Downhole low-thrust power generation turbine and method for power generation
Aspects presented provide for a low-cost downhole generation turbine. In embodiments, the downhole power generation turbine is configured to minimize the effects of thrust that may be present in the downhole environment, thereby increasing the service life of the downhole power generation turbine. A method of generating an electric current in a downhole turbine generator includes accepting a fluid flow into an inlet of a tubular shape, transmitting the fluid flow through the tubular shape, wherein the fluid flow passes through a fluid flow passage formed by a stator assembly and a rotor assembly, wherein the rotor assembly is configured to spin, wherein the stator and the rotor assemblies are configured such that essentially all thrust loads generated by the fluid flow are transmitted to the stator assembly, actuating an alternator package through connection to the rotor assembly, and producing the electric current through the actuation of the alternator package.
1 . A downhole power generation turbine, comprising:
a tube with an inlet and an outlet, the tube defining an interior space;
a rotor assembly configured within the interior space;
a bearing package connected to the rotor assembly configured within the interior space;
a stator assembly configured around the rotor assembly and within the interior space, wherein the rotor assembly is configured to rotate within the stator assembly, wherein the rotor assembly and the stator assembly form a fluid pathway such that fluid may progress from the inlet to the outlet, and during the progression of the fluid from the inlet to the outlet, mechanical energy of the fluid causes the rotor assembly to rotate, wherein the stator assembly is physically separated from the rotor assembly so a pressure drop that develops from the fluid passing through the rotor assembly and the stator assembly reduces a contribution to an axial thrust force on the bearing package, wherein at least a portion of the fluid is passed along the bearing package, wherein the bearing package comprises a first half of the bearing package that is connected to the rotor assembly distinct from the stator assembly and a second half of the bearing package that is connected to the stator assembly distinct from the rotor assembly, wherein the at least a portion of the fluid lubricates the first half of the bearing package and the second half of the bearing package; and
an alternator package connected to the rotor assembly, the alternator package configured to produce an electrical current.
2 . The downhole power generation turbine according to claim 1 , wherein the rotor assembly and the stator assembly are configured such that no radial gap is present upstream of the stator assembly.
3 . The downhole power generation turbine according to claim 1 , wherein the downhole power generation turbine is configured as a two-stage turbine.
4 . The downhole power generation turbine according to claim 3 , wherein a first stage of the two-stage turbine is an impulse portion and a second stage is a reaction stage.
5 . The downhole power generation turbine according to claim 1 , further comprising an energy storage system connected to the alternator package.
6 . The downhole power generation turbine according to claim 5 , wherein the energy storage system contains at least one battery.
7 . The downhole power generation turbine according to claim 1 , further comprising at least one flow straightener in the downhole power generation turbine.
8 . The downhole power generation turbine according to claim 7 , wherein the at least one flow straightener is at an exit of the downhole power generation turbine.
9 . The downhole power generation turbine according to claim 1 , wherein the stator assembly is configured within the rotor assembly, wherein the rotor assembly rotates around the stator assembly.
10 . A downhole power generation turbine, comprising:
a tube with an inlet and an outlet, the tube defining an interior space;
a rotor assembly configured within the interior space;
a bearing package connected to the rotor assembly configured within the interior space; and
a stator assembly configured around the rotor assembly, the stator assembly configured with a first stage stator and a second stage stator, wherein the first stage stator is configured to accept all pressure drop across the downhole power generation turbine, wherein the rotor assembly and the stator assembly form a fluid pathway, such that fluid may progress from the inlet to the outlet, and during the progression of the fluid from the inlet to the outlet, mechanical energy of the fluid causes the rotor assembly to rotate, wherein at least a portion of the fluid is passed along the bearing package, wherein the stator assembly is physically separated from the rotor assembly, wherein a first half of the bearing package is connected to the rotor assembly distinct from the stator assembly and a second half of the bearing package is connected to the stator assembly distinct from the rotor assembly, wherein the at least a portion of the fluid lubricates the first half of the bearing package and the second half of the bearing package.
11 . The downhole power generation turbine according to claim 10 , wherein the downhole power generation turbine is configured so a pressure drop that develops from the fluid passing through the rotor assembly and the stator assembly reduces a contribution to an axial thrust force on the bearing package.
12 . The downhole power generation turbine according to claim 10 , further comprising an alternator package connected to the rotor assembly, the alternator package configured to produce an electrical current.
13 . The downhole power generation turbine according to claim 12 , further comprising an energy storage system connected to the alternator package.
14 . The downhole power generation turbine according to claim 13 , wherein the energy storage system contains at least one battery.
15 . The downhole power generation turbine according to claim 10 , further comprising at least one flow straightener in the downhole power generation turbine.
16 . The downhole power generation turbine according to claim 15 , wherein the at least one flow straightener is at an exit of the downhole power generation turbine.
17 . The downhole power generation turbine according to claim 10 , wherein the stator assembly is configured within the rotor assembly, wherein the rotor assembly is configured to rotate around the stator assembly.
18 . A method of generating an electric current in a downhole turbine generator, comprising:
accepting a fluid flow into an inlet of a tubular shape;
transmitting the fluid flow through the tubular shape, wherein the fluid flow passes through a fluid flow passage formed by a stator assembly and a rotor assembly, wherein the rotor assembly is configured to spin, wherein the stator assembly and the rotor assembly are configured such that essentially all thrust loads generated by the fluid flow are transmitted to the stator assembly, wherein at least a portion of the fluid flow is passed along a bearing package comprising a first half of the bearing package connected to the rotor assembly distinct from the stator assembly and a second half of the bearing package connected to the stator assembly distinct from the rotor assembly, wherein the at least a portion of the fluid flow lubricates the first half of the bearing package and the second half of the bearing package;
actuating an alternator package through connection to the rotor assembly; and
producing the electric current through the actuation of the alternator package.
19 . The method according to claim 18 , further comprising charging at least one battery from the produced electric current.
20 . The method according to claim 18 , wherein the downhole turbine generator is configured as a two-stage turbine generator.