Abstract
Active seismic surveys, for the exploration of oil and gas reservoirs, are conducted using a huge network of geophone sensors (>10,000) covering a very large area and interconnected using seismic cables. Such cables enable reliable operation and fast data transfer, but account for a major percentage of the survey cost and limit its flexibility. In this paper, a wireless seismic data acquisition system that provides real-time data transmission for active seismic surveys is designed and implemented. A system that comprises a smart wireless sensor node and a gateway unit is demonstrated as a proof-of-concept. The smart wireless node comprises a geophone sensor, a high-resolution data acquisition system and a smart reconfigurable wireless communication module. The data acquisition system includes an electronic circuit for amplification and filtering, a single-board computer and a 24-bit analog-to-digital converter (ADC). The wireless communication module comprises a 2.4 GHz radio frequency (RF) transceiver connected to a pattern reconfigurable antenna. A microcontroller is employed to reconfigure the Yagi-Uda antenna to scan its radiation pattern in different directions and focus the radiated power in the direction of the nearest gateway. This high-gain directional antenna would allow communication between the sensor node and the gateway over a longer distance as compared with the monopole antenna conventionally employed in commercial wireless seismic systems. The proposed system, employing a reconfigurable antenna in the sensor node, has been implemented and tested and was able to successfully capture seismic data from the geophone sensor and transmit it wirelessly in real-time to the gateway unit, achieving a notable 25% enhancement in the communication range between the sensor node and the gateway. This communication range enhancement results in a significant 56% enhancement in the gateway's communication area coverage, when compared to similar systems that use conventional monopole antennas in their sensor nodes.