No connection proven between formation of the pit and well at Snorre B
The Snorre B platform in the North Sea. (Photo: Harald Pettersen)
On Thursday, an injection test was performed in the well that is tied in to the subsea template. The test confirmed that there is no communication between the well and the pit.
Analysis of sediment samples also revealed no sign of hydrocarbon content. No movement has been observed since Monday in the pit near the subsea template. The subsea template is still being monitored continuously with a remotely operated underwater vehicle.
Since it is not confirmed a connection between formation of the pit and the well, other explanations are being examined. None of these are considered to be a serious factor as regards the technical integrity of the subsea template or the wells.
Production from the template will remain shut in until further examinations have been concluded. The other production from Snorre B has now resumed.
Previous update (20 May)
Production from Snorre B template shut down
Production from a subsea template at the Snorre B platform was shut down on 17 May following the discovery of an abnormal erosion of mass under the template.
Over the last 24 hours, no movement has been observed in the pit at the subsea template. The area is under continuous ROV surveillance and sediment samples have been taken. "Brine" (water with heavier sediments) was pumped into the well for a brief period in the event that there was some sort of connection between the pit and the well. There have been no signs of hydrocarbon leaks in any of the surveys carried out since the pit was discovered on 17 May.
"The pit is stable and is being monitored continuously. The most important thing for us now is to clarify what caused the pit to form, and a number of explanations are being examined," says Bente Aleksandersen, Statoil's senior vice president for Operations South.
On Monday, 33 people were moved over to the Safe Scandinavia, and then transported onshore as a precautionary measure after movement and hydrocarbon indications were observed in the pit. In connection with this, the emergency response organisation was mobilised, and then demobilised the same evening. The Petroleum Safety Authority Norway is being provided with continuous updates.
Statoil has decided to keep production shut down until the necessary investigations have been carried out.