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This work presents the proprietary design and implementation of a lead zirconate titanate (PZT) sensor for simple digital transmission and reception of guided waves using a high-temperature and corrosion-resistant multiple-wire 1K22 MP-35N cable as a communication channel. These cables are commonly used in the hostile oil and gas borehole environments of the petroleum industry. The sensor design involves electrical/mechanical coupling, instrumentation and casing. The PZT guided wave transmitter instrumentation includes a microcontroller-based pulse position modulator, a signal booster, a PZT-5H crystal and a 9 V battery. The receiver sensor consists of a PZT-5H crystal, an amplifier and a real-time digital signal processing (RT DSP) and data acquisition module connected to a personal computer. Dispersion curves were obtained using Disperse software and a simplified model of the cable. Dynamic linear 3D finite element modelling of the sensor was performed to support the correct frequency selection. To evaluate the sensor design, the transmitter generated 60 kHz guided wave pulse position modulation (PPM) energy packages. Experimental tests were conducted in the laboratory using 1 m and 10 m cables. The results showed that, although there was significant dispersion and there were multiple mode excitations of the transmitted pulses, the system correctly identified 10-bit frames of guided wave PPM-encoded information.

Alternative wireless data communication systems are a necessity in industries that operate in harsh environments such as the oil and gas industry. Ultrasonic guided wave propagation through solid metallic structures, such as metal barriers, rods, and multiwire cables, have been proposed for data transmission purposes. In this context, multiwire cables have been explored as a communication media for the transmission of encoded ultrasonic guided waves. This work presents the proprietary hardware design and implementation of an automatic data transmission system based on the propagation of ultrasonic guided waves using as communication channels a high-temperature and corrosion-resistant oil industry multiwire cable. A dedicated communication protocol has been implemented at physical and data link layers, which involved pulse position modulation (PPM), digital signal processing (DSP), and an integrity validation byte. The data transmission system was composed of an ultrasonic guided waves PPM encoded data transmitter, a 1K22 MP-35N multiwire cable, a hardware preamplifier, a data acquisition module, a real-time (RT) DSP LabVIEW (National Instruments, Austin, TX) based demodulator, and a human-machine interface (HMI) running on a personal computer. To evaluate the communication system, the transmitter generated 60 kHz PPM energy packets containing three different bytes and their corresponding integrity validation bytes. Experimental tests were conducted in the laboratory using 1 and 10 m length cables. Although a dispersive solid elastic media was used as a communication channel, results showed that digital data transmission rates, up to 470 bps, were effectively validated.