METHOD FOR PROCESSING BOTTOMHOLE FORMATION ZONE Russian patent published in 2018 - IPC E21B33/138 E21B43/22 E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to the oil industry and can be used in the completion of wells to increase the productivity of a formation, folded with carbonate reservoirs with hard-to-recover oil reserves. Method of treating the bottomhole formation zone includes primary opening of a well, perforation of the bottomhole zone of the productive formation. In the bottomhole zone of the productive formation, an acid-decomposable protective shield is created by pumping said acid-decomposable solution at a pressure, which is 10–15 % higher than the design cementing pressure. Casing is run, annular space is cemented, perforation of the bottomhole zone of the productive formation is repeated through the casing installed in the well and the breakdown of the acid-decomposable protective screen is performed by acidizing the bottomhole zone of the productive formation. Primary opening is carried out with an active emulsion composition. Perforation is carried out under a layer of active emulsion. Lower level of active emulsion layer should be at least 25 m, and the upper level should not exceed 150 m from the perforation interval. Active emulsion composition used is a composition with the following ratio of components, wt%: MIA-prom grade K – 5.0–43.0; sodium nitrite – 4.0–26.0; urea – 5.0–37.0; water – balance.

EFFECT: technical result is an increase in processing efficiency due to a complex effect on the bottomhole formation zone, combining primary and secondary opening into a single process, resulting in increased productivity of the well.

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