Calibration method based on electric field theory for near-drill wireless short transmission ground environment

Abstract

The invention mainly belongs to the field of measurement-while-drilling, and specifically relates to a calibration method based on the electric field theory in a near-drill wireless short-transmission ground environment. The circuit of the electric field signal is formed by copper wire connection, the emitter is connected to the transmitting circuit to realize signal transmission, the receiver is connected to the receiving circuit to realize signal reception, and the amplitude relationship between the transmitted signal and the received signal is realized by measuring the amplitude relationship between the transmitted signal and the received signal under different resistivities of the solution. Calibration of optimal power and receive gain. The invention can completely replace the calibration in the well site environment, and the research and development and testing of the near-drill wireless short transmission system based on the electric field theory can be realized in the laboratory. The environment is simple to build, the simulated wireless channel is stable, and the resistivity environment is convenient to modify. Traverse the wellbore environment of all resistivity environments, speed up the research and development cycle of the wireless short transmission system, and reduce the research and development cost.

Description

Technical field [0001] The invention mainly belongs to the field of measurement while drilling, and specifically relates to a calibration method for near-bit wireless short transmission ground environment based on electric field theory. Background technique [0002] In logging-while-drilling and drilling operations, near-bit measurement can obtain real-time bit current position information, thereby depicting real-time drilling trajectory information, so that ground operations engineers can adjust drilling speed and direction in real time and follow the set borehole trajectory Complete drilling operations. The sensor for near-bit measurement is installed between the drill bit and the screw. Due to the special structure of the screw (completely mechanical, it does not have electrical connections such as threading, unless the screw structure is modified), the near-bit measurement unit does not have an electrical connection with the MWD system. Therefore, the measurement data of the...

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Problems solved by technology

However, the wireless short transmission uses the closed-loop electric field in the wellbore mud environment to realize wireless signal transmission. The wellbore environment on the wellsite is harsh, and the actual wellsite experiment operation is inconvenient. It is time-consuming and laborious. At the same time, the test and development costs are high, and it is impossible to realize the different drilling environments of the system. The next test brings great difficulty to the research and development

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