Abstract
Matrix acidizing is commonly used as a well stimulation process for improving the original matrix permeability of carbonate reservoirs. Acid stimulation treatment is also used for removal of formation damage resulting from drilling, injection, or production operations. In matrix acidizing, deep penetration of wormholes around the well bore is formed.
For successful acid treatment, it is necessary to determine the optimum acid volume and concentration needed.For obtaining the maximum stimulation permeability for the treated zone, experimental studies should be conducted on actual carbonate cores to estimate the optimum acid concentration and the injection volume of acid to improve the permeability of the damaged area. It was concluded that the acid performance curve, which is represented by cumulative acid pore volume versus stimulation ratio, could be determined experimentally for each reservoir to be treated. This curve can be used for the determination of the required acid pore volume to be injected into the reservoir.
The results of this study indicate that there is an optimum acid volume to be injected in order to produce maximum rock stimulated permeability. Excessive injected acid volume more than the optimum value will produce an adverse effect of lowering the permeability of the stimulated core. A new correlation technique for converting acid core data to field conditions is presented in this study.