How 3D Metrology Solutions Helped ExxonMobil Optimise Operational Efficiency

Project overview

ExxonMobil came to us for support at their Fawley site, which is the UK's largest refinery and petrochemical complex. They requested our specialist knowledge and skills on a large-scale project involving 3D measurement solutions, disassembly, and reassembly of an FCC (Fluid Catalytic Cracking) unit.

The FCC is a critical component in the oil refinery. It enables the conversion of heavy hydrocarbons into lighter, more valuable products, such as petrol, diesel and LPG. This core petrochemical apparatus, vital for optimising refinery operations, requires large-volume metrology and virtual assembly techniques. For Exxon Fawley’s unit, we would need to successfully implement the measurement and setting of the cyclones and the plenum head.

Initially, the measurement was carried out in Gijon, Spain, followed by remeasurement and further inspection at the Exxon Fawley refinery in the UK. This enabled all the parts of the plenum head to be reassembled as accurately as possible over the cyclones. As a result, we could help ExxonMobil optimise project timescales and efficiency, reducing costs and improving operational reliability.

Project objectives

These were the key goals guiding our execution of the Exxon Fawley project:

• Obtain accurate measurements of the cyclones and plenum head, to enable accurate replication in the virtual assembly

• Ensure the integrity and fit of components before physical assembly, identifying and resolving any issues

• Reduce refinery downtime by ensuring a seamless assembly process

• Gain pre and post measurements between the Gijon and Fawley sites

Scope of work

The scope of the project included:

• Preparation and planning: The project required detailed planning of travel to ExxonMobil sites in two countries, along with the scope of work and regular meetings on both sites. In addition to this, we carried out careful preparation for resolving challenges. We set up the Leica laser tracker measurements in numerous positions, utilising 3D scanning and probing.

• 3D scanning and probing in Gijon: The project necessitated full 3D measurement of the cyclones and plenum head, deploying the laser tracker and networking all measurement stations together.

• Data processing: We had to synchronise all measurement data, along with other metrics, using networking techniques within 3D metrology. Other data included measured features, point clouds and STL files for the provided CAD models, enabling analysis for the virtual assembly of all components.

• Transportation and remeasurement: All large-scale parts were to be transferred from the Gijon site in Spain and delivered to the site at ExxonMobil Fawley. We would then remeasure each individual part, ready for assembly.

• Assembly verification: Once all parts were measured and assembled, both virtually and physically, all parts were to be fully inspected in the assembled position.

• Documentation: Throughout the entire process, all data was to be stored and reported back to the customer for full visibility.
  

Our methodology

These are the procedures, tools, and strategies we used throughout the process, using a systematic approach for successful execution of the project.

1. Preparation and planning

• Customer preparation meetings: We facilitated multiple daily meetings with ExxonMobil contacts at both sites. This was to keep everyone fully informed on changing requirements and timescales, communicating site challenges, alignments and other workloads. This would help ensure that the project continued to meet overall strategic aims and stakeholder expectations.

• Equipment selection:

1. Hardware: We used the laser tracker Hexagon/Leica AT960-LR and T-Probe system, paired with both the AS1 and AS1 XL scanners for certain requirements.

2. Software: Industry-leading Polyworks software was used for data capture and virtual assembly.
   

2. Measurement process in Gijon, Spain

• Initial measurements: The 3D measurement process began at the bottom of the cyclone and central column stand.

• Layout of metrology nests: Metrology nests were laid out strategically around the stand, allowing the laser tracker system to be moved around the large-scale networked parts. This would keep all measurements within the same alignment.

• Probing of features: Using the Hexagon/Leica laser tracker reflector and T-Probe, all critical features were captured to enable virtual assembly. This ran from the bottom of the cyclones, along the length to the top.

• 3D scanning: We used the latest Hexagon/Leica AS1 scanner to scan and measure the circumference of the plenum head and outlet nozzles. This was done within the assembled position, relative to the datum alignment.

3. Data processing

• Virtual alignment in Polyworks: We matched our measurement features, point clouds and STL files with the CAD models in Polyworks, for accurate fit and alignment of the cyclones and the head.

• Simulation: We used the aligned CAD model to simulate the assembly of the cyclones and plenum head, checking for fit and alignment error and issues.

• Adjustment recommendations: We made necessary adjustments based on the simulation results, to guarantee a precise fit during physical assembly.
  

4. Remeasurement in ExxonMobil Fawley

• Outlet nozzles remeasurement: We repeated the 3D scanning and probing processes on the outlet nozzles, verifying the dimensions to correspond with inspection drawings and alignment.

• Dimensions for cut lines: We obtained precise dimensions for the cut lines on top of the cyclones. This would allow the plenum head to sit at the correct height once on top of the cyclones, ready for welding assembly.

4. Assembly verification and physical assembly

• Fit analysis: We carried out a final simulation inspection using the remeasured data, verifying that the plenum head fit onto the cyclones.

• Adjustment verification: We confirmed that any recommended adjustments were accurately applied.

• Physical assembly

• Plenum head installation: We monitored the lifting and placement of the plenum head over the cyclones at the Exxon Fawley refinery.

• Alignment verification: Measurement at the final quality control stage verified that the plenum head was accurately aligned to the cyclones. It also needed to be in the correct orientation once installation was completed.

5. Documentation

• Comprehensive reporting: All reports were supplied in a digital format, detailing project-wide alignments and component verification.

• Digital archive: All measured digital data, models, point clouds, STL files and related data were stored in a secure digital archive. This provided a physical backup protecting the whole project, for the security of both ExxonMobil and 3D Metrology Solutions.

Challenges and solutions

These were the key obstacles ExxonMobil needed to overcome, along with the strategies and solutions we implemented to mitigate these challenges.

1. Site coordination

1. Challenge: All information and data, across measurements taken in both Gijon and Fawley, needed to be consistent and accurate.

   Solution: We standardised the 3D scanning and probing procedures across both sites. This was achieved with the same Hexagon/Leica laser tracker measuring equipment and software metrology job files.
   

2. Weather conditions

• Challenge: The team had to protect the machinery in extreme weather conditions, including strong sunlight and high temperatures in Spain, cold and rain in the UK.

• Solution: We scheduled measurements during certain times of the day, during favourable weather conditions. We also used covers to shield the equipment from adverse weather.
  

3. Physical assembly challenges

• Challenge: We had to guarantee that the components fit accurately during physical assembly.

• Solution: We performed virtual assembly and alignment analysis, to identify and resolve any potential issues before they occurred.
  

Key outcomes

This project resulted in several key achievements:

• Effective virtual assembly: The virtual assembly and fit analysis verified that all components would fit correctly before physical assembly, reducing the risk of misalignment.

• Operational efficiency: 3D Metrology Solutions reduced operational downtime for ExxonMobil by addressing potential assembly issues, using virtual assembly within metrology.

• Enhanced technical learnings:  We gained valuable insights into advanced metrology measurement solutions and virtual assembly, in a complex environment and industry.

• Valuable project reporting: We produced comprehensive reports for ExxonMobil, establishing a digital archive of documentation for future projects within the global petrochemical industry.
  

Conclusion

This project demonstrated the profound impact of combining advanced metrology technology, virtual assembly and forward planning. We successfully established this across all stages, from 3D scanning and measurement of the FCC unit in Gijon, to remeasurement at ExxonMobil’s Fawley refinery.

The project also drove precise alignment and functionality of critical FCC components, achieving Exxon Fawley’s project objectives. The effective use of high-precision equipment minimised operational disruptions, during both the inspection process and virtual assembly. It also contributed significant knowledge to the field of industrial metrology and maintenance.

The outcomes of this project showed the importance of detailed planning, accurate measurement, quality assurance, coordination and successful project management. We’re proud to have achieved such impressive results in a highly complex project and industry.