|Water Temperature:||0 - 3° C|
|Dates:|| 10 – 13 July 2006
7 - 14 August 2006
30 August – 04 September 2006
11 – 17 October 2006
|Gas & Oil Company||Statoil|
|Rig operator:||Stena Drilling|
|SERPENT Representatives:||Dr Janne Kaariainen and Dr Daniel Jones|
This Quick Look Report summarises the recent SERPENT work carried out at the Brugdan well between July and October 2006. It is a sub-basaltic well located in licence block 006 off the Faroe Islands ( Figure 1 ). The well has been drilled to approximately 3780m below sea level. Data have been collected at four time points during the exploration of Brugdan, allowing sedimentary and faunal changes with time since drilling to be monitored. Specifically, SERPENT research attempted to examine the differences between benthic communities under different sedimentary regimes, and to investigate sediment changes due to drilling activity.
The work was carried out from the exploration rig Stena Don (operated by Stena Drilling). This rig had access to two Remotely Operated Vehicles (ROVs): a work class magnum 070 and a Sea Owl 590 Observation class ROV.
The colour video camera fitted to both ROVs enabled high-quality footage of the seafloor to be obtained. In total, 24 straight line vide transects (centred of the well head) were collected during surveys of the Brugdan prospect (4 pre-drilling transects, 8 during surveys 2 and 3, and 4 transects during survey 4). Transects extended up to 200m from the well centre. This video footage was used to assess and compare changes in the composition of the biological communities in relation to drilling disturbance. Additional video footage was collected to accurately characterise the visual drilling related impacts on the sediment environment.
ROV operated push cores were used to collect sediment samples during al the visits. These included samples for particle size distribution and chemical analyses during all the surveys as well as replicate meiofaunal samples collected along a transect from three different locations during visit 3. Additionally, Ekman grab was trialled during visit 2 but the sediment environment was found to be unsuitable for this sampler type at the Brugdan location. Vertical sediment accumulation around the survey area was investigated by placing marker buoys (labelled at ten centimetre intervals) in strategic positions around the well head ( Figure 4 ).
Specimens of benthic organisms were collected by utilising both the ROV suction sampler and setting bottle-type baited amphipod traps on the seabed.
Some of the organisms observed around the Brugdan drilling site in August and October 2006 .
A sea spider (pycnogonid).
Benthic fish at Brugdan
A typical benthic assemblage at Brugdan; (left to right) an anemone with a sea spider.
Sea spider (Pycnogonid) with tubular sponge, on rock.
Pink asteroid starfish
(left) gastropod mollusc with small mussel (probably fallen from the rig); (right) tube anemone (top) and gastropod mollusc.
For further information please contact:
Dr Andrew Gates , SERPENT Project, National Oceanography Centre, Southampton, UK.
or Dr Daniel Jones , SERPENT Project, National Oceanography Centre, Southampton, UK