IATEC Plant Solutions Inc. introduced drone photogrammetric survey to Petrobras, one of the largest oil and gas companies in the world, as a new method for surveying the change of engineering data assets after multiple plant upgrades…

Project Background

IATEC Plant Solution was founded in 2000 and is a technological solution provider for the engineering and construction (E&C) industry. In the Power & Process business line its services cover all phases of a plant life cycle:



– Evaluation of the conception, providing expert consultancy


– 3D layout analysis and review


– Concurrent auditing in order to find out problems immediately during construction


– Project updates after construction (as-built) and during upgrades


– Industrial Asset Management  during operations




In 2016, a Petrobras gas treatment plant in Brazil, part of one of the largest oil and gas companies in the world, found itself stuck between two inspection methods after several plant upgrades. They needed a way to bring their engineering data assets (i.e.: 3D models, drawings, databases) up-to-date, but laser scanning was considered too expensive and direct visual inspection too risky and time-consuming. In search of another alternative, they asked IATEC Plant Solutions Inc. to develop one.


IATEC Plant Solutions Inc. introduced aerial photogrammetric survey via drone and ran a pilot project to prove its efficiency. In only three working days, a DJI Inspire 1, automatically driven by Pix4Dcapture flight planning application, collected a total of 2588 nadir and oblique images (nadir taken with grid mission and oblique with free-flight mission) from 10 sub-areas of the facility. In order to determine the best processing option, the images were processed in different software to check for quality, speed, accuracy, flexibility, configurability and usability. Gradually Pix4D emerged as the leader and was used from then on.

The main objective of this project was to develop a field surveying method for large-scale industrial asset management that would be cheaper, faster and more precise than traditional methods. The results proved more efficient and economic than previous methods, providing impressive accuracy and models that overlaid perfectly with the existing 3D design.

*Industrial Asset Management refers to the system on an industrial plant charged with protecting and increasing assets.





Survey Methodology

1. Direct Inspection: (Difficult Access, Life Risky, Time Consuming)



To send personnel for direct visual inspection is extremely time consuming. The workers are exposed to life-risky conditions such as falling or explosion when climbing up and down the structures with a harness, and due to the complexity of the plant structures, it is difficult to access to all areas of interest. This traditional method not just costs a lot of time but is often considered low-quality. Manual errors could occur on field handbooks, and to redo the survey will take almost forever.


2. Laser Scan: (High Precision, Expensive, Heavy Data Load, Location Restricted)




Laser scan has been one of the most used methods for the past few years due to the precision of measurement it achieves and the shorter time it takes compared to traditional field survey. However, it still requires personnel to remain in risky areas for weeks or months. Laser scan has limitations in measurement distortions and positions shifts as distances increases (because the technology is non-stereoscopic) and heterogeneous cloud density (too many point for regions close to the scanner but too few points far away), which causes burdensome processing and handling issues. The heavy load of the files resulted in small volume of processing, and the frequently occurred software errors lower the overall productivity.



3. Aerial Photogrammetric Survey: (High Accuracy, High Efficiency, Safe, Low cost)




IATEC Plant Solutions Inc. developed the photogrammetric surveying method to Petrobras due to its low cost, high accuracy and simplicity. In order to achieve the best surveying results during a week of time when the plant was shut down, we planned ahead and picked the optimal drone, processing software, and the computing and storage resources. 750,000 square meters were successfully reconstructed within just 3 days using this new drone photogrammetric technology.



Overlay of the Pix4Dmapper 3D point cloud and the existing CAD design




Project Execution

Optimal flight plan

Before actually going on site, it is critical to target which part of the plant to map and the number of layers that each region needs to be mapped to have the entire project done within the scheduled time. The figure below shows our mapping plan based on the complexity of the structures:




Hardware – a DJI Inspire 1 + an iPhone 6S


For this project, we chose DJI Inspire 1 to collect images, videos and telemetry files because the Inspire 1 is the most affordable professional-grade drone in the market. It is extremely easy to fly, stable in windy conditions and extremely portable. Quality photos captured using the 12 Megapixel onboard Zenmuse X3 camera, combined with accurate telemetry data from both GPS and GLONASS satellite systems played an important role in the final success of this project. The use of the free Pix4Dcapture app, which is compatible with DJI SDK, enabled the Inspire to automatically fly routes that are optimized for mapping. A week before the project execution, Pix4D just launched the iOS version of the application, so it was a great timing for us to give it a try.




Software – Pix4Dmapper

We processed the images using 4 different software and eventually picked Pix4Dmapper as our preferred one. One of the software generated better orthomosaic than Pix4Dmapper but the point cloud and 3D model were much worse, and it took up to 3 days for processing a sub region while Pix4D took only 3 to 4 hours.



(Left) Direct precise measurement in Pix4Dmapper (Right) Changes noted on the new-generated orthomosaic

The features we especially like in Pix4Dmapper are flythrough videos, compatibility to our existing CAD/CAE tools, and configuration settings. The new rolling-shutter effect correction in the latest version improves the accuracy. Pix4D software provides very impressive results with easy (and very few) manual intervention in a short processing time.

Final Results



Project results surprised both our team and PETROBRAS-UTGCA. Not even in our best projections we could imagine that the whole work would proceed so fast and so smooth as it happened. The orthomosaic generated for each sub-region and the original images proved a precise way to highlight engineering document inconsistencies.


The 3D reconstruction showed a fast way to check for plant detail which was never displayed in the 3D project models and 2D drawings. The Pix4Dmapper photogrammetric 3D point cloud can be imported into 3D review tools such as Autodesk Navisworks and compared to the existing 3D models in order to show inconsistencies, rearrangements and displacements.



Future Preview

In the near future, IATEC Plant Solutions plan to apply the new technology for regular updates. More studies and trainings will be executed to achieve a complete 4D data storage and simulation.    


  1.    Expansion design and construction planning
  2.    Environmental assessment
  3.    Safety studies
  4.    Concurrent construction auditing
  5.    Operation and Maintenance Crew Training
  6.    Real-World virtual Reality walk-through and 4D simulations
  7.    Thermal mapping for heat concentration monitoring to analyze the risk of explosion.



Special thanks to all project partners-

Alisson Cardoso Gomes da Silva, Rafael Agostinho, José Marcos Borges Franco, Ailton C. Mendonça

IATEC Plant Solutions Inc.:
Luciano Araujo, Henrique Marques


View Project Video HERE