Experimental study of the microscopic fractal characteristics of limestone etched by acid

For an acid fracturing treatment, the conductivity of fractures strongly depends on both macroscopic reaction rate and microscopic etched characteristics of fracture walls. A series of experiments of reaction between acid and limestone have been done using orthogonal arrays. Acid concentration, reaction temperature, reaction time and acid type were taken into account. The influences of these factors on the macroscopic reaction rates and microscopic fractal features of the etched samples have been discussed. The relationship between macroscopic reaction rates and microscopic fractal characteristics of etched limestone samples has been analyzed.