Pressure intensifier for hydraulically setting a downhole tool

A well system, comprising:

• a wellbore located in a subterranean formation;
• and
• a downhole tool positioned in the wellbore, the downhole tool including:
• a mandrel;
• a pressure intensifier positioned radially about the mandrel the pressure intensifier including:
• a first piston having a first pressure receiving end with a piston surface area (A1) and a first pressure output end with a piston surface area (A2), where A1 is greater than A2;
• a second piston having a second pressure receiving end with a piston surface area (A3), where A3 is greater than A2;
• a piston cylinder radially encompassing the first and second pistons, wherein the piston cylinder includes a first piston cylinder section sized for the first pressure receiving end of the first piston, a second piston cylinder section sized for the first pressure output end of the first piston and a third piston cylinder section contiguous with the second piston cylinder section, the third piston cylinder section sized for the second pressure receiving end of the second piston;
• a fluid chamber defined between the first pressure output end of the first piston, the second pressure receiving end of the second piston, and the piston cylinder, the fluid chamber fluidly coupling the first pressure output end of the first piston to the second pressure receiving end of the second piston;
• and
• a pressure relief system, wherein the pressure relief system evacuates fluid from the fluid chamber when pressure in the fluid chamber rises above a pressure relief system threshold.

A method, comprising:

• selecting a first pressure P1 for a downhole tool positioned in a wellbore, the downhole tool including:
• a mandrel;
• and
• a modular pressure intensifier positioned radially about the mandrel the pressure intensifier including:
• a modular first piston having a first pressure receiving end with a piston surface area (A1) and a first pressure output end with a piston surface area (A2), where A1 is greater than A2;
• a second piston having a second pressure receiving end with a piston surface area (A3), where A3 is greater than A2;
• a modular piston cylinder radially encompassing the first and second pistons, wherein the modular piston cylinder includes a first piston cylinder section sized for the first pressure receiving end of the first piston, a second piston cylinder section sized for the first pressure output end of the first piston and a third piston cylinder section contiguous with the second piston cylinder section, the third piston cylinder section sized for the second pressure receiving end of the second piston;
• a fluid chamber defined between the first pressure output end of the first piston, the second pressure receiving end of the second piston, and the piston cylinder, the fluid chamber fluidly coupling the first pressure output end of the first piston to the second pressure receiving end of the second piston;
• and
• a pressure relief system, wherein the pressure relief system evacuates fluid from the fluid chamber when pressure in the fluid chamber rises above a pressure relief system threshold,
• selecting a second pressure P2, wherein P2 is not equal to P1;
• and
• replacing the first piston with a replacement piston and the second piston cylinder section with a replacement piston cylinder section sized for the pressure output end of the replacement piston, the replacement piston for generating the second pressure P2, wherein the replacement piston has a pressure receiving end with a piston surface area (A4) and a pressure output end with a piston surface area (A5), where a ratio of A4 to A5 is not equal to a ratio of A1 to A2.