Lithological displacement of an evaporite mineral stratum

In an underground formation containing an evaporite mineral stratum comprising a mineral selected from the group consisting of trona, nahcolite, wegscheiderite, shortite, northupite, pirssonite, dawsonite, sylvite, carnalite, halite, and combinations thereof, said mineral stratum lying immediately above a non-evaporite stratum of a different composition, said formation comprising a defined weak parting interface between the two strata and above which is defined an overburden up to the ground surface,

• a method for solution mining of said evaporite stratum, comprising a lithological displacement of the evaporite mineral stratum, wherein a fluid is injected at the parting interface to lift the evaporite stratum at a lifting hydraulic pressure greater than the overburden pressure, thereby forming a gap at the interface and creating a mineral free-surface, said lifting hydraulic pressure applied being characterized by a fracture gradient between 0.9 psi/ft (20.4 kPa/m) and 1.5 psi/ft (34 kPa/m);
• wherein the fluid is injected in a directionally drilled well which is cemented and cased;
• wherein said directionally drilled well comprises at least one horizontal borehole section comprising an in situ injection zone being in fluid communication with the strata interface;
• and
• wherein the fluid injected through the well exits through the in situ injection zone of the horizontal borehole section, thereby lifting the overlying evaporite stratum at the interface so that the gap created at the interface is an extension of the horizontal borehole section.