## 2 Materials and Methods
As a result, a large-volume hydrochloric acid treatment (LHAT) is recommended for the best results. In a work ([PERSON] et al., 2019 [22]), it is reported that the volume of acid composition per 1 m of treatment interval varies in the range from 3 to 5 m\({}^{3}\) when the LHAT technology is applied for carbonate deposits. The perforated formation thickness in this target well reaches 8 m, therefore, it is necessary to inject acid in the volume of 40 m\({}^{3}\) to maximize the BHZ permeability. When all of obtained values are substituted in Equation (10), the calculated predicted decrease of the skin factor is 4.0, which has a significant impact on changes in the amount of fluid recovered from this well. The conducted calculation of the predicted value of the skin factor after acid treatment of the target facility under study, which equals \(S=1.1-4.0=-2.9\), allows to perform the comparative analysis between the actual values of the well oil and fluid flow rate obtained over 6 months and those predicted using hydrodynamic simulation, as given in Table 4. Figure 6 illustrates the hydrodynamic model. Figure 5: Image of diffusing particles under microscope. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Speed**} & \multicolumn{4}{c}{**Plunger Diameter, mm**} \\ \cline{2-5}  & \multicolumn{2}{c}{**100**} & \multicolumn{2}{c}{**120**} \\ \cline{2-5}  & **Pumping Rate, L/s** & **Pressure, MPa** & **Pumping Rate, L/s** & **Pressure, MPa** \\ \hline II & 2.24 & 50.0 & 3.23 & 34.4 \\ III & 4.28 & 25.9 & 6.16 & 18.0 \\ IV & 6.50 & 17.1 & 9.36 & 11.8 \\ V & 9.78 & 11.3 & 14.08 & 1.9 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Pumping rate and pressure developed by AzINMASH-30 unit. According to Table 4, the predicted oil and liquid flow rates almost fully correspond to their actual values, since the average deviations were 5.33% and 5.12%, respectively, while the standard deviations were 0.67 and 0.74 with variation coefficients of 12.58% and 14.47%, respectively. Therefore, it is possible to note high accuracy of predicting the flow rates according to the developed technique, which will allow evaluating effectiveness of acid treatment of productive deposits that are lithologically represented by carbonate varieties. At further calculations using the hydrodynamic model, it is possible to analyse incremental recovery of hydrocarbons for several years to come, i.e., to make a conclusion on the success of the oil recovery stimulation method. Below is the analysis of the effectiveness of the designed procedure at the target facility in comparison with the basic variant using hydrodynamic simulation; its results are given in Table 5. The calculation was conducted through 2029. Analysing the data presented in Tables 4 and 5, we can conclude that following the acid treatment of the target oil producing well, a significant growth in oil production is expected, namely, a fourfold increase. Based on the conducted forecast, by the beginning of 2029 at the target oil producing well, the cumulative oil production will increase by 9.88 thousand m\({}^{3}\), and the cumulative liquid production will increase by 50.25 thousand m\({}^{3}\), following the performed HAT job. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Date**} & **Oil Flow Rate, m\({}^{3}\)/day** & **Deviations in Oil** & **Liquid Flow Rate, m\({}^{3}\)/day** & **Deviations in** \\ \cline{2-7}  & **Actual** & **Design** & **Flow Rate, \%** & **Actual** & **Design** & **Liquid Flow Rate, \%** \\ \hline June 2019 & 1.7236 & 1.7236 & - & 3.2110 & 3.2110 & - \\ July 2019 & 7.4143 & 7.0612 & 4.76 & 20.9546 & 19.9949 & 4.58 \\ August 2019 & 7.2705 & 6.9148 & 4.89 & 20.9147 & 19.8235 & 5.22 \\ September 2019 & 7.2128 & 6.7741 & 6.08 & 20.8075 & 19.6605 & 5.51 \\ October 2019 & 6.9606 & 6.6387 & 4.63 & 20.5710 & 19.5057 & 5.18 \\ November. 2019 & 6.9340 & 6.5086 & 6.14 & 20.6366 & 19.3587 & 6.19 \\ December. 2019 & 6.7527 & 6.3835 & 5.47 & 20.0301 & 19.2191 & 4.05 \\ \hline \hline \end{tabular}
\end{table}