diffusion, dissolution rate.
Diffusion coefficient for the reaction of carbonate rocks dissolution in acid fracturing fluids was measured using rotating disc. Four types of fracturing fluids and two types of carbonate rocks were used. It has been found that for all available speeds of the apparatus, the reaction rate increases with increase of angular rate of the disc, therewith, predominant dissolution of calcite rather than dolomite takes place. It has been demonstrated that at high fracturing pressure, the diffusion is almost insensitive to Neftenol K added to the acid solution, while in the Chevron-Phillips fracturing fluid the diffusion decreases by one-two orders of magnitude, and in acid-oil emulsion fluid it decreases by three orders of magnitude. The measurements’ results were entered into the MFrac acid base.
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