Project Profile
Location: Thames Complex, southern North Sea, UK
Field type: Gas condensate
Water Depth: 32 to 37 metres
Production start-up: 1990
The Welland Gas Field is situated about 20Km Southeast of the Thames Complex in the Southern sector of the North Sea. The field contains the blocks 53/4a, 49/28a and 49/29b. In 1989 the UK Government approved the project development plan. The development was a 2 well unmanned processing platform with 3 subsea wells tied back. Three subsea tie-back wells are located in Blocks 53/4, 49/29 and 49/28. Water depths within the Welland field range from 32-37 metres. Seabed sediments are predominately comprised of sand and slightly gravelly sand. The development utilised a small unmanned steel platform and gas produced from the field is transported to the Bacton Gas Plant. The field commenced the production in 1990. J P Kenny was selected to provide the detailed design, engineering and procurement support for the export pipeline, flowline and umbilical system. In 2010 the field approved decommissioning programme.
**Welland field: Perenco estimate of decommissioning costs: pipeline and umbilical infrastructure £5.76m., Platform and jacket preparation and removal: £10.92m., two platform and three subsea well abandonments: £13.94m., subsea wellhead protection structure removal: £2.7m., Total: £33.2m.** DF 04/01/2018
Operators:
Perenco UK: Operator with 100% interest
Contractors:
J P Kenny: Detailed design, engineering and procurement support
Northern Offshore UK: Drilling contract
PanGeo Subsea: Survey for Perenco UK Limited for their Welland Gas field Decommissioning Programme. The workscope of the contract includes carrying out both SBI and multi-beam surveys on the Welland platform and three remote wellheads to locate, size and verify the depth of burial of concrete mattresses laid decades ago to protect pipeline and umbilicals. PanGeo verified depth of burial of the concrete mattresses to a resolution of 5cm.