|Location:||Edvarda, Norwegian Sea, Norway|
|Water Temperature:||No data|
Initial ROV survey: pilot (pre- & post-) and main well (pre-drill) April 2006
|Gas & Oil Company||Statoil|
|Rig operator:||Ocean Rig|
Dr Janne Kaariainen
This Quick Look Report summarises the recent SERPENT work carried out at the Edvarda well in May 2006. The Edvarda well is located 245 km northwest of Kristiansund, in licence block 322 ( Figure 1 ). Edvarda represents the deepest of the five drilling locations included in the 2006 SERPENT programme. Knowledge of these deep sea communities is limited, and so SERPENT research specifically aimed to investigate variation in biological community composition and sedimentary characteristics (accumulation/particle size) both before and after drilling operations. ROV video surveys form a central tool in this investigation process as they help to establish the composition of the megafaunal communities, as well as to identify and map the impact of the drilling operations on the sediment environment.
The ROV onboard Eirik Raude ( Figure 2 ) was used to collect eight straight line video transects (centred on the well head) during each survey (pilot and main well, pre- and post-drilling). Transects length was generally 75m outwards from the well head. This video footage was used to assess and compare changes in the composition of the biological communities and to visually characterise the drilling related impacts on the sediment environment. Additional close up video images of the megafaunal organisms were collected to improve the identification process and to provide some important insights into behavioural patterns.
Attempts were made to assess levels of sediment accumulation using marker buoys labelled at 10 cm intervals ( Figure 3 ). Unfortunately, some marker buoy ropes slipped along the anchor weight, making it difficult to measure the amount of accumulated sediment. Marker buoy design has subsequently been re-evaluated. During the May 2006 SERPENT visit, a total of 17 push-cores were collected ( Figure 4 ): 7 for particle size analysis and 10 for biological analyses. Baited trap experiments ( Figure 5 ) were also set out to assess the composition of the local scavenging community.
Marker buoys used to measure sedimentation rates.
Unfortunately the Edvarda buoys slipped along their anchor weights, making assessment of sediment accumulation impossible.
Sediment push-core operations at Edvarda. Push-core apparatus are attached to the ROV cage.
A baited trap experiment conducted at Edvarda
Some of the organisms observed around the Edvarda drilling site in May 2006 ( Figures 6-8 ).
Finned octopod captured on video at Edvarda on 19 May.
This active octopus was busily making its way up the water column as the ROV tried to keep up with it.
Amphipoda (possibly Amathillopsis sp.) on a crinoid stalk at Edvarda.
Isopoda (possibly Storthyngura sp.) was observed to inhabit number of burrows around the well site. This may represent a new species. Again physical specimens are required for positive identification.
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.
For more information about Janne, please phone the following number.
T: +44 (0)2380 596363