Downhole petroleum formation fracturing string tension detecting instrument

Abstract

The invention discloses a downhole petroleum formation fracturing string tension detecting instrument which comprises a tension gauge spindle. A pressure-tolerant outer pipe is sleeved on the outer wall of the tension gauge spindle. A sensor, a circuit board, a lithium battery component and a power switch device which are connected are sequentially disposed from top to bottom between the tension gauge spindle and the pressure-tolerant outer pipe. A lower connector is sleeved at the lower end of the tension gauge spindle. The detecting instrument is used for detecting downhole petroleum formation fracturing string tension. The sensor converts strain generated under axial tension of the spindle into impedance variation of strain gauges. The pressure-tolerant outer pipe separates and seals high-pressure downhole liquids to provide a reliable working environments for a tension gauge. A measuring and recording circuit on the circuit board converts the impedance variation into tension and stores data in real time. A lithium battery powers the tension gauge. The power switch is used for cutting off the battery during off-working state to save power. The detecting instrument is unique in design, simple in overall structure, and convenient to maintain.

Description

technical field [0001] The invention relates to an instrument for detecting the tension of a downhole pipe string, in particular to an instrument for detecting the tension of a pipe string tool string for fracturing an oil well formation. Background technique [0002] With the development of offshore and land horizontal oil well drilling and production, the horizontal well downhole layered fracturing technology is becoming more and more mature. However, during the fracturing process, the contact between the flexible pipe string and the downhole wall is complicated, and the theoretically calculated safe fracturing pressure The value is not accurate, and sometimes it even causes accidents of pipe string breakage, resulting in great economic losses. The detection of the actual tension of the fracturing string and the determination of the safe fracturing pressure are the key to the fracturing process. Contents of the invention [0003] The present invention, as an instrument ...

AI Technical Summary

Problems solved by technology

[0002] With the development of offshore and land horizontal oil well drilling and production, the horizontal well downhole layered fracturing technology is becoming more and more mature. However, during the fracturing process, the contact between the flexible pipe string and the downhole wall is complicated, and the theoretically calculated safe fracturing pressure The value is not accurate, and sometimes it even causes accidents of pipe string breakage, resulting in great economic losses

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