Scale device for transient electromagnetic resistivity logging instrument

Abstract

The invention belongs to the technical field of resistivity measurement of petroleum logging construction stratums and particularly relates to a scale device for a transient electromagnetic resistivity logging instrument. The scale device is simple and compact in structure, easily achieves configuration of its resistivity standard values and accordingly completes adjustment of engineering values output after measurement performed by the transient electromagnetic resistivity logging instrument. The scale device for the transient electromagnetic resistivity logging instrument comprises a borehole casing pipe, a water tank container sleeving the periphery of a borehole and receiving coil systems put in the borehole casing pipe, wherein the water tank container is a resistivity adjusting cavity, an isolation baffle is arranged in the resistivity adjusting cavity and divides the inside of the resistivity adjusting cavity into first and second internal cavities which are identical in size and shape, the first receiving coil system is arranged at the first internal cavity, the second receiving coil system is arranged at the second internal cavity, the first receiving coil system and the second receiving coil system are opposite in winding direction, and dotted terminals are connected and then are led out so as to form a comparative receiving coil system.

Description

technical field [0001] The invention belongs to the technical field of formation resistivity measurement in oil well logging construction, and in particular relates to a calibration device for a transient electromagnetic resistivity logging instrument. Background technique [0002] Transient electromagnetic resistivity logging technology, as a new type of logging technology, can be used in logging fields such as open hole and cased hole to realize the extraction of formation resistivity information. [0003] Existing transient electromagnetic resistivity logging tools usually use periodic bipolar rectangular pulse sequences to load the transmitting coil. During the launching process, the transmitting coil is loaded with a short-term direct current, so that the electromagnetic conversion is formed on the transmitting coil, thereby generating a stable primary magnetic field in the medium around the well. After the transmitting coil is powered off, the primary magnetic field i...

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Problems solved by technology

However, the inventors have found that after the existing transient electromagnetic resistivity logging instrument is designed, the scale device is also correspondingly finalized, and it is difficult to change it. Therefore, it becomes very difficult to adjust its scale device. The standard resistivity formation environment is also difficult to change, causing inconvenience in the calibration process of transient electromagnetic resistivity logging tools

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