Patent ID: 8789891

Claim:
A method for forming a planar cavern, comprising: drilling a first bore using a first drill string that includes a first drill head, wherein the first bore extends from a first access point through an overburden; extending the first bore through the overburden to a first resource deposit; first sensing a concentration of the first resource at or about a location of the first drill head, wherein the first sensing a concentration of the first resource at or about a location of the first drill head includes: introducing a solvent to the first bore, wherein the solvent is a solvent with respect to at least a first material in the first resource deposit; receiving a return flow of the solvent; determining a concentration of the first material in the return flow by analyzing at least a first sample in the return flow of the solvent; steering the first drill head in response to determining a concentration of the first material in the return flow, wherein a direction of the first bore is altered.