HOIS publishes drone based inspection guidance

Did you know that unmanned aerial vehicles (UAV) or systems (UAS), often known as drones, are now being frequently used with on-board cameras to carry out external remote visual inspection (RVI) of oil and gas facilities? The advantages of this approach, compared to a visual assessment by an inspector, include:

• Ability to obtain images of inaccessible areas e.g. flare tips in operation;
• Ability to capture digitally and record with positional information;
• Storage of the image allows comparison with subsequent surveys;
• Ease of transmission of the images around the world via the internet for assessment in a remote (comfortable!) location.

HOIS identified that there were no technical standards nor guidance available regarding the minimum acceptable UAV image quality, nor the optimum imaging equipment to deploy on these devices. As a result, wide variations in image quality arose from different UAV surveys with no criteria to assess whether the images were fit for purpose.

To address this gap, HOIS organised trials, performed by its members using airborne UAVs, to inform the development of a document which gives guidance on image quality and covers usage of UAVs for external RVI within the energy industry. The aim of the document is to ensure that the minimum image quality achieved by UAVs is adequate for the intended purpose of making engineering assessment of the integrity status of the parts inspected which can then be used to assess fitness for continued operation.

Detailed guidance is given with respect to three UAV RVI applications of highest priority to HOIS members:

• Generation of UAV images having a resolution equivalent to close visual inspection;
• Coating assessment to ISO 4628;
• Flare tip/stack inspection.

The guidance document is now being made publicly available (rather than remaining confidential to HOIS members) so that there can be a more consistent approach to the use of UAVs with on-board cameras for RVI of oil & gas facilities. It can be downloaded from www.hoispublications.com.