A simplex guided wave communication system using oil industry multi-wire cables Academic Article in Scopus uri icon

abstract

  • © 2018 NDT.net. All rights reserved.The acquisitions of bottom-hole geophysical parameters in cased-hole production oil and gas industry are performed with a minimum disturbance to normal operating procedures. Surface read out measurements can be achieved either in real-time using electrical signals via power line communications or the data can be stored downhole in a bottom-hole instrument and reviewed when it is retrieved later. The latter approach advantages include lower operating costs and a fixed operations schedule. The main shortcoming is the possibility of important operating losses if the bottom-hole recording instrument malfunctions. An alternative is to send periodically acoustic signals via a multi-wire cable indicating that the instrument is operating correctly and sent complementary information related to the recorded bottom-hole parameters. Ultrasonic guided wave propagation though solid metallic structures, such as metal barriers, rods, and multi-wire cables, have been proposed for data transmission purposes. This work presents a simplex guided wave communication system using an Oil Industry Multi-Wire Cable 1K22 MP-35N as a communication channel. The system is composed of a microcontroller based ultrasonic guided waves Pulse Position Modulation (PPM) encoded data transmitter and a receiver instrumentation package made of a data acquisition module, a real-time DSP LabVIEW© based demodulator and a human machine interface running on a personal computer. The system implements a dedicated communication protocol at physical and data links layers, which involves PPM, digital signal processing and HASH byte validation. To evaluate the communication system, the transmitter generated 60 kHz PPM energy packets containing three different bytes and their corresponding HASH bytes. Experimental trials were conducted in the laboratory using cables 1 m and 10 m in length. Results showed that, although a dispersive solid elastic media was used as communication channel, the data transmission system correctly transmitted, received and validated digital information.

publication date

  • January 1, 2018