Bidirectional wireless electromagnetic transmission device and method for well-ground signals of cased well

Abstract

The invention discloses a cased well ground signal bidirectional wireless electromagnetic transmission device and a cased well ground signal bidirectional wireless electromagnetic transmission method, and belongs to the technical field of oil-gas field development. When underground data are uploaded, an upper short section I serves as an electromagnetic signal receiving short section, and a lower short section II serves as an electromagnetic signal transmitting short section; when the TM wave transmitting antenna in the short section II generates an alternating magnetic field in the magnetic core through alternating current, the magnetic core on the short section I of the electromagnetic signal receiving short section can capture the current signal so as to upload the signal; similarly, when ground data is downloaded, the short section II serves as an electromagnetic signal receiving short section, the short section I serves as an electromagnetic signal transmitting short section, and when the TM wave transmitting antenna in the short section I generates an alternating magnetic field in the magnetic core through alternating current, current signals are captured in the short section II to complete signal downloading and bidirectional signal transmission between the short section I and the short section II. Compared with the prior art, under the condition of the same transmission distance, the received signal amplitude is larger, and the carrier frequency is higher.

Description

technical field [0001] The invention relates to the technical field of oil and gas field development, in particular to a bidirectional wireless electromagnetic transmission device and method for casing well ground signals. Background technique [0002] In the process of oil and gas field development, the well-ground two-way operation used for reservoir fluid property parameter monitoring and downhole monitoring and control instruments and equipment all depend on the establishment of well-ground two-way communication channels. For example, layered mining has been widely used in modern oil and gas field development and production. The production process monitoring of split-layer fracturing or post-layered water injection as well as oil and gas production requires real-time understanding of the status data of reservoirs and downhole equipment to provide reliable and real-time decision-making basis for development and production management. and oil and gas well management. [0...

AI Technical Summary

Problems solved by technology

[0005] The existing technology relies on the ground to form a closed loop to complete the signal transmission. This method is faced with the problem of signal transmission brought about by changes in the electrical parameters (conductivity, dielectric constant and magnetic permeability) of the formation (different wells, different production cycles of the same well). Unstable, usually due to the flow of formation water, the communication is abnormal for a certain period of time and the communication in area A is normal, but the communication in area B is not possible due to different formation parameters, and the versatility is not strong

[0006] The existing technology relies on the ground to form a closed loop to complete the signal transmission, because the transmission depth of the electromagnetic wave in the formation is determined by the skin depth δ of the electromagnetic wave in the formation, and the skin depth (ρformation conductivity, f operating frequency), therefore, in order to achieve a deeper telemetry distance, an extremely low frequency (0.1Hz-10Hz) carrier is usually used for data transmission, which leads to slow data transmission rate and low efficiency

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