Sampling resistor-based well logging during drilling instrument protecting device

Abstract

The invention discloses a sampling resistor-based well logging during drilling instrument protecting device which comprises a circuit board, wherein a sampling resistor, a voltage comparator, a single-chip microcomputer and an MOS switch module are arranged on the circuit board; the sampling resistor is connected with a power supply interface of an underpit petroleum logging instrument, the voltage comparator is connected with the sampling resistor, and the single-chip microcomputer is connected with the voltage comparator and the MOS switch module. Via an over-current protection device of the well logging during drilling instrument protecting device, a circuit of the petroleum logging instrument can be timely turned off and be protected when a system work current suddenly increases in underpit well drilling processes; when the current is back to normal, the single-chip microcomputer automatically controls a relay device to switch on the circuit, electric power can be supplied to the circuit normally, and manual fuse wire replacement is not needed; manpower and material resource cost can be saved, and petroleum logging efficiency can be greatly improved.

Description

technical field [0001] The invention relates to the field of petroleum exploration and well logging, in particular to a protection device for logging while drilling tools based on sampling resistance. Background technique [0002] LWD (Logging While Drilling) in the petroleum industry generally refers to measuring formation petrophysical parameters during the drilling process, and using the data telemetry system to send the measurement results to the ground in real time for processing. Due to the limitations of current data transmission technology, a large amount of data is stored in the memory of downhole tools and played back after drilling. MWD (Measurement While Drilling) generally refers to the measurement of drilling engineering parameters, such as the measurement of well deviation, azimuth and tool face. Sometimes, MWD refers to all downhole measurements while drilling. [0003] Since the formation parameters obtained by logging while drilling are the formation para...

AI Technical Summary

Problems solved by technology

But this kind of fuse can only protect once, and it needs to be replaced if it is blown. When replacing the fuse, the construction needs to be interrupted, and the whole string of instruments should be lifted up from the wellhead, which is time-consuming and laborious.

At present, the operating temperature range of most resettable fuses on the market is between -40°C and 85°C, which cannot meet actual needs.

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