The video quotes Wheatstone's platform manager Mike Watkins, an Australian, who describes the logistics and sequential order of the operation.

"You're dealing with one of the biggest platforms in the world," Watkins said.

"The engineering that goes into this has taken a couple of years at least to get all of these plans together … there's a lot of work in this type of operation.

"To prepare for the load-out, we have to jack the topsides up 20m - so we're jacking a 36,000 tonne structure on four jacking towers up 20m, Watkins' voiceover says as Chevron shows the jack-up operation in time-lapse photography, taking most of a day.

"We lower off the topsides on to the deck support frame and then that combined structure will be loaded out - total weight of nearly 45,000t - on to the Heerema 851 vessel.

We are transporting the topsides at its full height so as we can float above the legs of the SGS (steel gravity substructure) and it's on the open sea to Australia.

Once it arrives in Australia, they'll set up anchor, mooring patterns etc around the SGS, and the barge is then aligned and moved in on mooring lines between the SGS legs, then will be lowered off via ballasting of the barge to its final location until the topside's load is fully taken on the SGS.

Wheatstone project director Chris Miller, an American, said: "When we finish one of these jobs, I think about it in two lights: I think professionally, what have we accomplished?

"But I also think about the team of people that we brought together, and we knew at the end of the day what the platform had to do, how do we want to build it and then, as it's getting built, how do we make sure it gets done safely, the right way the first time.

"So that brings us to today. What a great accomplishment."