Micro-controller-based switch assembly for wellbore systems and method
A method for firing a detonator in a chain of switch assemblies includes a step of lowering the chain of switch assemblies into a wellbore; a step of powering-up a switch assembly of the chain of switch assemblies; a step of independently entering through a set of states during which the switch assembly interacts with a downstream switch assembly and determines a status of one or more elements associated with the switch assembly; and a step of firing a detonator electrically connected to the switch assembly or entering a sleeping state.
1. A switch assembly, which is part of a chain of switch assemblies, the switch assembly comprising:
a power supply;
a micro-controller P B that has no address;
a thru-line switch including a first semiconductor element; and
a detonator switch including a second semiconductor element,
wherein the micro-controller P B is configured to directly communicate with an upstream or downstream switch assembly through a pulsing scheme, and
wherein the micro-controller P B receives no command from a surface controller.
2. The switch assembly of claim 1 , further comprising:
a transmit module connected to the micro-controller and configured to send voltage pulses along a voltage line; and
a receive module connected to the micro-controller and configured to receive a voltage pulse along the voltage line.
3. The switch assembly of claim 1 , wherein the micro-controller is configured to independently enter through a set of states during which the switch assembly interacts with the downstream switch assembly.
4. The switch assembly of claim 3 , wherein the micro-controller is configured to determines a status of one or more elements associated with the switch assembly.
5. The switch assembly of claim 1 , wherein the micro-controller enters through six different states during operation.
6. The switch assembly of claim 1 , wherein the micro-controller is configured to determine whether a detonator is connected to the switch assembly.
7. The switch assembly of claim 6 , wherein the micro-controller is configured to send a short pulse to the upstream switch assembly to inform the upstream switch assembly that the detonator is attached to the switch assembly.
8. The switch assembly of claim 7 , wherein the micro-controller is configured to determine whether a thru-line that connects the switch assembly to the downstream switch assembly is shorted.
9. The switch assembly of claim 8 , wherein the micro-controller is configured to determine, when the thru-line is shorted, that the switch assembly is the most distal switch assembly from a surface of the earth.
10. The switch assembly of claim 9 , wherein the micro-controller is configured to start a timer.
11. The switch assembly of claim 10 , wherein the micro-controller is configured to close the detonator switch when a line voltage is larger than a firing voltage, and when within a time counted by the timer, to fire the detonator.
12. The switch assembly of claim 8 , wherein the micro-controller is configured to close the thru-line switch when the thru-line is not shorted, to allow communication between the micro-controller and the downstream switch assembly.
13. The switch assembly of claim 12 , wherein the micro-controller is configured to determine whether a pulse from the downstream switch assembly is received, send two long pulses separated by a given time to the surface controller when the pulse from the downstream switch assembly is received, and enter a sleeping state.
14. The switch assembly of claim 1 , wherein the thru-line switch is connected to a setting tool.