Experimental Evaluation of Dispersion Coefficient of Water Injection Process in One Iranian Heterogeneous Carbonate Reservoir

فاقد چكيده فارسي

Mixing of injection and formation waters could be resulted in scale deposition due to incompatibility of mixed waters. Calcium sulphate is one of the common scales which will be formed in porous media which reduces its permeability as well as the success of continuous water injection due to decrease in injectivity of reservoir.Prediction of calcium and sulphate concentrations and the rate of scale deposition need the dispersion coefficient of mixed waters. This parameter is sometimes will be estimated with neglecting the effect of porous media or with using foreign tracers which might affect the rate of scale deposition.This work has improved both experimental method to measure the dispersion coefficient and also prediction of concentrations of tracers in porous media. The strength of dispersion coefficient calculation in this work is using the suitable tracers which will not affect the scale precipitation by mixing both incompatible waters.The results of modelling in this work show that the standard diffusivity equation which is the common method of predicting the concentration of ions in porous media cannot give reasonable results for heterogeneous rocks so another model has been suggested.The concentrations of sodium and chloride ions here have been predicted by the standard diffusivity model and also with the capacitance model which considers the dead-end volume in calculations. The engaged methodology predicted the experimental data with good accuracy and suggests the application of the capacitance model for heterogeneous carbonate rocks.