J-tube Pull-In: Whether to Land on Seabed?

Question:

The question I often received is whether to land the line on the seabed during J-tube pull-in?

Answer:

I have carried out the sensitivity study by performing the static analysis for J-tube pull-in. The results show that:

• If the pipeline is rigid and the clearance between the bell mouth and seabed is small, the most favorable way of J-tube pull-in is to firstly land the rigid riser onto the seabed and followed by J-tube pulling;
• However, if the pipeline is flexible and the clearance between the bell mouth is bigger (e.g. 2 m to 3 m), the most favorable way of J-tube pull-in is to pull the flexible riser directly into the J-tube without touching the seabed.

Notes:

Please note that the answer given above is only based on the sensitivity study I have carried out and may not be applicable to all cases.