How did Saudi Aramco perform this major lift at Fadhili gas plant?
By Mustafa Al Abdulmohsin17 October 2021
Early 2021 saw a critical lift performed at the Fadhili gas plant in Saudi Arabia when a reboiler tube was removed for inspection. Mustafa Al Abdulmohsin reports
The newly constructed Saudi Aramco Fadhili gas plant in the Eastern region of Saudi Arabia, is capable of processing up to 2.5 billion SCFD (standard cubic feet per day) of natural gas both from land and sea reservoirs.
The removal lift of the reboiler tube in March 2021 was performed by the Transportation & Equipment Services Department (T&ESD), the organisation responsible for lifting services at Saudi Aramco’s hydrocarbon facilities.
This reboiler is designed to reheat the amine solution that is used in the gas treatment process. Each reboiler is capable of processing nearly 3,000 US gallons per minute of amine solution. Amine gas treatment, also known as amine scrubbing, gas sweetening and acid gas removal, uses aqueous solutions of alkylamines (amines) to remove hydrogen sulphide and carbon dioxide from gases.
The equipment needed to be removed so the internal components could be inspected for their integrity and assess any damage as it had been in operation for a year.
Terex Demag AC 200-1
The crane used for this lift was a 200 tonne capacity Terex Demag AC 200-1, with 34.4 tonnes of counterweight. It was positioned to lift at a 10 metre radius and was configured with a total boom length of 37.9 metres at a 72 degree angle. Capacity in this configuration was 47 tonnes.
The reboiler was at an elevation of 18 metres. Load net weight was estimated to be 22 tonnes. With the additional load of slings, hitching and other below the hook rigging tools, including the extraction machine, the total load weight was estimated to be 39.5 tonnes), around 84 per cent of the crane’s capacity.
The first lift was to remove the outer shell attached to the main reboiler body, which processes the inlet and outlet product as well as protecting the internal tubes. After that, the tubes were removed using a special tube puller. Quite a complex task, this special lifting device extracts the tubes with a horizontal force and slowly pulls them through the main shell. The device itself is heavy, especially when compared to the load, making the lift a considerable challenge. Moreover, the vertical load on the crane gradually increases during the extraction, adding more weight on the pulling machine, meaning the centre of gravity is continuously changing during the process. Balancing of the load must be very precise and is controlled through a specialized chain system to minimise the vertical line movement.
Saudi Aramco hydrocarbon facilities
Safety is a top priority and this lift required a highly trained and specialized rigger to safely direct the operation. All lifts on site start with evaluating the environmental conditions and a critical lift plan is created, reviewed and approved.
Similar lifts are conducted on a daily basis across Saudi Aramco hydrocarbon facilities. The company has standardised its lift plans so there is a comprehensive check list to work through for each lift which analyses all requirements, including the load weight, crane configuration, additional below the hock loads, rigging type and information, other environmental and site checks such as ground and windspeed requirements as well as the total crane capacity in comparison with the load weight.
ABOUT THE AUTHOR
Mustafa Al Abdulmohsin is a heavy lift engineer who has been working at Saudi Aramco for more than 10 years. His experience focuses on managing different equipment services, primarily mobile cranes which provide lifts for Saudi Aramco oil and gas plants.