Downhole shunt tube isolation valve system

A downhole shunt tube isolation system, comprising:

• a first slurry tube segment;
• a second slurry tube segment;
• a valve housing, the valve housing including an in-line valve connected to the first slurry tube segment and the second slurry tube segment, the in-line valve configured to establish a substantially straight gravel slurry pathway through the first slurry tube segment and the second slurry tube segment when the valve is in an open position and to block flow of the gravel slurry from the first tube segment to the second tube segment when the valve is in a closed position;
• and
• a valve actuation housing having a piston hydraulic chamber, a central bore extending axially through the valve actuation housing, and a fluid channel extending from the central bore to the piston hydraulic chamber, wherein the piston hydraulic chamber operates with respect to a pressure differential to cause a valve actuator to move the valve from the open to the closed position;
• wherein the fluid channel includes a plug disposed within the fluid channel to seal the piston hydraulic chamber from the central bore, wherein sealing the fluid channel hydraulically locks the valve in the open position, and
• an actuation mechanism connected to the fluid channel, the actuation mechanism configured to open the fluid channel to hydraulically unlock the valve, wherein opening the fluid channel generates a pressure differential that causes a valve linkage connected between the valve actuator and the in-line valve to transition the valve from the open to the closed position,
• wherein the valve linkage converts linear motion by the valve actuator into a motion that closes the in-line valve.

A method for actuating a downhole shunt tube isolation system, comprising:

• sealing a piston hydraulic chamber disposed within a valve actuator housing, via a plug, to hydraulically lock an in-line valve in an open position;
• connecting a first tube segment through the in-line valve to a second tube segment, the in-line valve configured to convey a gravel slurry in a substantially straight gravel slurry pathway from the first tube segment through the in-line valve to the second tube segment when the in-line valve is in the open position;
• displacing a portion of the plug to open a fluid path through the plug to the piston hydraulic chamber, wherein opening the fluid path to the piston hydraulic chamber hydraulically unlocks the in-line valve;
• and
• placing the in-line valve into a closed position via biasing force to block the flow of the gravel slurry from the first tube segment to the second tube segment, wherein the biasing force is generated by a pressure differential across the piston with the fluid path opened,
• wherein placing the in-line valve into a closed position includes converting linear motion by the piston into a motion that closes the in-line valve.