Downhole gas separator and method

摘要

A downhole separator (10) separates gas from well fluids which are pumped intermittently to the surface. The separator includes an outer tubular housing (12) and an inner flow tube (22) for passing well fluids to the surface after separation of the gas from the well fluids. A vortex flow generator or spiral gas separator (20) imparts a helical flow to effect separation of the gas from the well fluids. Gas from the gas chamber flows upward past the vortex flow generator when the pump is not pumping well fluids to the surface.

主权项

1. A downhole separator supported on a tubular string within a borehole for separating gas from well fluids, the well fluids being pumped intermittently to the surface using a cyclic pump, the downhole separator comprising:
an outer tubular housing supported by the tubular and having openings therein to receive well fluids and gas from an annulus radially exterior of the outer tubular housing; an inner flow tube supported within the outer tubular housing by the tubular string and having an open lower end to receive well fluids for upward flow of the well fluids after separation of the gas from the well fluids; and a vortex flow generator disposed radially between the inner flow tube and the outer tubular housing and below the openings in the outer tubular housing to receive a flow of the gas and well fluids from the openings in the outer tubular housing and to impart a helical flow to the gas and well fluids to effect separation of the gas from the well fluids, the gas accumulating in an annular chamber below the vortex flow generator and between the outer tubular housing and the inner flow tube when well fluids are pumped to the surface, the annular chamber having a portion radially interior to the vortex generator; wherein a volume of the gas and well fluids is drawn through the openings in the outer tubular housing, downwardly through the vortex flow generator, and into the annular chamber during an upstroke of a pump cycle in which well fluids are pumped from the inner flow tube to the surface; wherein the helical flow imparted by the vortex generator to the gas and well fluids moving through the vortex generator causes the heavier well fluids to migrate towards an interior wall of the outer tubular housing and displaces the gas radially inwardly in the annular chamber; and wherein the gas displaced radially inwardly in the annular chamber flows upwardly past the vortex flow generator and exits the the downhole separator through the openings in the outer tubular housing during a downstroke of the pump cycle during which the pump does not pump well fluids to the surface.