Apparatus and methods of separation of materials in an under-balanced drilling operation

摘要

Disclosed are improved apparatus and methods of separation and control of drilling fluids in under-balanced drilling. Separation is conducted at reduced pressures to improve gas separation efficiencies. Preferably, separation is performed in multiple steps of pressure drops to eliminate foaming and to enhance gas removal. Solids are removed from the shaped bottom of a separation pressure chamber by creating a slurry and fluidizing and agitating the slurry to enhance solids removal.