Underground and ground anti-interference telecommunication method

Abstract

The invention discloses an underground and ground anti-interference telecommunication method. By coding and modulating the current amplitude of a current ring, a communication protocol frame between an underground instrument and ground equipment is coded and modulated to different current amplitudes, and communication between the underground and the ground is achieved; by adopting two stages of error checking, it is guaranteed that a code corresponding to each current amplitude is checked during data modulation, the overall data frame is subjected to error checking during framing and data restoring, and therefore the integrity and correctness of underground and ground communication data are guaranteed; and in addition, a current loop has an interference detection function, corresponding digital filter parameters are automatically adjusted during data sampling by detecting the feature frequency of interference, and interference is removed by filtration before demodulation.

Description

technical field [0001] The invention relates to an anti-jamming long-distance communication method on the underground ground. Background technique [0002] Such as figure 1 As shown, in the commonly used downhole and surface communication methods, there are usually two problems to be solved in the data communication between downhole instruments such as downhole pressure gauges, logging instruments or equipment, and surface equipment: [0003] 1. The problem of interference. When there are high-power power equipment such as electric pumps underground, because the communication cables and power cables between the downhole instrument and the ground equipment are parallel and close to each other, or even in the same cable, the downhole The communication between the instrument and the ground equipment is easily affected by interference, resulting in unstable communication or even communication interruption, and the downhole instrument and ground equipment lose connection; [00...

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Problems solved by technology

[0003] 1. The problem of interference. When there are high-power power equipment such as electric pumps underground, because the communication cables and power cables between the downhole instrument and the ground equipment are parallel and close to each other, or even in the same cable, the downhole The communication between the instrument and the ground equipment is easily affected by interference, resulting in unstable communication or even communication interruption, and the downhole instrument and ground equipment lose connection;

[0004] 2. The problem of communication distance. With the increasing depth of oil and gas wells, the distributed capacitance of communication cables is also increasing. The increase of distributed capacitance will seriously limit the bandwidth of communication cables, resulting in conventional digital communication or high carrier frequency modulation The communication rate of the communication method is severely limited or even unable to communicate

However, the conventional 4-20mA current loop can only realize single-parameter one-way data transmission, which cannot meet the needs of multi-parameter and two-way data communication.

, although the HART protocol based on 4-20mA solves the problem of multi-parameter and two-way data communication, but because the modulation carrier frequency is very low and the modulation amplitude is small, the communication rate and communication distance are limited, which cannot meet the needs of deep well downhole instruments and ground equipment. The requirement for two-way multi-parameter communication between

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