Safety switch for well tools
AssigneeOtis Engineering Corporation
InventorsJames B. Adams, Jr., Thomas M. Deaton
Life of this patent
Estimating the term…
Abstract
A mechanical safety switch for closing electrical contacts in a well tool. The mechanical switch has several safety requirements which must be satisfied before the electrical contacts will close including upward pull on a wireline and a preselected value of fluid pressure exterior to the switch. The safety switch can be incorporated into a well perforating gun to provide safe, reliable operation of an electrically powered perforating gun by a conventional wireline. Preferably, the electrical circuits of the well perforating gun should include a motion sensor and a timer for increased safety.
Claims26
A switch for activating electrical circuits in a well tool, comprising:
- a. a housing;
- b. means for attaching one end of the housing to a wireline;
- c. a piston slidably disposed within the housing;
- d. a first electrical contact comprising a pin projecting from one end of the piston;
- e. the piston having a first position in which it is held from sliding relative to the housing with the pin spaced longitudinally from a second electrical contact in the switch and a second position in which the pin can engage the second electrical contact;
- f. means for holding the piston in its first position;
- and
- g. means for releasing the piston from the holding means.
A mechanical switch for activating electrical circuits in a well tool suspended from a wireline within a well flow conductor, comprising:
- a. a housing;
- b. means for attaching one end of the housing to the wireline;
- c. a piston slidably disposed within the housing;
- d. a first electrical contact comprising a pin projecting from one end of the piston;
- e. the piston having a first position in which the piston is held from sliding relative to the housing and the pin is spaced longitudinally from a second electrical contact in the switch and a second position in which the pin can engage the second electrical contact;
- f. means for holding the piston in its first position;
- g. means for releasing the piston from the holding means by upward pull on the wireline.
A well perforating gun assembly having a carrier for a detonator and explosive charges, an electrical power supply contained within the gun assembly, and a mechanical switch for activating electrical circuits within the gun assembly to connect the power supply to the detonator comprising:
- a. a housing containing the mechanical switch and the electrical power supply;
- b. means for attaching one end of the housing to a wireline;
- c. a piston slidably disposed within the housing;
- d. a first electrical contact comprising a pin projecting from one end of the piston;
- e. the piston having a first position in which the piston is held for sliding relative to the housing and the pin is spaced longitudinally from a second electrical contact in the gun assembly and a second position in which the pin can engage the second electrical contact;
- f. means for holding the piston in its first position;
- and
- g. means for releasing the piston from the holding means by upward pull on the wireline.
Dependencies are inferred from the claim text.