Meny
The Troll field test, together with the test performed in Trondheimsfjord (2003), is a part of a Technology Qualification Plan (TQP) model testing (small prototype) scale 1:3.
Two anchors of scale 1:3 were used in this testing program (12 in all). Both anchors have instrumentation: one has its instrumentation installed on the inside of the anchor while the other has external containers where the instrumentation is mounted. Each anchor has 500m of 38mm wire laid out on the seabed for later loading and retrieval.
A total of 12 anchor drop tests have been performed from different heights ranging from 15m to 75m over the seabed at the Troll Field Area 2 approximately 3.8 kilometers West of the Troll A platform. These tests comprised the following:
• 10 vertical pullout tests directly after anchor installation at t = 0 i.e. where no consolidation had taken place,
• 1 inclined load test six months after anchor installation,
• 1 vertical pullout test four months after installation and when primary consolidation was assumed complete.
While the observation from this test has shown excellent results in term of marine operation procedure, hydrodynamic behavior during drop, penetration into the seabed, and pull out capacity; probably the most important finding from the 1:3 scale tests was that the hydrodynamic stability was verified. In Trondheimsfjord the current can be extreme in relation to normal sea tidal currents. Therefore, due to the current, the anchor starts off with a rotation but quickly recovers due to the hydrodynamic design. The final anchor tilt is approximately one degree.
