Laboratory investigation on matrix acidizing for a certain pay zone in Iraq

This work investigates the effect of different concentrations of hydrochloric acid, along with selected additive concentrations, temperature, pressure gradient and retardation of acid on the matrix acidizing treatment of carbonate rocks. The matrix acidizing treatments, in which the acid was injected into cores at a pressure below the fracturing pressure of the formation, were accomplished using an apparatus constructed according to the API recommended practices. Test results have shown that pressure gradient and temperature have significant effect on the acid response coefficients.