Selection of a base for an intensifying composition for treating geothermal wells to remove silica deposits

UDK: 549.514.5

DOI: 10.24887/0028-2448-2026-7-125-129

Key words: geothermal energy, scale dissolution, amorphous silica, silicon dioxide, ICP-OES, WDXRF

Authors: S.V. Aksenova (Gubkin University, RF, Moscow; ZN STC LLC, RF, Moscow); S.I. Kudryashov1,3 (Gubkin University, RF, Moscow; Zarubezhneft JSC, RF, Moscow); M.M. Mukhin. (Gubkin University, RF, Moscow); A.M. Kozlov (Gubkin University, RF, Moscow); Ya.O. Simakov (ZN STC LLC, RF, Moscow); S.V. Aksenov (Gubkin University, RF, Moscow)

In the modern world, the demand for environmentally friendly energy sources is growing every day. Geothermal energy is an eco-friendly, renewable energy source not depending on weather conditions. Geothermal energy resources are highly varied and complex in nature and almost each of them has its own unique characteristics that must be taken into account for the effective use in heat recovery and electricity generation. When thermobaric conditions to which the fluid is subjected change along its entire path, the problem of the formation of poorly water-soluble deposits often arises, the most «problematic» of which are calcite, silica, iron oxides, and sulfates. The key factors influencing the formation of deposits are changes in temperature, pH, and liquid composition. The aim of this study is to select a base for a composition capable of dissolving deposits that predominantly consist of amorphous silica. The dissolving capacity of sodium carbonate Na2CO3, sodium hydroxide NaOH, and hydrofluoric acid HF was determined; deposit samples from the Mutnovskoye field (Kamchatka peninsula) were used as the soluble deposits. The solubility of the deposits was determined by the gravimetric method at various temperatures and solvent concentrations. The residual silicon concentration in the solution was determined by inductively coupled plasma optical emission spectroscopy (ICP-OES). The performed work shows the influence of temperature and solvent concentration on the quality of dissolution of amorphous silica deposits. The possibility of using various compositions as a base for treating geothermal wells from deposits is demonstrated.

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