Page 21: of Offshore Engineer Magazine (Sep/Oct 2014)

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Analysis

Rig stats

Worldwide

Rig Type Total Rigs Contracted Available Utilization

As an example, Hetherington cites an area high up the HSE’s

Drillship 105 98 7 93% importance list; safety critical elements (SCEs), such as emer- 425 381 44 89%

Jackup gency shutdown valves (ESDVs). An ESCV will be periodically

Semisub 191 162 29 84% tested, and if it meets performance criteria, it will continue to be 33 24 9 72%Tenders used. Under a binary decision making system, its performance, 754 665 89 88%

Total or the time taken to close correctly, could have lengthened from

Gulf of Mexico the 8secs it was designed to close at, to 12 and then 18secs, but

Rig Type Total Rigs Contracted Available Utilization still pass its performance acceptability criteria, a phenomena

Drillship 30 29 196% described as “normalization of deviance” by the KP4 report. 93 78 1583%

Jackup

Another example is water pressure in a dousing system. If the 28 23 582%

Semisub pressure is falling year on year, it could be a sign it is silting up,

N/A N/AN/A N/A

Tenders but it could still pass the binary decision test, Hetherington says. 151 130 2186%

Total “If we trend that data now, it will give duty holders time

Asia Paci? c to think about planning to do something about it,” he says,

Rig Type Total Rigs Contracted Available Utilization enabling better longer term asset management. “What is

Drillship 14 11 3 78% required now is looking at how equipment is performing over

Jackup 117 108 9 92% time, and what other parameters are changing, such as produc- 38 30 8 78%

Semisub tion ? uid content, to assess how quickly equipment or pipelines

Tenders 24 17 7 70% are potentially degrading, and so when they might fail, and

Total 193 166 27 86% what the best maintenance or inspection regime might therefore

Latin America be, and what action can be taken before it fails.”

Rig Type Total Rigs Contracted Available Utilization

Another example is using data trending to improve structural

Drillship 26 26 0100% management, by helping to understand corrosion and fatigue. “If

Jackup 9 7 2 77% you can lose 50% of your wall thickness through corrosion, and 38 38 0100%

Semisub the structure is corroding 2% per year, you know approximately

Tenders 2 2 0100% how long you have got to use that facility,” Hetherington says. “By

Total 75 73 2 97%

Northwest European Continental Shelf

Rig Type Total Rigs Contracted Available Utilization

Another key factor is reliance on hubs. Since 2000, indirect

Drillship 1 1 0100% hubs and independents (i.e. ? elds that are tied to and rely on

Jackup 49 48 1 97% third party hubs for export), have had consistently lower asset

Semisub 47 43 4 91% production e