The inventive technology, in particular embodiments thereof, may be described as an apparatus (e.g., a pump) that imparts work to and redirects a fluid, and that features an impeller configured to contact and redirect an impeller inflow along a toroidal flowpath to generate an impeller discharge that has both axial and tangential velocity components, where the axial velocity component is substantially 180 degrees relative to a direction of an impeller inflow, in a meridional plane, the apparatus also featuring a diffuser having a diffuser axis that is aligned with an impeller axis of rotation, the diffuser featuring a diffuser outlet annular radial size that is greater than a diffuser inlet annular radial size; and/or curved diffuser vanes established as part of the diffuser, that redirect the impeller discharge so as to reduce the tangential velocity components.

The inventive technology, in particular embodiments thereof, may be described as an apparatus (e.g., a pump) that imparts work to and redirects a fluid, and that features an impeller configured to contact and redirect an impeller inflow along a toroidal flowpath to generate an impeller discharge that has both axial and tangential velocity components, where the axial velocity component is substantially 180 degrees relative to a direction of an impeller inflow, in a meridional plane, the apparatus also featuring a diffuser having a diffuser axis that is aligned with an impeller axis of rotation, the diffuser featuring a diffuser outlet annular radial size that is greater than a diffuser inlet annular radial size; and/or curved diffuser vanes established as part of the diffuser, that redirect the impeller discharge so as to reduce the tangential velocity components.

A mud turbine apparatus includes a rotor including an inner ring configured to be positioned around a drill pipe, an outer ring that is positioned around and spaced apart from the inner ring, a plurality of magnets coupled to the outer ring, and a plurality of blades coupled to and extending between the inner ring and the outer ring. The apparatus also includes a stator including a housing configured to fit into an annulus between the drill pipe and a surrounding tubular, and to receive the outer ring at least partially therein, and a plurality of coils that communicate with the magnets, such that in a first mode of operation, the rotor rotates to assist fluid flow therethrough and decrease drilling fluid pressure in the annulus, and in a second mode of operation, the rotation of the rotor impedes fluid flow therethrough and increases drilling fluid pressure in the annulus.

A mud turbine apparatus includes a rotor including an inner ring configured to be positioned around a drill pipe, an outer ring that is positioned around and spaced apart from the inner ring, a plurality of magnets coupled to the outer ring, and a plurality of blades coupled to and extending between the inner ring and the outer ring. The apparatus also includes a stator including a housing configured to fit into an annulus between the drill pipe and a surrounding tubular, and to receive the outer ring at least partially therein, and a plurality of coils that communicate with the magnets, such that in a first mode of operation, the rotor rotates to assist fluid flow therethrough and decrease drilling fluid pressure in the annulus, and in a second mode of operation, the rotation of the rotor impedes fluid flow therethrough and increases drilling fluid pressure in the annulus.

A plurality of energy-generator pods, and methods of use, are provided along a rotatable tubular string extending downhole from surface into a wellbore. In embodiments, rotation of the tubular acts as a rotor of the pod and an outer component about the tubular, capable of relative rotation thereabout, forms the stator. The pod can also be equipped with bi-directional wireless electronic data communication including communication uphole to surface from sensors downhole, pod-to-pod, and down-hole communication to downhole tools. Pods can be fit to centralizers already employed for rotary tubular strings, the centralizer portion engaging the wellbore and remaining stationary relative to the rotating centralized tubular.

A plurality of energy-generator pods, and methods of use, are provided along a rotatable tubular string extending downhole from surface into a wellbore. In embodiments, rotation of the tubular acts as a rotor of the pod and an outer component about the tubular, capable of relative rotation thereabout, forms the stator. The pod can also be equipped with bi-directional wireless electronic data communication including communication uphole to surface from sensors downhole, pod-to-pod, and down-hole communication to downhole tools. Pods can be fit to centralizers already employed for rotary tubular strings, the centralizer portion engaging the wellbore and remaining stationary relative to the rotating centralized tubular.

An equivalent circulating density (ECD) reduction tool can include a positive displacement fluid motor, and a fluid pump configured to be driven by the fluid motor. The fluid pump can include a fluid inlet and a fluid outlet disposed on respective opposite sides of an external flow restriction. A method of controlling equivalent circulating density (ECD) in a well can include connecting an ECD reduction tool in a tubular string, deploying the tubular string with the ECD reduction tool into the well, thereby forming an annulus between the tubular string and a well surface surrounding the tubular string, and flowing a fluid into the well through the tubular string, the fluid returning from the well via the annulus. The flowing step can include operating a positive displacement fluid motor of the ECD reduction tool, the fluid motor thereby rotating an impeller shaft of a fluid pump.

Provided is a wellbore tractor and method for operating a well system. The wellbore tractor, in one aspect, includes a base member, and one or more turbines fixed to the base member for rotating the base member in a first rotational direction based upon a first direction of fluid flow. The wellbore tractor, according to this aspect, further includes one or more wellbore engaging devices radially extending from the base member, the one or more wellbore engaging devices contactable with a surface of a wellbore for displacing the base member and one or more turbines axially downhole as the one or more turbines rotate in the first rotational direction.

Provided is a wellbore tractor and method for operating a well system. The wellbore tractor, in one aspect, includes a base member, a hydraulically powered drive section coupled to the base member, and one or more turbines coupled to the hydraulically powered drive section for powering the hydraulically powered drive section based upon fluid flow across the one or more turbines. The wellbore tractor, according to this aspect, further includes one or more wellbore engaging devices radially extending from the hydraulically powered drive section, the one or more wellbore engaging devices contactable with a surface of a wellbore for displacing the wellbore tractor axially downhole.

Provided is a wellbore tractor and method for operating a well system. The wellbore tractor, in one aspect, includes a base member, a hydraulically powered drive section coupled to the base member, and one or more turbines coupled to the hydraulically powered drive section for powering the hydraulically powered drive section based upon fluid flow across the one or more turbines. The wellbore tractor, according to this aspect, further includes one or more wellbore engaging devices radially extending from the hydraulically powered drive section, the one or more wellbore engaging devices contactable with a surface of a wellbore for displacing the wellbore tractor axially downhole.