Perforation gun pressure-actuated electrical switches and methods of use

An electrical switch actuated by pressure comprising:

• a housing having a first end and a second end;
• a piston disposed in the housing slidable from a first position to a second position, the piston having a first end and a second end;
• a pressure port extending into the housing from the second end of the housing wherein the pressure port is at least partially exposed to the second end of the piston so as to cause the piston to slide from the first position to the second position upon an application of pressure to the second end of the piston;
• a first pin disposed at least partially in the housing such that the first pin is in electrical contact with the first end of the piston when the piston is in the first position and when the piston is in the second position;
• a second pin disposed at least partially in the housing such that the second pin is in electrical contact with the second end of the piston when the piston is in the first position and not in electrical contact with the piston when the piston is in the second position;
• a third pin disposed at least partially in the housing such that the third pin is in electrical contact with the first end of the piston when the piston is in the second position and not in electrical contact with the piston when the piston is in the first position;
• wherein the piston is electrically conductive so as to allow current to flow from the first pin to the second pin or from the first pin to the third pin;
• and
• wherein the first pin, the second pin, and the third pin are electrically conductive.

A method for arming a charge upon detection of a pressure wave comprising:

• providing a pressure switch comprising a housing, a pressure port extending into the housing, a piston disposed in the housing wherein the piston has a portion of its surface area exposed to the pressure port wherein the piston is configured to slide from a first position to a second position in the housing upon pressure being applied to the piston from the pressure port, a first electrical contact disposed at least partially in the housing such that the first electrical contact is in electrical contact with the piston when the piston is in the first position and when the piston is in the second position, a second electrical contact disposed at least partially in the housing such that the second electrical contact is in electrical contact with the piston when the piston is in the first position and not in electrical contact with the piston when the piston is in the second position, a third electrical contact disposed at least partially in the housing such that the third electrical contact is in electrical contact with the piston when the piston is in the second position and not in electrical contact with the piston when the piston is in the first position wherein the piston is electrically conductive so as to allow current to flow from the first electrical contact to the second electrical contact or from the first electrical contact to the third electrical contact, and wherein the first electrical contact, the second electrical contact, and the third electrical contact are electrically conductive;
• detonating an explosive charge to generate a pressure wave;
• directing said pressure wave through said pressure port;
• and
• utilizing the directed pressure wave to slide the piston from the first position to the second position so as to disengage electrical contact between the first electrical contact and the second electrical contact and to engage electrical contact between the first electrical contact and the third electrical contact.

A switch for controlling detonations in a perforation gun comprising:

• a housing;
• a first non-conductive insert in which a piston cylinder is formed, said cylinder having a first end and a second end;
• a piston slidingly disposed in said piston cylinder and movable from a first position adjacent the first end to a second position adjacent the second end;
• a second non-conductive insert in which a pressure port is defined, said first and second inserts disposed in the housing so that the pressure port is in fluid communication with the piston cylinder;
• a first electrical contact adjacent the piston cylinder;
• a second electrical contact adjacent the first end of the piston cylinder;
• a third electrical contact adjacent the second end of the piston cylinder;
• wherein the piston is electrically conductive so as to allow current to flow from the first contact to the second contact or from the first contact to the third contact.

A perforating gun comprising:

• a first blasting cap;
• a second blasting cap;
• a switch disposed between said blasting caps, said switch comprising:
• a switch housing;
• a first non-conductive insert in which a piston cylinder is formed, said cylinder having a first end and a second end;
• a piston slidingly disposed in said piston cylinder and movable from a first position adjacent the first end to a second position adjacent the second end;
• a second non-conductive insert in which a pressure port is defined, said first and second inserts disposed in the housing so that the pressure port is in fluid communication with the piston cylinder;
• a first electrical contact in electrical contact with the piston;
• a second electrical contact adjacent the first end of the piston cylinder;
• a third electrical contact adjacent the second end of the piston cylinder;
• and
• wherein the piston is electrically conductive so as to allow current to flow from the first contact to the second contact or from the first contact to the third contact.