The Norne Heidrun pipeline runs 160km from Norne to Heidrun in a flow bundle. Initially, the pig is launched vertically into a 10″ riser, for about 1km. Exit from the riser connector, into 10″ x 16″ expansion section, through a check valve and through and wye piece. In addition there was a 5D bend on the 16″ line. The challenge was to come up with a suitable pig and sealing system to allow dewatering with Glycol on this pipeline.The main challenges were: –
- Overcoming the permanent set in the seals and allowing expansion from 10″ to 16″ with out loss of seal…solution provided by Pipeline Research Limited;
- Correct design of the seal to allow buckling in 10″ and full seal in the 16″…Solution provided by Pipeline Research Limited;
- Negotiating the 16″ wye and the 16″ bends (one demands a long pig, the other a shortened down pig).
Besides providing the basic sealing solution for this pig that fixed the pig body dimensions from an early stage, Pipeline Research Limited are involved in the testing of the pig at Kårstø in Norway. Thanks to the correct seal selection at the outset, this became a matter of optimising from an early stage.