Remote Metrology

Remote Metrology

How is equipment interfaced remote onshore?

Equipment interfacing is performed by the ROV crew on-board the vessel or rig through instruction provided by the onshore metrology team. Typically, on a large campaign ROV crews will be provided the option of a C-PINS interfacing course before the first remote metrology. But in reality, it’s quite simple. C-PINS requires just a single serial channel (24V, RS232) to the surface from the ROV; no fiber splicing is required. This makes the equipment spread essentially a plug and play solution for the ROV to install. Pictures or video of the mobilized ROV are sent back to Houston where the onshore metrology team confirms the cabling is properly secured and the C-PINS is stowed safely for deployment.

How do you communicate with clients without personnel offshore?

Client liaisons another area where we have found great benefit in being onshore. The client can be in the control room with us, offshore on the vessel/rig, or in their office onshore. As with any of our manned metrology work – we have a client reviewed and agreed task plan. Just like calling up to a vessel supervisor from the ROV van – we can call the same supervisor from the control room to keep them abreast of where we are in our operations.

How is data controlled and collected? How is quality of data ensured?

Real time QC is a great question and my answer ties into the next question about data transfer. We are controlling and collecting the data on a laptop in the control room onshore. We are looking at SD’s and data quality as we take the fix. We know how good the data is as we are collecting it. We focus on this with our surveyors to make sure we move on to the next section of the task plan once we have the data needed to fulfil the specification. We do not collect excessive data – just in case. The raw data that a client would want to QC (the OpLog in our case) can be made immediately available across the table or via email to anyone that wants to QC the data. I have just looked at a full metrology oplog from 2 weeks ago – the file size is 65KB. Many of our clients have built their own macros for automatically importing and populating their QC spreadsheet.

How is data transferred remotely?

As described above during our remote metrologies, C-PINS is fully controlled from onshore. We have full two-way (Tx/Rx) serial communication with the C-PINS on the ROV from the laptop onshore (data rate is 38,400bps to the C-PINS on the ROV). The survey data is not transferred from offshore but collected in real time from the C-PINS to the data acquisition laptop collecting the metrology data onshore. This brings us back to the QC component of your question. We don’t wait for data to come back from offshore, we are collecting it onshore and performing the same real time QC that we do on our manned metrology operations. We have the same control over C-PINS onshore that we do sitting in the ROV control van.

How does it compare to a manned metrology?

With no personnel onboard and the equipment on a lump sum cost structure, it is significantly less expensive to go with the remote solution. Another major benefit is that the cost of the remote metrology is known in advance. The original estimate used by the client for the metrology costs will be consistent and never vary, as the rate is lump sum. The client will not see any unexpected day rates from delayed scheduling or personnel being offshore longer than expected.

How many free days does a client get to complete the metrology?

The short answer is, US Gulf of Mexico metrology work has a 15-day dock to dock equipment allowance. The pricing for international remote metrologies allows for a 30-day window for each metrology.

What happens if a metrology takes multiple days to complete?

No problem as long as we do not exceed 48hours onshore online support per metrology. This includes all interface checks and data collection. Our lump sum pricing means that if you perform half of a metrology on one day, and the second half the next day, the cost is the same. This exact scenario was seen on our last remote metrology in the Gulf of Mexico where bathymetry depth data was collected for a few hours on Day 1, and the C-PINS metrology data was collected on Day 2. If the ROV has issues and we are taken off line – we will demob the shore team until they are ready for us to continue with the work. This method of working means that the client does not need to up-man the ROV crew from 12 to 24 hour operations just because of a metrology. With daily rates of equipment and personnel no longer a factor, gone is the need to hurry through the job and demobilize before another day rate is charged. If the metrology being performed is not on the critical path, the flexibility for 12-hour ROV operations is a real cost savings.

Contact us with more questions or email sales@zupt.com for lump sum metrology pricing.