Effect of Chemical Solvents on the Removal of Halite Scales from Porous Media
S.A. Hosseini, Y. Salimidelshad, M.R. Esfahani, H. Aloki Bakhtiari and H. Karimaie
Event name: 81st EAGE Conference and Exhibition 2019
Session: Poster: Interpretation Development & Case Studies
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 413.94Kb )
Price: € 20
Halite scales have been considered as fluid flow barrier in near-wellbore that lead to productivity reduction by impairing the permeability. To evaluate reservoirs, core analysis is vital for quantitative measurement of the reservoir rock properties. One of the main goals is to remove all the fluids such as salts. In this study, five calcite core plugs were saturated with 200,000 ppm of halides, then their removal is investigated using different solvents including methanol, ethanol, tetrahydrofuran, chloroform, and dichloromethane. Then, experiments such as permeability measurement, Zeta potential, AAS, and microscopic analysis were performed, and these tests indicate the cleaning ability of each solvent on each sample. The results showed that methanol could restore the permeability to 64% after saturating core with salt, followed by the highest removal of sodium and potassium ions by Atomic Absorption Spectrometry (AAS) analysis. Moreover, results of zeta potential revealed that ethanol makes the system more water-wet than other solvents. Microscope image analysis demonstrated that dichloromethane altered the morphology of salt in terms of size and shape, while other solvents such as methanol and ethanol made the crystals agglomerated. Consequently, the results illustrate that methanol has better efficiency for the elimination of salts from porous media.