METHOD FOR TREATMENT OF BOTTOMHOLE FORMATION ZONE Russian patent published in 2024 - IPC E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: proposed invention relates to oil and gas industry, namely to acid treatment of formation with subsequent neutralization of acid residues after treatment. Proposed method comprises pumping acid composition, buffer and alkali fringe into reservoir. Acid composition is selected based on the results of filtration tests in laboratory conditions based on the maximum dissolution efficiency of the collector, the reaction time in the aqueous medium and the amount of unreacted acid composition, acid composition is pumped into the well in a volume that provides the required coverage of the formation, completely squeezing into the formation with process fluid, which is used as process or mineralized water. At the final stages of pumping, a buffer in the form of a liquid with neutral pH and an alkali fringe in form of 20% aqueous solution of NaOH is injected successively in a volume ratio of 1:2 for neutralization of at least 90% of unreacted acid composition in formation to ensure pH 7±0.3 in produced product from formation after injection.

EFFECT: reduced time for acid treatment of the formation and time for neutralization with increased efficiency of treatment of the bottomhole formation zone.

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