The on-demand OBN (OD OBN) development through comprehensive bench and field testing

We present results from an extensive test program of the OD OBN (On-Demand Ocean Bottom Node), from which we have learnt a great deal about this new node’s performance, and which have enabled critical redesign and firmware and software upgrades. Field tests within this program total 1,800 days in deepwater, a luxury only possible because of Petrobras continuous OBN campaign in the Santos Basin. Bench tests range from fit-for-purpose to sophisticated mechanical and electronic tests and simulations, in air, tanks, pressure vessels, etc. Field testing has provided invaluable learnings to complement the bench testing approach. As a result, we have acquired high-quality seismic and geodetic data benchmarked against a commercial OBN; controlled the node remotely and harvested data using acoustic and optical comms by means of an AUV, an ROV and from a vessel; evaluated the housing resilience against transport and handling, and to some extent, corrosion; improved the timing protocol; modified the design to simplify assembly and improve reliability of crucial components; and debugged extensively the electronic modules and battery packs. The latest units are being tested in the Búzios field, while 600 nodes are being manufactured in a new production plant to be deployed in the Mero field in 2025-2026.