Select fire switch control system and method
A select fire system and method for controlling operations in a gun string assembly includes perforating guns and switch subs mechanically connected in the gun string assembly. Each of the switch subs includes a switching element, input links and output links. The switch subs and perforating guns communicate with each other through the input and output links. The switching elements keep track of the state of the sub and switches states based on trigger conditions such as environment conditions, perforating gun conditions, or input conditions from surface.
1. A select fire system for controlling operations in a gun string assembly, the select fire system comprising:
a plurality of perforating guns; and
a plurality of switch subs mechanically connected in the gun string assembly, each of the plurality of switch subs comprising:
(a) a switching element comprising environmental sensing ports configured to sense at least one of well conditions, perforating gun conditions, and input conditions from surface;
(b) a plurality of input links configured for operative electrical connections to at least one of the plurality of perforating guns; and
(c) a plurality of output links configured for operative electrical connections to at least another one of the plurality of perforating guns.
2. The select fire system claim 1 wherein each of the plurality of switch subs are configured to electronically communicate with at least one or more other switch subs of the plurality of switch subs through at least one of the plurality of input links.
3. The select fire system claim 1 wherein each of the plurality of switch subs are configured to electronically communicate with at least one or more other switch subs of the plurality of switch subs through at least one of the plurality of output links.
4. The select fire system claim 1 wherein each of the plurality of switch subs are configured to electronically communicate with a wellhead through at least one of said plurality of input links or through at least one of the plurality of output links.
5. The select fire system of claim 1 wherein the switching element further comprise one or more pressure switches configured to sense pressure in a downstream gun.
6. The select fire system of claim 1 wherein the switching element is configured with a timer configured to track elapsed time between events in each of the plurality of switch subs.
7. The select fire system of claim 1 wherein the switching element is configured with a memory configured to store a state of the plurality of switch subs.
8. The select fire system of claim 1 wherein the environmental sensing ports are configured with a plurality of pressure switches; the plurality of pressure switches are configured to sense pressure of a downhole perforating gun.
9. The select fire system of claim 8 wherein a binary logic output of each of the plurality of pressure switches is input to a logic controller.
10. The select fire system of claim 9 wherein the logic output from the logic controller determines a state of each of the plurality of switch subs.
11. The select fire system of claim 1 , further comprising:
a self-detection failure feature, operating in conjunction with the select fire system, for controlling perforation operation of each of the plurality of switch subs in the gun string assembly by detecting a failure condition in a switch sub of the plurality of switch subs, disarming an appropriate perforating gun of the gun string, and bypassing to an upstream switch sub of the plurality of switch subs.
12. The select fire system of claim 11 wherein the self-detection failure feature includes an operator alert configured to alert an operator when the failure condition is detected.