The solution

Launched in 2018, the OD OBN programme is a research and development collaboration between partners Shell, Petrobras, SENAI CIMATEC and Sonardyne, supported under the Research Development and Innovation funding clause of the Brazilian National Agency for Petroleum, Natural Gas and Biofuels (ANP).The On-Demand Ocean Bottom Node (OD OBN) programme marks a pivotal step in addressing these challenges, providing a disruptive approach to time-lapse seismic data acquisition.

It is a pioneering new [system for] acquiring 4D seismic data, which delivers more efficient and cost-effective surveillance of complex pre-salt fields. At its core is a long-term OBN system that can remain on the seabed for several years, capturing seismic data that can be recorded and harvested “on-demand” using autonomous underwater vehicles (AUVs), without the need for repeated deployment and retrieval cycles.

Vast quantities of seismic data are harvested wirelessly using an AUV such as Saipem’s ‘Flatfish’, that implements the through-water optical interface to interrogate the OD OBNs, as developed under a separate ANP programme sponsored by Shell.

This AUV data harvesting approach eliminates the need for node recovery, dramatically reducing vessel time, operational complexity and associated costs.

Key Sonardyne technologies include wireless acoustic communications, required for long range recording control and node clock time offset measurement, and Sonardyne’s BlueComm extremely high-speed optical communications for short range data harvesting to a nearby AUV or remotely operated vehicle (ROV).

The results

Over 2,000 days of trials of pre-production nodes have been conducted across various pre-salt fields including Sapinhoá, Itapu and Buzios. These have successfully demonstrated acoustic control, high-fidelity data acquisition and optical data harvesting using BlueComm, as well as comparing OD OBN data with that of other commercial nodes.

The final round of tests concluded successfully in 2025, with results presented at the IMAGE ‘25 conference in Houston and SBGf Rio’25 conference in Rio de Janeiro.

Next steps

A pilot array of 660 pre-production nodes is currently being produced at a brand-new manufacturing facility in Camaçari, near Salvador, Brazil. Hundreds of these nodes will soon be deployed at the Mero field operated by Petrobras for extended testing and performance evaluation.

The long-term vision is to use autonomy and state of the art communications technologies to enable operators to conduct more frequent ‘on demand’ seismic surveys, with higher fidelity data, at a fraction of the cost of conventional seismic survey methods.

This capability will provide clearer insights into fluid movements and pressure changes within the reservoir, helping to optimise production strategies, improve decision making and enhance recovery rates in one of the world’s most challenging offshore provinces.

OD OBN is not just an incremental improvement, but a fundamental shift in how the industry approaches deepwater reservoir management.

Overview

Our range of subsea floatation collars enable acoustic navigation and positioning transponders to be deployed, moored on the seabed and then recovered to the surface.

The floats are compatible with all our transponders including: Compatt 6+, Compatt 6, AMT 6 and DPT 6. They can be used with directional and omni-directional transducer types.

Manufactured from high performance materials appropriate to the required depth rating, each float assembly comes in two halves and is clamped around the transponder using stainless steel fixings made of super duplex stainless steel.

Bright colours make sure good visibility, either when subsea and viewed from an ROV’s camera, or when floating on the surface prior to recovery.

At a glance

• Use it to recover seabed transponders without ROV intervention
• Choice of shapes to suit application and environment
• Available in 3,000, 5,000 and 7,000 metre depth ratings

We also supply ultra low-drag light bulb shaped float that provide significant reduction of the deflection caused by water currents and dramatically improves the stability of the transponder. The levels of both the deflection and stability directly affect the quality of the achievable positioning. The light bulb float therefore ensures optimum performance from the seabed installed transponders.

The ultra low-drag and highly stable float further allows users to deploy transponders much higher off the seabed increasing the achievable acoustic range. This reduces the required number of transponders enabling life of field positioning without requiring complicated deflection correction methods.

Overview

Compatt 6+ is used for high precision survey and construction operations in all water depths, including: spool piece metrology, pipeline touchdown monitoring, structure installation and dynamic positioning reference.

Compatt 6+ offers significant time saving with fast update rates (up to 1 Hz LBL tracking), all made possible using the Wideband 3 acoustic telemetry protocols. Support of Wideband 2 ranges maintains backwards compatibility. This makes any system operating with Compatt 6+ significantly easier to operate therefore de-risking operations, reducing vessel time and reducing training requirements for offshore personnel.

At a glance

• Compatible with all 6G LBL, INS and USBL systems
• Wideband 3 enabled
• Versatile, flexible and cost-effective
• Over 3,600 different configurations available
• Choice of depth ratings to 7,000 m

Our Wideband advanced signal processing offers improved acoustic performance in challenging conditions, longer ranges, improved multipath rejection around structures and real-time range diagnostics for quality control. Wideband also reduces the interference to and from adjacent Sonardyne and other acoustic positioning systems.

The integrated communications and navigation technology allows the transponder to be used as a multi-purpose modem, autonomous data logger and navigation reference transponder.