator is embedded in the bracket, and the bracket is fixedly installed in the housing; the housing There is a screw hole in the center of one end of the housing, and a fine-tuning screw is inserted into the screw hole. The other end of the housing is provided with a pressure detection window. The pressure detection window is sealed with an elastic metal diaphragm. Corresponding to the center of one side of the shell, there is a convex column; the quartz crystal resonator is an open ring sheet-shaped 4.992MHz quartz crystal resonator with a fifth-order overtone thickness shear vibration mode, and a quartz crystal resonator is welded on it. For the sealed lead-out ends of the electrodes passing through the shell; the corresponding ends of the fine-tuning screw and the protruding post are respectively inserted into the bracket, and the force-sensitive points of the quartz crystal resonator are in contact with the corresponding end faces of the fine-tuning screw and the protruding post respectively.

Description

technical field [0001] The invention relates to the field of pressure sensors, in particular to a downhole quartz resonant pressure sensor used for oil well pressure measurement in the field of oil exploitation. Background technique [0002] Pressure sensor is the most commonly used sensor in industrial practice. It is widely used in various industrial automatic control environments, involving water conservancy and hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, military industry, petrochemical, oil wells, electric power, ships, machine tools , pipeline and many other industries. There are many types of pressure sensors and their application fields are extremely wide, but there are only a handful of sensors that can be used for downhole pressure measurement in oil fields. Due to the high pressure, high temperature, serious well fluid erosion and harsh working conditions of oil wells, the requirements for pressure sensors a...

AI Technical Summary

Problems solved by technology

[0005] The present invention provides an underground quartz resonant pressure sensor. The main technical problems to be solved are: the traditional quartz resonant pressure sensor has complex structure, difficult processing and high cost, and the electrode part of the vibrator is exposed to the test environment. When the cylinder confining pressure medium contains electrolyte components, the output amplitude of the sensor will be reduced, and in severe cases, it will not work; the sensor is protected with a metal cylinder with a pressure transmission hole, and the capillary is filled with pure silicon oil to isolate the well fluid The way to suppress the decrease of the output amplitude of the sensor will bring a lot of inconvenience to the field use

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