UNDER-BALANCED DRILLING SEPARATION APPARATUS AND METHODS

摘要

Disclosed are inventions to improved apparatus and methods of separation and control of drilling fluids in under-balanced drilling. The separated returning stream materials are measured and used to control the additive gas mixing process to maintain under-balanced drilling conditions. 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.