EM-MWD relay transmission system

Abstract

The invention provides an EM-MWD relay transmission system. The EM-MWD relay transmission system comprises drill rods, a drill tool, an insulation module, an electromagnetic signal transmitting module, an electromagnetic signal receiving module and one or more relay short-circuit modules, wherein the relay short-circuit modules are arranged among the drill rods, and spacing distances of more than one relay short-circuit modules can be set on the premise that signal strength of the electromagnetic signal receiving module during signal receiving is larger than or equal to a threshold value. The EM-MWD relay transmission system prolongs an EM-MWD transmission distance through relays. If the transmission distance is not enough in the EM-MWD process while drilling, relay short circuits can be increased to continue to perform transmission. In addition, the transmission speed can be improved by improving frequency, even though improved frequency likely enables an original EM-MWD transmission distance to be shortened, the whole transmission distance is not limited by adopting the relays.

Description

technical field [0001] The invention belongs to the technical field of transmission while drilling, in particular to the wireless electromagnetic transmission technology of signals while drilling. Background technique [0002] In oil exploration and other geological drilling projects, the electromagnetic measurement-while-drilling (EM-MWD) technology, which uses metal drill pipe as an asymmetrically excited dipole antenna to realize logging-while-drilling signal transmission, is one of the research focuses in recent years. This method overcomes the shortcoming that mud pulse cannot be applied in air drilling, and has no requirement on mud quality. [0003] EM-MWD uses the drill pipe as an antenna. By setting the insulation module near the drill bit of the drill pipe, the upper and lower ends of the insulation module are powered and excited. Therefore, the entire drill pipe and drilling tools form a very asymmetrical dipole antenna. , The transmission of signals is realized ...

AI Technical Summary

Problems solved by technology

Therefore, its transmission distance is usually limited

In addition, since the transmission distance of EM-MWD is related to the formation parameters, and the formation parameters are usually unknown, it is difficult to determine how far the transmission distance of the drill pipe antenna based on asymmetric excitation is, so there will be such a problem in the application process Problem, when the transmission distance is found to be insufficient during the drilling process, there is no remedy

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