WELL BOTTOMHOLE ZONE TREATMENT METHOD FOR WASHING PARAFFIN ASPHALT AND TERRY MATTERS Russian patent published in 2018 - IPC E21B37/06 E21B43/22 C09K8/524 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry, in particular to methods for treating the bottomhole zone of a production well or a well that has been transferred to an injection well from a production well, whose work is complicated by the precipitation of paraffinic asphalt and terry matters (ATM) in the bottomhole zone. A method for treating the bottomhole zone of a borehole for the removal of paraffinic asphalt pitch substances involves pumping a composition of 5.0–30.0 wt% cosolvent with surfactant – SAS and 70.0–95.0 wt%, technological aging. At the same time, in the composition, the bottoms of butyl alcohols or a solvent of a paraffin oil or an oil solvent are used as a cosolvent, as a SAS, a complex SAS or a polyether with a low pour point is used, and an industrial solvent is used as the solvent. Amount of surfactants in the cosolvent is 0.05–0.2 wt%. And for wells with an acceleration from 0 to 1 m³/h injection of the composition is carried out with a constant operation of the hydraulic generator.

EFFECT: technical result is an increase in the efficiency of cleaning the pore space of the bottomhole zone of the well from paraffin ATM by increasing the solvent and dispersing capacity of the composition with respect to paraffinic ATM, increase in well productivity due to complete dissolution and removal of paraffin ATM from the bottomhole zone of the well and expansion of the technological capability of the process through the use of reagents with the involvement of petrochemical waste.

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