TECHNOLOGICAL ADVANCEMENT IN THE OIL AND GAS INDUSTRY: A CONSIDERATION OF THE NODAL SEISMIC SYSTEM

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Chapter Problem Statement:
To quantify the amount of equipment required of a conventional cabled land system (and therefore what could potentially be eliminated by a cable-free system), let's analyse a typical 4,000-channel seismic acquisition system with receiver-station spacing of 30 meters (plus 10 per cent): Such a system would require 132,000 m. (132 Km) of in-line cable.
This cable would house telemetry twisted-pair wires and, in most instances, power wires. The in-line cable alone would weigh in at 6,000 Kg. Add in the geophone strings (33 m, each with six geophones) for another 132 Km of cable, weighing a bit over 15,000 Kg. Power for the line would typically require some 84 power stations at 58 Kg each for another 4,872 Kg. For our hypothetical 4,000-channel 2D line, we would require some 264 Km of cable and weigh in at around 25,872 Kg, or slightly less than 6.5 Kg, per channel. Add to this the fact that every receiver station would require three connections, two for telemetry/power and one for the sensor, and that each power station would need at least one connection, and the total number of connectors reaches over 12,000. That is a lot of equipment to protect and maintain, and this scenario does not even consider any cross-line requirements for 3D operations.
Even so, weight is not the only bothersome issue caused by seismic cables. Another is pure mathematics. There is either too much cable or not enough, and they must always be cut to specific lengths, or takeout intervals. If there is not enough cable, the project must be redesigned to accommodate the limits of the equipment at hand. If there is too much, extra equipment must be deployed to the field, so that the excess cable can be piled or coiled between receiver stations, which creates an environmental and operational burden, and can lead to seismic noise problems due to leakage.
To further complicate matters, cables are easily damaged by natural and cultural causes, and connectors

Adeolu O. Aderoju is a young and vibrant Geophysicist with his core professional interest in Exploration Geophysics and more specifically Reflection Seismology. He earned his Bachelor's degree in Applied Geophysics from Ladoke Akintola University of Technology, Ogbomoso, Nigeria. His outstanding service record of Student Leadership there also earned him an Award of Excellence (an International Award) from the American Association of Petroleum Geologists (AAPG).

The author has had the privilege of carrying out exploration works on nearly all geologic terrains in Nigeria and a few other international fields. He presently works as a Geophysicist at Geoterrain Nigeria Limited - a geosciences firm with ist base in Nigeria. Being a writer and a blogger as well, he is the author of the fast selling book "Service: a Master Key in LEADERSHIP".