Identifying the composition and physical-chemical properties of oil deposits on oil-well tubing surfaces

Abstract

The object of the study is the oil deposits that occur during the operation of oil-producing wells. One of the main elements of oil production is pumping and compressor pipes, through which liquid rises to the surface. During the extraction process, there is a sharp change in thermodynamic conditions (pressure drop, temperature drop), which disrupts the natural phase equilibrium of the raw materials. At the same time, inside the pipes, the components that were in the formation in a dissolved state precipitate out, forming solid deposits characterized by asphalt-resin-paraffin deposits, and complicating the production process. Contrary to conventional wax-dominated precipitation models, findings reveal a distinct resin-asphaltene dominated matrix, characterized by anomalously low paraffin fractions (averaging 1,49%) and elevated silica-gel resins (13,65%). X-ray fluorescence spectroscopy and detailed fractional analysis demonstrate that the structural organization of these deposits is catalytically driven by a pronounced iron dominance (up to 25.5 ppm) synergistically interacting with native sulfur concentrations (1.03–1.74%). Furthermore, localized thermobaric depletion forces suspended chloride microcrystals (peaking at 140,312.04 mg/dm3) to act as inorganic nucleation cores, initiating the agglomeration of high-molecular-weight hydrocarbons and forming intractable water-in-oil emulsions. By quantifying these localized geochemical baselines, this study provides a critical theoretical framework for shifting from generic thermal treatments to targeted, chemically viable remediation strategies utilizing solvent-dispersant packages specifically engineered to passivate reactive iron and dissolve resinous envelopes