METHOD OF WELL DEWAXING Russian patent published in 1997 - IPC

FIELD: oil producing industry, in particular, methods of control of resin-paraffin accumulations in recovery of paraffin oil; applicable in well dewaxing. SUBSTANCE: method includes heating of zone of paraffin accumulations up to temperature exceeding the melting point of paraffin. Elevated temperature is attained by successive pumping through well space of portions of aqueous solutions of diethylamine and hydrochloric acid in volume ratio of 1: 2 and total volume of two successive portions equalling the half of space through which agents are supplied. Portions of aqueous solutions of diethylamine and hydrochloric acid are injected through annular space. In case of bridging of tubing with paraffin plug, run into tubing are flushing pipes down to bridging paraffin plug. Injected in succession through pipes are aqueous solutions of diethylamine and hydrochloric acid with simultaneous additional lowering of flushing pipes. This operation is continued up to full removal of bridging paraffin plug from tubing. Concentration of diethylamine and hydrochloric acid in aqueous solutions is taken in stoichiometric ratio. EFFECT: higher efficiency of control of paraffin accumulations, reduced labor input and extended technological capabilities of the offered method. 4 cl, 2 tbl