Position reference sensors (PRS) in dynamic positioning systems have either been global systems, such as GNSS, or targeted local PRS, such as laser, radar, or taut-wire. Local PRS operate by placing an artifact into the environment and tracking that. For a laser or radar local PRS that artifact is a reflector or a responder. For a taut wire that artifact is a heavy weight. Once this artifact is in position then the sensor tracks where it is relative to the artifact.

This method of operation, where an artifact is tracked, is understood throughout the DP industry. Targetless local PRS disrupt this as the system no longer relies on targets placed within the nearby environment, but on the environment itself. They may rely on self-mapping technologies or they may be looking for specific structures or features in the environment. These both result in a method of operation which may hold surprises for one trained in traditional DP sensors.

This paper discusses the nature of the changes and what a DPO should be aware of as they approach the use of these sensors. We will also look at particular scenarios where this new operating paradigm will convey particular advantages to the user.

Keywords:
subsea system, dpo experience, targetless local position reference sensor, sensor, Scenario, Upstream Oil & Gas, scene reference point, rig, artifact, society of petroleum engineers
Subjects:
Offshore Facilities and Subsea Systems, Information Management and Systems
Copyright 2018, Society of Petroleum Engineers
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