the open position referring to fig4 a view of valve 20 illustrates the provision 44 that includes a port 52 in operable communication with an optional shifter 50 the shifter 50 is configured to open the port 52 in response to retrieval of the upper completion 16 as illustrated the shifter 50 in this embodiment is a sleeve that is automatically actuated upon retrieval of the upper completion 16 more specifically when upper completion 16 begins to move uphole the provision 44 is shifted to the open position when the provision 44 is in the open position tubular fluid pressure is in communication with the port 52 the port 52 includes an openable member 54 such as a burst disk or similar that when opened provides fluid access to an atmospheric chamber 56 the member 54 opens upon increased tubing pressure and allows fluid to fill the atmospheric chamber 56 fluid in the atmospheric chamber causes one or more pistons 58 to urge the valve 20 to the open position in one embodiment ratcheting devices not shown may be provided in operable communication with the one or more pistons 58 to prevent the pistons from moving in a direction to allow the valve to close by serendipity at some later time it may also be that the valve 20 itself is configured to be locked permanently open by other means if the atmospheric chamber floods the foregoing apparatus and method for its use allows for the retrieval and replacement of an upper completion without the need for a wet connection while one or more embodiments have been shown and described modifications and substitutions may be.