A Wellbore Annular Pressure Sensor Based on Microcapacitance

Abstract

The invention discloses a shaft annular pressure sensor based on micro-capacitance. A sensing chamber, a circuit chamber, a cable waterproofing joint and an armored cable are included; the interior ofthe sensing chamber is provided with a first electrode board, a second electrode board, a supporting plate used for supporting the circuit chamber, capacitance is formed by the first and second electrode boards, and the internal distance from the first electrode board to the second electrode board of the sensing chamber is changed due to the deformation of the sensing chamber caused by shaft annular pressure sensor; the interior of the cable chamber is provided with a fixing seat, a supporting seat fixed to the fixing seat, a circuit board fixed to the supporting seat, the circuit board is connected with the armored cable, the first electrode board and the second electrode board, the capacitance of the first and second electrode boards are measured through the circuit board, a shaft annular pressure value is computed based on the capacitance value, and the shaft annular pressure value is transmitted in real time through the armored cable. According to the shaft annular pressure sensor, the pressure is measured by adopting a micro-capacitance principle, the accuracy is high, the size is small, and the sensor is suitable to the environmental demands of shaft working conditions.

Description

technical field [0001] The invention relates to the technical field of geological drilling and instrumentation, in particular to a microcapacitance-based wellbore annular pressure sensor. Background technique [0002] In recent years, with the acceleration of urbanization in China, the demand for energy has increased, and energy issues have become an important factor restricting my country's economic and social development. Therefore, energy exploration and development must be accelerated. In the stage of energy exploration and subsequent development, it is necessary to use drilling technology to evaluate and exploit energy, so drilling is a prerequisite for energy development. [0003] Drilling is the process of using drilling rig equipment and rock-breaking tools to break the formation, thereby forming a hole from the surface to the earth at different depths. The traditional drilling process is generally composed of drilling rigs, drill pipes and drill bits. Among them, ...

AI Technical Summary

Problems solved by technology

At the present stage, most of the existing pressure sensors measure based on the principle of strain, and the radial volume of the sensor is relatively large, which is in contradiction with the narrow space in the radial dimension of the borehole annulus (the radial dimension of the borehole annulus is sometimes only 2 mm in width). , making existing pressure sensors unusable downhole

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