Systems and methods for activating a pressure-sensitive downhole tool

A system for conveying and activating a downhole tool within a wellbore via a tubing string, wherein the system comprises:

• a coupling configured for connection between the tubing string and the downhole tool, wherein the coupling comprises:
• an internal cavity configured to fluidly connect with and receive internal pressure from an internal fluid passage of the tubing string when the coupling is connected with tubing string;
• a first fluid passage extending between the internal cavity and the wellbore on an exterior of the coupling thereby fluidly connecting the internal cavity with the wellbore when the downhole tool is conveyed within the wellbore;
• a stopper and stopper seat disposed along the first fluid passage, wherein the stopper seat is offset from a central axis of the coupling, wherein the stopper seat is configured to hold the stopper, and wherein the stopper is configured to be passed through the internal fluid passage of the tubing string and be seated in the stopper seat to block the first fluid passage to thereby fluidly disconnect the internal cavity from the wellbore;
• a second fluid passage extending between the internal cavity and the wellbore on the exterior of the coupling thereby fluidly connecting the internal cavity with the wellbore;
• a fluid blocking member disposed along the second fluid passage, wherein the fluid blocking member blocks the second fluid passage;
• and
• a third fluid passage fluidly connected with the internal cavity;
• and
• an activator connected to the coupling, wherein:
• the third fluid passage fluidly connects the internal cavity with the activator;
• the third fluid passage is configured to communicate the internal pressure from the internal cavity to the activator;
• and
• the activator is configured to activate the downhole tool when the internal pressure reaches a predetermined pressure.

A method comprising:

• connecting a coupling between a downhole tool and a lower end of a tubing string such that an internal cavity of the coupling is fluidly connected with an internal fluid passage of the tubing string and a pressure passage of the coupling is fluidly connected with the downhole tool, wherein the internal cavity and the pressure passage are fluidly connected;
• lowering the downhole tool within the wellbore via the tubing string thereby causing a fluid to flow from the wellbore into the tubing string via a first fluid passage of the coupling, wherein the first fluid passage extends between the internal cavity and an exterior of the coupling;
• blocking the first fluid passage to fluidly disconnect the internal cavity from the wellbore;
• pressurizing the fluid within the internal fluid passage of the tubing string to increase pressure within the internal cavity to:
• a first pressure to cause operation of the downhole tool;
• and then
• a second pressure to cause operation of a fluid blocking member, wherein the second pressure is higher than the first pressure, wherein the fluid blocking member is disposed along a second fluid passage extending between the internal cavity and the exterior of the coupling, wherein the fluid blocking member blocks the second fluid passage, and wherein the operation of the fluid blocking member comprises unblocking the second fluid passage to fluidly connect the internal cavity with the wellbore;
• and
• raising the downhole tool within the wellbore via the tubing string thereby causing the fluid to flow out of the tubing string into the wellbore via the second fluid passage.