Development of a novel seismic acquisition system based on fully autonomous ocean bottom nodes

It is now established that ocean bottom node (OBN) surveys provide superior seismic data compared to traditional towed streamers, but deployment of the nodes is time-consuming and expensive. As an alternative, we are developing a novel seismic acquisition system that utilises a fleet of fully autonomous underwater vehicles (AUVs) as OBNs. The objective is to eliminate the reliance on remotely operated vehicles (ROVs) or ropes for deployment, making ocean bottom seismic acquisition significantly more efficient and cost-effective. To succeed, several criteria need to be met, including recording of good geophysical data, system affordability, low power consumption, units’ ability to act autonomously (e.g. steer, land, listen, re-position, surface) and to respond to remote commands (e.g. cease activity, return), a failure recovery protocol, automated deployment and retrieval, and system-wide communications. The ability to record good seismic data was assessed in October 2022, when we performed active-source seismic field trials in the UK. Five AUVs were deployed adjacent to commercial nodes (all units carried identical geophysical payloads) and a series of 2D lines were acquired at varying orientations. Analysis of the data confirmed that our units achieved satisfactory coupling with the seabed. The unit’s in-water capabilities were assessed during multiple field trials in 2022 and 2023, offshore UK and Australia. Tests consisted of simulating seismic acquisition cycle (flights, landings, take-offs and repositioning) where it was verified that missions were reliably executed, including landing within 10 m from pre-planned locations and recording good quality passive seismic data.