Unplugging brine-submerged perforations

Claim 1

A well treating process, for bringing heat and oil solvent into contact with plugged fluid passageways which extend between the borehole and reservoir and are covered by a column of relatively dense brine, comprising: compounding a self-reactive heating solution which (a) consists essentially of an aqueous liquid solution of nitrogen-generating reactants arranged for yielding heat and gas at a significant but moderate rate at the reservoir temperature and (b) contains enough total dissolved solids to provide a solution density exceeding that of the brine in the borehole; flowing at least one slug each of said heating solution and a liquid oil solvent which becomes a hot liquid solvent for petroleum type compounds at the temperature yielded by the heating solution into the well at a flow rate and sequence such that (a) a significant portion of the heating solution sinks into the column of brine in the borehole and reacts to yield heat and gas that contact the plugged fluid passageways and (b) a significant portion of the oil solvent is heated by the reaction and is displaced into contact with the plugged passageways; and removing the resulting solution or dispersion of plugging materials in aqueous or oleaginous liquid by producing fluid from the well.