An arrangement of piping or valves designed to collect or distribute a fluid to or from multiple flow paths, also including points to connect flowlines or umbilicals. Subsea manifolds can be used to gather produced fluids and direct selected wells to a well test line, as well as to distribute injected fluids (gas or water) or gas lift gas to individual wells.


A support structure placed on poorly consolidated, soft or unstable seabed as a footing for structures such as manifolds, jack up rigs etc.


Mud gas separator. A device used to safely vent pockets of free gas from the drilling fluid system, encountered while drilling.


Opening in the hull of a drilling platform, drilling platform or vessel allowing equipment to be past into water in controlled and safe conditions.


Managed Pressure Drilling is an adaptive drilling process used to precisely control the annular pressure profile throughout the wellbore. The objectives are to ascertain the downhole pressure environment limits and to manage the annular hydraulic pressure profile accordingly. It is the intention of MPD to avoid continuous influx of formation fluids to the surface. Any influx incidental to the operation will be safely contained using an appropriate process.

MPD wellbore sealing device

A device which is made up above the BOP which creates a pressure-tight obstruction in the annulus which blocks the further passage of fluid and allows the annulus to be pressurized from the surface while drilling. When an MPD wellbore sealing device is in use, return fluids must exit the annulus through a flow spool or return flow line. ACDs and RCDs are both types of MPD wellbore sealing devices.


Liquid drilling fluid. Drilling mud provides hydrostatic pressure on the borehole wall, lubricates and cools the drill bit and suspends cuttings so they can be carried out.

Mud Weight

The density of the drilling mud, measured in pounds per gallon (lbm/gal) (ppg) or pound cubic feet (pcf).