10 Jun - ROVs installed and operational
RRS Ernest Shackleton Diary
Position @ 1200: 53°03'North 002°13'East. 25 metres off Leman 49/27/A Platform.
Conditions: Wind NNE x 10 kts; Barometer 1013.9 mb; Air Temperature 11.3° C; Sea Temperature 12.1°C; Cloudy, fine and clear.
Last Sunday saw RRS Ernest Shackleton depart Aberdeen Harbour for the start of the ROV work, with the first task to 'wet test' all three ROVs to ensure that following the mobilisation they would all perform correctly.
Once this was completed, and all was proved to be fine, the vessel then proceeded south towards the West Sole area and the Amethyst Field, some 20 miles to the east of the entrance to the River Humber. The work carried out during the past week has been to survey the legs and risers on platforms and check several underwater structures.
One of the problems with operating in this area is the strength of the tide, which is very strong as a result of being shallow (no more than 35 m). When the current is much more than about one knot it causes problems for the ROVs, which are small in comparison to the work class unit that was used last year, and so much time is spent 'waiting on current', better known in our daily reports to the office as WOC !
On Friday evening, during a period of WOC, RRS Ernest Shackleton broke of from the Amethyst Field and headed towards the River Humber, where we had a rendezvous with Osiris which had been chartered to bring out some spares that were required, along with a selection of newspapers for us to read. This then meant that we failed to keep away from election fever!
With the transfer complete it was back to Amethyst to finish off the survey and then in the early hours of Sunday morning the vessel headed south towards the Leman Field, some 35 miles to the north east of Cromer, Norfolk.
The Amethyst field consists mainly of NUI's (Normally Unattended Installations) and are somewhat stark in appearance with little to see. Leman 27/A is the opposite, consisting of three large platforms, all joined, and dwarfing the vessel. At least they do not have a fog horn blasting out the morse letter U (Dah Dah Dit) every thirty seconds, which could be clearly heard in some parts of the accommodation.
Ernest Shackleton Returns by Dave Sheppard, Client Representative.
It was very nice to welcome RRS Ernest Shackleton back at the beginning of this summer for its North Sea sojourn. It was good to see the same faces from last year. No-one had married a penguin during the intervening period and gone native !
We had to wait until 31 June before taking the vessel for the BP ROVSV cruise but I believe the ship and crew enjoyed carrying out some different tasks over in Norway. The Stolt/BP project involvement with RRS Ernest Shackleton this year is slightly different. Last year we carried out the annual pipeline visual inspections from the vessel. This year we are a bit more stationary for the work, being involved in riser, platform and pipeline tie-in spoolpiece inspection. The main difference is that we are sitting in dynamic position alongside the oil and gas platforms rather than following the pipelines in between. Risers are the vertical pipes that import or export oil and gas up the side of a platform from the pipeline. They are held to the bracings or legs by clamps or guides and are very critical components. At the bottom of most risers a dogleg shaped pipe connects the riser to the pipeline, usually flanged and bolted at each end. This is the tie-in spoolpiece, so called because it ties the pipeline to the riser. The reason for the dogleg shape is to allow lateral and longitudinal expansion of the pipe to prevent buckling. The structural inspection we are carrying out is part of the five year certification programmes that most operators undertake to ensure structural integrity of their assets.
A high point of this years work has been the installation of two brand new Seaeye Lynx inspection ROVs. These vehicles are the first of their type and came straight from factory acceptance tests to the ship. Stolt are hoping for good things from these vehicles as they are likely to become the main vehicle used for inspection tasks over the next couple of years. The vehicles are fitted with a whole host of new and improved features and so far have proved extremely reliable. We also have a Rovtech Seaeye Tiger onboard as a back up vehicle and to be used in areas where access may be too tight for the Lynx. To install all this equipment on the ship meant that we had to build a 22 tonne deck frame to fit over the main hatch. The control cabins for the three ROVs are located on this frame. The launch and recovery systems are spread down the starboard side, with the two Lynx forward of the main crane and the Tiger aft. It all looks very tidy and quite "the business". We have utilised the dry lab for the survey and inspection departments. In here we have a team who are producing diveplans, controlling the work, co-ordinating the ROV`s during the actual inspections and producing reports for each asset.
We also have specialist companies onboard, carrying tasks crucial to the understanding of what is happening to the subsea components of the platforms. These are Subspection, who deal with the cathodic protection of the structures and ICI Synetix, who are responsible for the flooded member detection. The Cathodic Protection (CP) of the platforms is crucial to achieving the design life of the structures and monitoring of the potentials is vital to ensuring that the CP system is working properly and to give advanced warning of when remedial work will be needed. The flooded member detection is carried out to ascertain if any members contain water. If they were designed to be dry and are now flooded, it indicates that there is a crack or defect allowing seawater ingress. Flooded members are noted down and the information passed back to the shore, where they are included in a diving programme for further investigation.
The vessel is the same as always. We have two personnel onboard who are new to the offshore life. I am a bit sorry for them because they are starting at the top. Life in the oil patch doesn't get better than RRS Ernest Shackleton and everything for them after this will be an anti-climax.
We are now 11 days into the work and all a few pounds heavier, thanks to the excellent food that turns up every few hours. I know it's wrong but it's a shame not to eat it after all the trouble taken to prepare it!
Still, I`ll start the diet tomorrow.......
Forthcoming events. Continue survey of platforms and manifolds. Charter personnel crew change by helicopter later in the week.