The owner or operator of any well or wells which produce oil or gas from any stratum below the lowest potable water aquifer shall be permitted to allow such wells to remain open for the purpose of introducing air, gas, water, or other liquid pressure into said oil or gas bearing stratum for the purpose of recovering the oil and gas contained therein, provided that the introduction of such pressure of air, gas, water, or other liquid into said stratum shall be through casing or tubing which shall be so anchored and packed that no other oil, gas or water bearing stratum above or below said stratum shall be affected by the introduction of such pressure.
58 P.S. § 7