Wellbore annular pressure sensor based on variable displacement mechanism

Abstract

The invention discloses a wellbore annular pressure sensor based on a variable displacement mechanism, which comprises a deformation chamber, a circuit chamber, a cable waterproof joint and an armoredcable, wherein the circuit chamber is internally provided with a circuit board, a fixing plate, a first electrode plate and a second electrode plate, the first electrode plate and the second electrode plate are respectively arranged on two side surfaces of a fixing base, the first electrode plate and the second electrode plate form a capacitor, and the capacitance of the capacitor is measured through the circuit board; the deformation chamber is internally provided with a guide plate, a displacement rod which passes through the guide plate and is used for reflecting the deformation displacement of the deformation chamber, a first connecting rod and a second connecting rod, the first connecting rod and the second connecting rod are connected with the displacement rod, the wellbore annularpressure causes the deformation of the deformation chamber and thus drives the first connecting rod, the second connecting rod and the displacement rod in the deformation chamber to move, and the movement of the displacement rod between the first electrode plate and the second electrode plate will change the capacitance, the circuit board is connected with the armored cable and transmits the capacitance in real time through the armored cable. The sensor disclosed by the invention adopts the variable displacement mechanism to measure the pressure, and is high in accuracy, small in size and suitable for environmental requirements of drilling conditions.

Description

technical field [0001] The invention relates to the technical field of geological drilling and instrumentation, in particular to a wellbore annular pressure sensor based on a variable displacement mechanism. 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...

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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