| 20100208408 | Light-Activated Switch and Circuit for Select-Fire Perforating Guns - Apparatus and method are provided for selectively firing apparatus in a well when the apparatus is fired by an electrical voltage and produces light upon firing. A photoresistor or other device changes in an electrical property when the light from firing of a section of the apparatus impinges on the photoresistor or other electronic device. The change in electrical property shifts the state of a relay such that the following section of the device can be fired with a voltage of the opposite polarity to that used in firing the preceding section. A test and resetting apparatus for the select-fire apparatus is also provided. | 08-19-2010 |