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DECOMMISSIONING INSIGHT
2015
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7.1.3 Rig Type
There are a number of methods that can be used for platform well P&A and the rig type will depend on whether
the original drilling derrick is in place and the water depth where the platform is located.
Platform wells are typically plugged and abandoned in phases. The first phase can be rig-less and uses lower cost
methods such as wireline, coil tubing or a hydraulic workover unit. This is followed by the second and third phases
that are more likely to require a rig.
In the CNS and NNS/WofS areas, the majority of platform wells (70 per cent) will be plugged and abandoned using
an integral platform rig. By contrast, jack-up rigs are most commonly used (93 per cent) in the SNS and Irish Sea as
many of the platforms do not have integral rigs.
For subsea wells, the deeper water depths in the CNS and NNS/WofS mean that semi-submersible rigs are typically
used, while jack-up rigs will be used in the shallower waters of the SNS and Irish Sea.
Figure 11: Forecast Rig Type for Well Plugging and Abandonment from 2015 to 2024
Platform Well P&A
Subsea Well P&A
70%
7%
4%
17%
2%
Integral Rig
Jack-Up Rig
Semi-Submersible Rig
Rig-Less Intervention
Not Yet Known
93%
1%
4%
2%
Integral Rig
Jack-Up Rig
Semi-Submersible Rig
Rig-Less Intervention
Not Yet Known
83%
5%
12%
Jack-Up Rig
Semi-Submersible Rig
Rig-Less Intervention
Not Yet Known
91%
2%
7%
Jack-Up Rig
Semi-Submersible Rig
Rig-Less Intervention
Not Yet Known
Source:Oil &GasUK
91%
2%
7%
Jack-Up Rig
Semi-Submersible Rig
Rig-Less Intervention
Not Yet Known
Source:Oil &GasUK
CNS and NNS/WofS
SNS and Irish Sea
CNS and NNS/WofS
SNS and Irish Sea