Patent ID: 6973936
Filing Date: 2005-12-13
Classification: E21B,G01F,Y10T

Abstract:
1. A fluid injection system for controlling the distribution of fluid from a supply line to a selected well at an adjustable rate, comprising: a metering body having a bore for containing fluid; a fluid barrier segregating the bore into variable-volume first and second chambers, the fluid barrier movable in response to a pressure difference between the first and second chambers; a first input-output port for passing fluid into and out of the first chamber, and a second input-output port for passing fluid into and out of the second chamber; a multi-position valve comprising a first position for passing fluid from the supply line into the first chamber, thereby moving the fluid barrier to displace fluid from the second chamber back through the valve to an injection point, and a second position for passing fluid from the supply line to the second chamber, thereby moving the fluid barrier to displace fluid from the first chamber back through the valve to the injection point, the valve further comprising a variable valve opening for controlling flow between the supply line and the metering body; a position sensor for sensing position of the fluid barrier within the metering body; and a control system in communication with the position sensor and including a timer for timing displacement of the fluid barrier to selected positions, the control system for selectively adjusting the variable valve opening in response to displacement time of the fluid barrier and for selectively reversing the position of the multi-position valve in response to position of the fluid barrier.