Acid treatment (AT) is one of the most effective and cost-cutting methods for the near-wellbore zone (NWZ) treatment to increase oil production. The issue of conducting AT is particularly pressing in fields with hard-to-recover reserves of the Tyumen suite. Due to the naturally low permeability of the reservoir, there is a decrease in the injectivity of injection wells, leading to failure to achieve design values, a decrease in the flow rate of liquid and formation pressure, precipitation of asphaltenes, and clogging of the NWZ. In current regulatory and technical documents, the volume of acid composition is recommended to be 0,5 – 1,5 m3 per 1 m of perforated thickness. However, this proposed approach for calculating the volume of acid compositions does not take into account the filtration and capacity properties of the reservoit, the type of injected water, the presence of hydraulic fracturing, the temperature of the NWZ, and the frequency of treatment. Additional attention should to be paid to calculating the volume of acid for production and injection wells, as they are characterized by different types of contamination and depths of penetration. To eliminate uncertainty, it is proposed to create a methodology for calculating the volume of injected acid compositions. The authors propose a formula for calculating the volume of acid during AT for injection and production wells. The technological and economic efficiency of applying this methodology has been assessed on the injection well stock.
References
1. Panikarovskiy V.V., Panikarovskiy E.V., Metody sokhraneniya i vosstanovleniya fil’tratsionnykh kharakteristik slozhnopostroennykh kollektorov (Methods for maintaining and restoring the filtration characteristics of complex reservoirs), Moscow: Publ. of Gazprom ekspo, 2010, 104 p.
2. Novikov V.A., Derendyaev R.A., Abashev D.A., Kuznetsov D.S., Study of the influence of the number of acid treatments on their efficiency based on geological field analysis (In Russ.), Tekhnologii nefti i gaza, 2022, no. 3, pp. 45–49, DOI: https://doi.org/10.32935/1815-2600-2022-140-3-45-49
