Scale inhibitor adsorption studies in rock sandstone type

In offshore petroleum fields, the reservoir injection of seawater and produced waters, are in fact common operations with purpose to stimulate and increase the productions. However, this particular method causes the scale formation damaging the production structures. In order to prevent the formation of the aforesaid deposits, it is common to use the squeeze treatment, whereby the scale inhibitors were injected into the wellbore and may also be adsorbed or precipitated into the rock surface. In this study, the interactions between a commercial scale inhibitor and a sandstone rock were evaluated. The column experiments were performed for different feed concentrations and temperatures. The simulation models (Linear Drive Force and General Rate) were used to predict the breakthrough curves and estimate the mass transfer parameters. Whereas, isotherms were obtained from the breakthrough curves and the maximum adsorption capacity of 6.17 mg g⁻¹ was determined. A remarkable agreement between the experimental data and the representation model was observed. The low diffusion coefficients, between 0.1 × 10⁻⁵ and 9.78 × 10⁻⁵ cm² min⁻¹, characterized this particular process as a high diffusion resistance. Regarding the desorption tests, part of the inhibitor still remained in the column. This said behavior in the squeeze treatment is expected, since the inhibitor remains in contact with the rock for a longer period, it being possible to expand the lifetime of the squeeze treatment.