Nested bellows pump and hybrid downhole pumping system employing same

A system for removing wellbore liquids from a wellbore, the wellbore traversing a subterranean formation and having a tubular that extends within at least a portion of the wellbore, the system comprising:

• a nested bellows fluid end pump comprising a housing having a first end and a second end, the housing having a cylindrical body, the cylindrical body having an inner wall;
• a traveling bulkhead, the traveling bulkhead sealingly positionable along the inner wall of the cylindrical body;
• a first inner bellows having a first end and a second end, the first end of the first inner bellows connected to the first end of the housing, and the second end of the first inner bellows is connected to the first end of the traveling bulkhead;
• a second inner bellows having a first end and a second end, the first end of the second inner bellows connected to the second end of the traveling bulkhead, and the second end of the second inner bellows is connected to the second end of the housing;
• a first outer bellows having a first end and a second end, the first end of the first outer bellows connected to the first end of the housing, and the second end of the first outer bellows is connected to the first end of the traveling bulkhead;
• a second outer bellows having a first end and a second end, the first end of the second outer bellows connected to the second end of the traveling bulkhead, and the second end of the second outer bellows is connected to the second end of the housing;
• wherein a first inner chamber is defined by the first inner bellows, a second inner chamber is defined by the second inner bellows, a first outer chamber is defined by an annulus formed by the first outer bellows and the first inner bellows, and a second outer chamber is defined by the second outer bellows and the second inner bellows;
• a closed loop hydraulic system in fluid communication with the first inner chamber and the second inner chamber of the nested bellows fluid end pump;
• and
• a power end pump for pressurizing the first inner chamber or the second inner chamber of the nested bellows fluid end pump;
• wherein the power end pump and the nested bellows fluid end pump form a pump assembly.

A method of removing wellbore liquid from a wellbore, the wellbore traversing a subterranean formation and having a tubular that extends within at least a portion of the wellbore, the method comprising:

• powering a downhole power end pump, the downhole power end pump in fluid communication with a closed loop hydraulic system;
• and
• driving a nested bellows fluid end pump, the nested bellows fluid end pump in fluid communication with the closed loop hydraulic system and comprising a housing having a first end and a second end, the housing having a cylindrical body, the cylindrical body having an inner wall;
• a traveling bulkhead, the traveling bulkhead sealingly positionable along the inner wall of the cylindrical body;
• a first inner bellows having a first end and a second end, the first end of the first inner bellows connected to the first end of the housing, and the second end of the first inner bellows is connected to the first end of the traveling bulkhead;
• a second inner bellows having a first end and a second end, the first end of the second inner bellows connected to the second end of the traveling bulkhead, and the second end of the second inner bellows is connected to the second end of the housing;
• a first outer bellows having a first end and a second end, the first end of the first outer bellows connected to the first end of the housing, and the second end of the first outer bellows is connected to the first end of the traveling bulkhead;
• a second outer bellows having a first end and a second end, the first end of the second outer bellows connected to the second end of the traveling bulkhead, and the second end of the second outer bellows is connected to the second end of the housing;
• wherein a first inner chamber is defined by the first inner bellows, a second inner chamber is defined by the second inner bellows, a first outer chamber is defined by an annulus formed by the first outer bellows and the first inner bellows, and a second outer chamber is defined by the second outer bellows and the second inner bellows;
• pumping the wellbore liquid from the wellbore with the nested bellows fluid end pump,
• wherein the pumping step includes:
• (i) pressurizing the wellbore liquid with the nested bellows fluid end pump to generate a pressurized wellbore liquid at a discharge pressure;
• and
• (ii) flowing the pressurized wellbore liquid at least a threshold vertical distance to a surface region.