I work in the subsea oil and gas industry, exploration and production. I used to work as an inspector for on of the majors, then went to work for an umbilical manufacturer in the Project Management group. Ended up going BACK to for the major, as an inspector. I spend probably 95% of my time on land, and a few weeks a year TOPS offshore. I have mostly dealt with umbilicals and control systems in my career. A lot of welding and fabrication, a lot of high pressure testing, and a lot of electrical and fiber optics work. I dont have any overly interesting pictures I can share, but I can post a picture of an umbilical.
I've been to what was (not sure if it still is) the deepest spar in the world. It was quite a massive structure, and it was a loooooong ways out there in the gulf. I've also been to a brand new TLP that we installed the first umbilical on.
Umbilicals are used to provide hydraulic controls, chemical injection, electrical power and signal, and fiber optic between the platform and the well subsea. They are typically a few miles long, and have anywhere from 15-25 tubes, 2-6 electrical cables, and 2-4 fiber optic cables. The tubes are mostly SAF2507 (UNS S32750) Super duplex stainless steel. All welding is tig with 100% X-ray and zero visible indications for acceptance criteria.
The one pic shows the cut end of an umbilical. It is filthy, as it is part of an old sample that was laying outside at the shop. We were using it for some trials. The other is what a typical topside termination would look like. The tubes will get tied in to the HPU offshore to provide the hydraulic controls/chemical injection, and the electrical cables/fiber optic cables will get tied in to a junction box. I've got a few more I can post but I need to resize them.