14. Mud / cuttings separator
This unit works on the principal of a screw press whereby cuttings and associated mud are transported via an auger type screw through a cylindrical wedge wire screen fitted with an adjustable pressure plate at the discharge port. The action of the screw pushing cuttings against the pressure plate generates a squeezing effect forcing the associated mud through the screen. This mud is collected and returned to the active system, whilst processed cuttings exit the periphery of the compressed pressure plate.
Suppliers claim the unit will reduce oil on cuttings (OOC) to approximately 5 - 6% which may equate to a compaction ratio of 30 - 40%, although this will depend on the type of cuttings material and the quality of the primary shakers. The unit has the advantage of being synthetic mudall (1.7m × 0.5m × 0.5m) and is simple in operation with low maintenance. A dedicated operator is required initially but the responsibility for unit maintenance should go to the Drilling Contractor.
The unit was developed in Norway where a number of systems are in use and is now marketed in the UK by two companies, Sea Force Engineering and Apollo Services UK Ltd.