Controlling a fluid well

Abstract

In apparatus for controlling a fluid production well, a control device D, such as a choke, located downhole is operable selectively by first and second drive means ( 2,3 ). First and second power supply means and first and second control channels (ChA, ChB) for control signals are provided for the first and second drive means, the arrangement being such that if one of the power supplies fails, the respective drive means is operable via the other power supply. First and second means (DEM 1 A, DEM 1 B) for routing control signals from the first and second channels respectively to the first and second drive means are provided, the routing means being interconnected so that, in the event of a fault, control signals from the second channel are routed via the first routing means to the second drive means and/or control signals from the first channel are routed via the second routing means to the first drive means.

1 . Apparatus for controlling a fluid well comprising, a control device for location downhole and operable selectively by first and second drive means, there being first and second power supply means and first and second control channels for control signals for the first and second drive means, the arrangement being such that if one of the power supplies fails, the respective drive means is operable via the other power supply, the apparatus further comprising first and second means for routing control signals from the first and second channels respectively to the first and second drive means, the routing means being cross-connected so that, in the event of a fault, control signals from the second channel are routed via the first routing means to the second drive means and/or control signals from the first channel are routed via the second routing means to the first drive means.  
   
   
       2 . Apparatus for controlling a fluid well, comprising: 
 a) a control device for location downhole;    b) first drive means for operating the control device;    c) second drive means for operating the control device, the control device being operable selectively by the first and second drive means;    d) first power supply means;    e) second power supply means;    f) a first control channel, for control signals for the first drive means;    g) a second control channel, for control signals for the second drive means;    h) first switching means, for switching power and control signals to the first drive means; and    i) second switching means, for switching power and control signals to the second drive means; wherein 
 i) the first and second power supply means and the first and second control channels are connected to the first switching means and also to the second switching means, the arrangement being such that, in normal operation, power from the first power supply means powers the first drive means via the first switching means and power from the second power supply means powers the second drive means via the second switching means, and in the event of a fault, power from the first power supply means powers the second drive means or power from the second power supply means powers the first drive means; and  
 ii) the first switching means includes means for routing control signals from the first control channel to control the first drive means and the second switching means includes means for routing control signals from the second control channel to control the second drive means, the first and second routing means being cross-connected so that, in the event of a fault, control signals from the second channel are routed via the first routing means to the second drive means and/or control signals from the first channel are routed via the second routing means to the first drive means.  
   
   
   
       3 . Apparatus according to  claim 2 , wherein, in normal operation, power from the first power supply means is provided to the first switching means from the second switching means and power from the second power supply means is provided to the second switching means from the first switching means.