Equal-walled gerotor pump for wellbore applications

A method for pumping and compressing a fluid, the method comprising:

• flowing a fluid through a region between an inner surface of an outer rotor and an outer surface of an inner rotor positioned in the outer rotor,
• wherein the inner rotor comprises an outer surface defining a plurality of teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis,
• wherein the inner surface of the outer rotor is configured to engage with the plurality of teeth and wherein the outer rotor is configured to rotate about a second longitudinal gerotor pump axis,
• wherein the inner rotor and the outer rotor are positioned within a pump housing, wherein an outer surface of the outer rotor defines a plurality of gaps between the pump housing and the outer rotor,
• wherein the fluid in the region is compressed in response to the inner rotor and the outer rotor rotating relative to each other about the first longitudinal gerotor pump axis and the second longitudinal gerotor pump axis, respectively;
• and
• spraying, by a plurality of nozzles, a cooling fluid from the plurality of gaps to the region in which the fluid is being compressed through a wall between the outer surface of the outer rotor and the inner surface of the outer rotor, wherein the cooling fluid reduces a temperature increase resulting from compressing the fluid in the region.

A downhole fluid compression and pumping system comprising:

• a gerotor pump disposed inside a wellbore below a surface, the gerotor pump comprising:
• an inner rotor comprising an outer surface defining a plurality of teeth, the inner rotor configured to rotate about a first longitudinal gerotor pump axis;
• a hollow outer rotor comprising an inner surface configured to engage with the plurality of teeth and to rotate about a second longitudinal gerotor pump axis;
• a pump housing within which the inner rotor and the outer rotor are disposed, wherein an outer surface of the outer rotor defines a plurality of gaps between the pump housing and the outer rotor, wherein the gerotor pump is configured to compress a production fluid produced through the wellbore in a region between the inner surface of the outer rotor and the outer surface of the inner rotor by rotating the outer rotor and the inner rotor relative to each other about the first longitudinal gerotor pump axis and the second longitudinal gerotor pump axis, respectively;
• and
• a plurality of nozzles positioned in the hollow outer rotor, each nozzle having an inlet end in a gap of the plurality of gaps between the pump housing and the outer rotor and an outlet end in the region between the inner surface of the outer rotor and the outer surface of the inner rotor, each nozzle configured to spray cooling fluid from the plurality of gaps into the region between the inner surface of the outer rotor and the outer surface of the inner rotor.