Offshore Oil and Gas


Spool Metrology

Measure in 3D, Manage in 4D
Our entry into the Offshore Oil and Gas market was focused on providing a precise, accurate, 3D data collection solution that leveraged the differentiating features of subsea LiDAR (SL) technology to provide cost-effective, quality spool metrologies. Since the first open water commercial test conducted in Q1 2014, the SL1, SL2 and SL3 laser systems have completed over 300 metrologies worldwide.

Subsea LiDAR data sets provide a variety of 3D intelligence beyond metrology.  Installation contractors recognize time, cost and performance efficienceis across thier projects using subsea LiDAR data. Clients with a long-term view on true data value recognize that subsea LiDAR precise, accurate, repeatable, 3D point clouds provide an additional level of insight into long term asset integrity. (That is why we can be found in IMCA approved guidelines.)

Each of our metrology engagements leverage the unique features of subsea LiDAR (SL) technology to deliver the most advanced method to measure subsea distances and define positions in the 3D (XYZ) plane. Following best practice guidelines from terrestrial LiDAR applications, 3D at Depth's innovations have expanded the capabilities of underwater lasers to satisfy geomatic construction surveyors and engineers. The non-touch approach and measurement repeatability at longer ranges, enables metrologies to be undertaken on existing Jumpers without the need to shut in the production operation and reduce the nonproduction times of wells.

From project planning to final reporting, the repeatable workflow, increased survey efficiencies, and reduced vessel time, have generated the support of oil majors and small independent operators. 


Increasing the ‘I’ and reducing the ‘MR’ by collecting spatially correct millimetric point cloud data for a digital twin model.

Baseline datasets of both ‘Static’ and ‘Dynamic’ Subsea LiDAR Laser can be merged into precise 3D models of infrastructure, seabed, spools and pipelines. These models can be used to measure accurate distances, angles and volumes. Asset managers, LoF managers and subsea engineers are able to visualise an exact digital twin of the subsea offshore asset. 2D charts are now a redundant deliverable. 3D digital copies of the offshore subsea infrastructure reduces interpretation, reduces mistakes and allows cost effective and precise repair solutions.

Seabed structures and connecting infrastructure can be captured at installation or at any specific time and that spatial relationship between structures and seabed is preserved at that point in time.

4D temporal data collected year over year can be used to precisely determine any differential settlement between drill centre structures, pipeline out of straightness, pipeline ovality and the volume of any scour, over time. Annual datasets can be viewed simultaneously using colour as differentiation, making changes easy to locate and then measure. 

Exact location of flying leads can be recorded and bend radius measured. Anode depletion rate can be calculated by measuring anode volume. Centreline splines can be fitted to any pipeline, riser or spool to calculate precise bend radius. These splines can be exported to CAD or Finite Element Analysis (FEM) software packages for further analysis.


Inspection, Maintenance and Repair (IMR)

Increasing the ‘I’ and Reducing the ‘MR’


Long Term Asset Integrity and Reliability
The challenge of Offshore oil and gas production facilities to monitor, measure and evaluate issues of vibration and noise across an asset’s life cycle are greatly reduced by having the right kind of accurate, precise and measurable 3D data to use in analysis. Long term asset and field integrity, and reliability issues can be solved at the start of the 3D data collection survey process by using subsea LiDAR (SL) laser technology.

The unique features of 3D at Depth’s subsea LiDAR SL systems provide a controllable beam that enables users to scan assets in 3D using the structure/area on inverters.  Users can select and control the LiDAR beam to dwell on points of interest within the scan measuring time stamped vibration from 1 to an infinite number of selectable locations once, or on repeat measurements until told to stop measuring. The feature allows a touchless measurement to the obtaining rate of the sensor at the worksite location. Post collection outputs can be analyzed and reported linear and rotational information as well as vibration measurements up to 20kHz. The scan is made up of  2.1 million measurements per sector to provide highly accurate 3D LiDAR point cloud data which can be measured, analyzed, and exported into any existing GIS systems, CAD based platforms or via 3D at Depth’s LiDAR  Immersive Collaboration Platform. 

Subsea Leak detection is traditionally done optically using dyes or black light detectors, which are camera based.  This type of technology approach is not able to undertake any other task while searching for suspect leaks. (Detecting cameras generally offer a narrow field of view which generally ranges to around 5m limiting the search efficiency). With the subsea LiDAR (SL) optical design, infrastructure and pipe integrity leak detection surveys can now achieve greater 3D point clouds to Inspect, evaluate, monitor and proactively intervene with near real time data.  The SL1, Sl2, SL3 optical design has proven in active well centers the detection of production fluids. The unique subsea LiDAR capabilities provide reflectivity and deliver operational performance with a longer scan range – up to 45 meters.  

While mapping statically or dynamically using Subsea LiDAR, the customer can generate 3D measurable point clouds simultaneously undertaking leak detection inspection hazards. Collected data will also generate a useable field map (link to field mapping section). To increase performance the operator should include a milky colored dye into the production or commissioning fluids such as Mono-ethylebe glycol (MEG), Hydraulic production control fluids Oils, or fluids utilized while “pigging” or gels used for hydrostatic testing, condensate removal, dewatering, internal pipe debris removal then the our SL subsea LiDAR scans can instantly pick up the reflectivity difference for faster decisions.

Leak Detection

Field Mapping and Asset Inspection

Most subsea infrastructure installation requirements require positional information and interpretation from an ROV camera or from acoustics measurement solutions which provide low data points. These results are then transposed from online navigational “fixed” locations into a chart drawing and then issued. This data set allows minimum compliance requirements in many cases, but not the information needed for operational awareness especially for the engineers tasked with the challenge of keeping the assets operational. 

Subsea LiDAR field mapping using our Dynamic LiDAR solution enables a fast, highly detailed 3D map with geolocated assets that pinpoint interconnecting cables and hydraulic lines. Static scanning , undertaken while the ROV settles on the seabed, allows for very high resolution inspection for ovality, collision dents/cracks identifying early signs in potential infrastructure failures. The ability to blend dynamic and static scans offer a single data set for change detection over time to take place for total area management. The 3D data sets from the Dynamic LiDAR scans export in conventional chart formatting, as well as offering detailed information on assets, seabed and other structures. These scans are collected at altitudes of around 15-20m above the seabed (or higher if needed), providing a low risk operational data collection process. This flexibility on scan altitudes help  keep the vehicle out of harm's way from pressurized assets containing environmentally sensitive fluids.

3D at Depth has several proven fast data collection methods for identifying leaks of production or commissioning fluids, while in motion over well and manifolds. This capability provides the potential for early signs of failure awareness or delayed startup commissioning rather than the more serious failed pressure test. 

Many operators have adopted the practice of performing dimensional control surveys on their assets on land before they deploy subsea. Dimensional control surveys include high accuracy measurement of structures using a combination of key features and survey targets. The surveys are typically completed using total stations, laser scanning or a combination of the two methods and provide a method for developing a 3D model of control points after fabrication.  These surveys are particularly useful for determining the relative locations of two or more structures and their associated features.

3D at Depth have developed best practices for performing dimensional control surveys for subsea assets for use in spool metrology and life of field applications. Subsea survey targets allow for the ability to locate key features such as hub faces and headings (flanges for horizontal spools). In many cases, the structures are deployed and then integrated with protection frames which obstruct the actual flange or hub locations. The DC control points can be then used to derive exact feature locations.

In life of field applications where spools have been installed, the targets allow operators to survey these structures and easily locate their hub locations.

In this example, a dimensional control survey was performed on a PLEM including several survey targets, feature locations and hub headings. Years after deployment, the operator was able to laser scan the structures and measure the change in location of the hub interfaces although these hubs were not visible.     

Dimensional Control for Subsea