Abstract: A wireline or drill pipe retrievable coring tool with an inner barrel to receive a core, a bottom coring tool valve operable to seal off a bottom of the inner barrel and at least one pressure canister operable to receive fluid from the core in the inner barrel. The pressure canister is operable to significantly reduce the pressure inside the inner barrel utilizing an expandable chamber to receive fluid from the core as the tool is removed from the wellbore. In one embodiment, a bottom valve mechanism moves the cored formation materials out of the way of the bottom valve before the bottom valve is closed.

Abstract: A drill string assembly is required that has the capability of operating in well bores that range in hole size from seven to eight inches in diameter. The assembly is used to obtain a large core sample size that is equal to three and one-half inches in diameter and up to ninety feet in length in a single core run. This assembly will be operated with a drill string (i.e. drill pipe) that is capable of being used on standard drilling rigs, which may be used to handle API style drill pipe to conduct coring/drilling operations. The coring tool is comprised of an inner barrel for receiving the core sample.