Closed loop multiphase underbalanced drilling process

摘要

The present invention provides apparatus and methods for handling fluids returning from a well. The fluids are introduced into a separator and a separated gas stream is recovered or recycled. The gas stream may comprise more than one phase. The separated gas stream is urged through a multiphase pump before it is recovered. Alternatively, the return fluids may pass through a multiphase pump before it is introduced into the separator.