There are four pipeline installation methods:
1. S-Lay: fast, S-Lay vessel, 10-30 inches diameter, 50-5000 m deep
2. J-Lay: slow, J-Lay vessel, 10-30 inches diameter, 50-5000 m deep
3. Reel-Lay: very fast, Reel-Lay vessel, up to 12 inches, up to
4. Pipeline to

 

Summary
There are four main methods for pipeline installation:

S-Lay: fast, S-Lay vessel, 10-30 inches diameter, 50-5000 m deep
J-Lay: slow, J-Lay vessel, 10-30 inches diameter, 50-5000 m deep
Reel-Lay: very fast, Reel-Lay vessel, up to 12 inches, up to
Pipeline tow:

S-Lay
The S-Lay method is used for pipelines with diameters from 10 to 30'' in water up to 5000 m. For this type of installation requires an S-Lay vessel, which is basically a floating welding factory, where pieces of 12 m long pipes joint to form the pipeline and lowered to the seabed (Fig. 1). The pipeline from the vessel to the seabed takes an S-shape that why we call the method S-Lay
J-Lay
The J-Lay method is used for pipelines with diameter from 10-50'' in deep and ultra deep waters. A vessel with a vertical J-lay tower is required. Pieces of pipe are welded together in the tower and lowered vertically in to the seabed (Fig. 2)

Reel-Lay

Pipeline tow