CPC E21B 34/08 (2013.01) [E21B 23/0413 (2020.05); E21B 23/042 (2020.05); E21B 34/14 (2013.01)] | 22 Claims |
1. A downhole tool activation device, comprising:
a valve disposed between a pressurized fluid and an activation port,
a counter device connected to the valve, wherein the valve is configured to open when the counter device has moved an activation distance in an activation direction,
a piston engaged with the counter device, having a wellbore pressure from a fluid source applied to a first side, and a pressure in a fluid reservoir applied to the second side, the piston configured to move a step distance in a first direction when the wellbore pressure exceeds the pressure in the fluid reservoir, and configured to move a step distance in an opposite direction driven solely by a greater pressure in the fluid reservoir than the wellbore pressure, and
a flow restrictor in fluid communication with the fluid reservoir and fluid source, configured to restrict the flow of fluid between the fluid source to the fluid reservoir,
wherein the fluid source is a second fluid reservoir separated from the wellbore fluid by a barrier configured to allow pressures applied to the wellbore fluid to be transmitted by the barrier to the second fluid reservoir.
|