Marine Drilling Risers

As the search for hydrocarbons extends into ever deeper water and with higher reservoir shut-in pressures the need to extend marine drilling riser performance envelopes is without doubt an enabling factor.  m-pipe® peripheral lines, kill, choke, hydraulic and mud boost,  allows the riser joint weight to be reduced by up to one third and in addition the structural properties of m-pipe® allows efficient load sharing between the peripheral lines and the main pipe. This allows improved structural optimisation of the cross section and allows thinning of the main pipe wall. 

This weight saving allows external buoyancy volumes to be reduced which has cost savings, simplifies handling, reduces deck space storage, reduces drag and simplifies emergency recoil response.These weight savings and structural optimisation are believed to make it possible to extend drilling operations beyond 10,000ft and to shut-in pressures up to 20ksi without modification to the current 4th and 5th generation MODU. In this respect m-pipe is a clear enabler.

m-pipe® auxiliary lines come in discrete lengths up to 80ft, with  4” to 6” internal diameters and are terminated using Magma’s low profile steel connection.

Sizing and pressure rating of peripheral lines

Joint length is assumed to be 75ft-90ft, this is considered to be the current practical length limit for offshore handling.

Laminate design is selected to optimise peripheral line load sharing.  Localloading of riser connectors and main pipe weights are minimised to avoid seal movement.