METHOD AND DEVICE FOR OIL AND GAS WELL DEWAXING Russian patent published in 2006 - IPC E21B37/06 E21B43/24 

FIELD: oil and gas production, particularly to eliminate asphalt-tar-paraffin deposits in oil production equipment.

SUBSTANCE: device comprises heating cable to be lowered in well and heating control system connected to heating cable. The cable has at least two heating members, metal or plastic hollow hydraulic channel arranged along the full length thereof. The cable may have several hydraulic channels of different diameters communicated with metering pump by upper parts thereof and to chemical reagent vessel. Lower channel part is communicated with well fluid. Inner hydraulic channel diameter is 10-50% of cable diameter. Method involves lowering heating cable with heating members in area of possible asphalt-tar-paraffin deposit accumulation; connecting heating cable members with controllable power source; supplying chemical reagent via hydraulic channel in well with the use of metering pump or by chemical reagent gravity due to hydrostatic pressure less than initial asphalt-tar-paraffin crystallization point. The chemical reagents are solvents, inhibitors, demulsifiers or depressants.

EFFECT: reduced power inputs and chemical reagent consumption due combined heat and chemical well treatment.

5 cl, 2 dwg