Pressure activated completion tools and methods of use

A downhole tool for use in a tubing string, the downhole tool comprising:

• (i) a tubular body configured to be in fluid communication with the tubing string having an upstream and a downstream, the tubular body having at least one burst port configured to receive a burst plug wherein the burst plug is configured to burst at a threshold pressure;
• (ii) a movable inner sleeve within the tubular body that can slide inside of the tubular body from a first position to a second position when exposed to hydraulic pressure;
• and
• (iii) a fluid compartment positioned between the movable inner sleeve and the tubular body, the fluid compartment configured to receive a compartment fluid and operable for fluid communication of the compartment fluid from inside the fluid compartment to outside the burst port, the communication of the compartment fluid to outside the burst port being prevented by the burst plug when disposed in the burst port and the compartment fluid being able to pass to outside the burst port when the burst plug is not disposed in the burst port,
• wherein in operation:
• the burst plug that is disposed within the at least one burst port bursts in response to hydraulic pressure equal to or greater than the threshold pressure that is transferred from the pressurized fluid communicated down the tubing string to the movable inner sleeve through the compartment fluid that is received by the fluid compartment to the burst plug;
• and
• upon bursting of the burst plug, the compartment fluid passes to outside the burst port and the movable inner sleeve slides from the first position to the second position such that the downhole tool is activated.