Direct connect piston-driven bellows pump

A pump for introducing treatment fluid into a well, comprising:

• a power end having a power end housing and a piston disposed in a power end bore;
• a fluid end having a fluid end housing, a fluid end bore, and a chamber in fluid communication with a suction valve and a discharge valve;
• an expandable bellows disposed in the chamber and in fluid communication with the fluid end bore;
• and
• a housing seal disposed between the power end housing and the fluid end housing, wherein the housing seal is configured to seal fluid coupling between the power end bore and the fluid end bore;
• wherein:
• the power end is configured to reciprocally expand and contract the bellows within the chamber based on movement of fluid by the piston, and
• the power end bore and the fluid end bore are fluidly coupled to form a continuous pump bore without external piping therebetween,
• the power end housing and the fluid end housing are configured to be directly coupled together,
• the continuous pump bore is entirely disposed within the power end housing and the fluid end housing,
• the piston further comprises a head and a rod, wherein the rod extends away from the head towards the bellows, the pump further comprising:
• a first seal configured to allow the head to sealingly move within the pump bore;
• a second seal configured to allow the rod to sealingly move within the pump bore;
• and a make-up port in fluid communication with the power end bore or the fluid end bore,
• the make-up port is disposed between the second seal and the bellows,
• the make-up port is disposed in the fluid end and in fluid communication with the fluid end bore, and
• the second seal is disposed in the fluid end bore between the make-up port and the housing seal.

A method of pumping treatment fluid into a well using a bellows pump, comprising:

• providing a power end having a piston with a head and a rod disposed in a power end bore;
• providing a separate fluid end having a fluid end bore and a chamber;
• and
• fluidly coupling the power end bore and the fluid end bore without external piping therebetween, forming a continuous pump bore which consists essentially of the power end bore and the fluid end bore;
• wherein:
• the power end further comprises a power end housing, the fluid end further comprises a fluid end housing, fluidly coupling comprises physically contacting and coupling the power end housing and the fluid end housing, and the continuous pump bore is entirely disposed within the coupled power end housing and fluid end housing;
• further comprising:
• disposing a housing seal between the power end housing and the fluid end housing, which is configured to seal a joint therebetween when the housings are coupled together;
• providing a make-up port in the fluid end;
• providing a second seal in the fluid end bore, wherein the second seal is configured to allow sealing movement of the rod within the fluid end bore, and wherein the make-up port is disposed between the second seal and a bellows of the bellows pump;
• and
• pumping treatment fluid using the bellows pump, wherein the second seal shields the housing seal from high pressure in the bellows during pumping.