Combination packer/safety valve assembly for gas storage wells

Combination packer/safety valve assembly to control upward flow of a pressurised well fluid through a casing string of a subterranean well has a body lowerable into the casing string which has (a) a normally closed first integral passage through which, when opened, pressurised well fluid may internally traverse the body portion; and (b) a second internal passage for receiving a pressurised control fluid from a source thereof; the combination packer and safety valve having (c) first means carried by the body and operative to open the normally closed first passage during the presence of a predetermined first control fluid pressure within the second internal passage; and (d) second means carried by the body and operative to anchor and seal the body within the casing string in response to a predetermined second control fluid pressure created within the second internal passage and greater than the predetermined first control fluid pressure USE/ADVANTAGE : Combination packer and safety valve assembly. The assembly is used for shuttering in a gas storage well without mechanical action of tools to open the flow valve, set the assembly in the casing, or subsequently release it from the casing, which uses control fluid pressure of different magnitudes.