Abstract: The separator includes a vertical cylindrical pressure vessel having elliptical top and bottom heads. A mechanical device, referred to as a vortex tube cluster of vertical tubes, is mounted in the upper section of the vessel chamber, spaced above the bottom head to define a lower chamber section for fluid and solids separation. Pressurized drilling fluid returns are directed tangentially into the vortex tubes and a subsequent centrifugal action is generated. Contained gas separates and forms a gas vortex which exits upwardly from the vortex tubes and vessel top. The liquids and solids discharge into the vessel lower chamber section where solids settle by gravity to the bottom. The solids are withdrawn from the base of the vessel by a slurry pump. The oil and water components of the fluid layer also separate by gravity and are individually removed from the vessel.

Abstract: The drilling fluid returns from underbalanced drilling are introduced into a separator and a separate gas stream is recovered. The gas stream is cleaned at the well site to remove entrained liquid and particulate solids, to produce gas suitable to be fed to a compressor. The cleaned gas is compressed to re-injection pressure and recycled to the well.

Abstract: The separator comprises an elongated, cylindrical, horizontal pressure vessel. An involute feed inlet introduces the drilling fluid into the top of the vessel chamber at its first end. The feed inlet is designed to reduce the flow velocity of the incoming feed stream and introduce it horizontally toward the first end head of the vessel. A weir, slanted away from the first end head, extends upwardly from a point close to the head's base. The curved head, vessel side wall and slanted weir form an inlet compartment of hopper-like configuration designed to funnel settling cuttings to a bottom outlet for removal with an auger pump. This design enables the cuttings to be removed while drilling progresses, without the build up of cuttings piles. The vessel also has a second weir at about its midpoint, for trapping fine solids in a second compartment. Riser outlets are provided in the second compartment for water removal and in the third compartment for oil removal. Gas is removed through an overhead outlet.