COMPARATIVE ANALYSIS OF SCALE INHIBITORS FOR EQUIPMENT PROTECTION IN BASHKORTOSTAN FORMATION WATER CONDITIONS

The article presents a comparative analysis of the effectiveness of scale inhibitors – aminotris(methylenephosphonic acid) (ATMP), hydroxyethylidene diphosphonic acid (HEDP), and polyacrylic acid (PAA) – in preventing calcium carbonate and sulfate deposits in model formation water representative of Bashkortostan oilfields. The formation water, characterized by high mineralization (50–200 g/L) and containing Ca²⁺, HCO₃⁻, SO₄²⁻, and Cl⁻ ions, promotes the formation of dense deposits that reduce equipment throughput and cause corrosion. A laboratory experiment was conducted at inhibitor concentrations of 10 and 50 mg/L using steel coupons placed in model water replicating the composition of regional formation waters. The experiment involved dynamic conditions with stirring at 70 °C, simulating real oil production environments. The results showed that HEDP exhibited the highest efficiency (86.0–86.9 % for coupons), followed by ATMP (82.2–83.2 %), while PAA demonstrated lower efficiency (76.6–77.6 %) due to its limited chelating ability in highly mineralized environments. For in-depth analysis, the data were processed using a neural network (multilayer perceptron), which performed interpolation and extrapolation of inhibition efficiency for concentrations of 20, 30, 40, 60, and 70 mg/L. The predictions confirmed the superiority of phosphonates, with HEDP reaching 88.2 % efficiency at 70 mg/L, and indicated a slowdown in efficiency gains at higher dosages. Visual inspection of the coupons revealed minimal corrosion and loose deposit structures in the presence of inhibitors, highlighting their protective effect on equipment. The findings suggest that HEDP and ATMP at concentrations of 30–50 mg/L are advisable for optimizing oil production processes in Bashkortostan, providing effective scale inhibition at economically viable dosages. Future research prospects include exploring combined inhibitors and nanotechnology to enhance efficiency in challenging conditions.