Patent ID: 7445429

Claim:
An apparatus for pumping a well fluid containing gaseous and liquid components, comprising: a central rotary pump section for pumping the liquid components; an annular turbine section having a plurality of turbine stages surrounding the central rotary pump section for compressing the gaseous components, each of the turbine stages comprising a plurality of rotatable turbine blades and a turbine diffuser, the turbine blades being rotatable relative to the turbine diffuser; wherein the central rotary pump section comprises a plurality of pump stages, each pump stage comprising an impeller and a pump diffuser, the impeller of each pump stage being rotatable relative to the pump diffuser of each pump stage; a housing containing the turbine section and the central rotary pump section; a separating device in the housing upstream of the turbine section and the central rotary pump section for separating well fluid flowing into the housing into an outer portion and an inner portion, the outer portion containing more liquid components than the inner portion, and the inner portion containing more gaseous components than outer portion; and a cross-over device downstream of the separating device and upstream of the turbine section and the central rotary pump section for guiding the outer portion of the well fluid into the central rotary pump section and guiding the inner portion of the well fluid into the annular turbine section.