Process for the dewaxing of producing formations

A process for the dewaxing of producing formations by means of a water-in-oil nitrogen generating emulsion system, which comprises the steps of:

• a) preparing an aqueous solution of NH.sub.4 Cl having a concentration of from 4.0 to 6.0M;
• b) preparing an aqueous solution of NaNO.sub.2 having a concentration of from 5.0 to 9.0M;
• c) preparing an organic solvent mixture to achieve the hot dissolution of the paraffinic damage;
• d) adding an emulsifier to the organic solvents mixture so that the concentration of emulsifier in the mixture comprises between 0.5 to 2.0%;
• e) adding acetic acid 96% to the NH.sub.4 Cl solution;
• f) adding 50% of the emulsified organic solvents mixture of step d) to the NH.sub.4 Cl and 50% of the mixture to the NaNO.sub.2 solution obtaining thus a NH.sub.4 Cl emulsion and a NaNO.sub.2 emulsion respectively, both emulsions being kept under agitation;
• g) pumping simultaneously into the well the NH.sub.4 Cl and NaNO.sub.2 emulsions, forming a mixture of equimolar NH.sub.4 Cl and NaNO.sub.2 amounts thus initiating an equimolar reaction between the components mixture, this mixture producing nitrogen and heat, while pH is kept between 4.5 and 5.8;
• and
• h) after the pumping of the treating fluid, displacing it from the well by means of an overflush with an aqueous saline fluid.