Determining optimum acid injection rate for a carbonate gas reservoir and scaling the result up to the field conditions: A case study

• Five core sample groups of a carbonate gas reservoir were acidized using a coreflood apparatus.
• Optimum acid injection rate for stimulation of a gas reservoir was obtained.
• 10 feet wormhole radius obtained and skin factor decreased to −3.5 from original skin 2.
• Obtained data could be used as input to simulate acidizing process.

Acidization is a common but complex stimulation method which improves significantly production rate especially in the carbonate reservoirs. To achieve this technique successfully one requires to perform extensive laboratory study which includes evaluation of many different parameters such as temperature, pressure, and rock mineralogy of the reservoir plus the effect of chemical diverters in the zones with high contrast in permeability prior to field application.In this study, several core samples of an Iranian carbonate gas reservoir were acidized using a core-flood apparatus. Experimental results were used to construct the acid efficiency curve. Finally, this curve was used to scale up the obtained optimum injection rate to field conditions. The experimental data produced during these tests, can be also used as source for tuning numerical models that are capable to address behavior of acid flow in porous media.

Figure optionsDownload high-quality image (102 K)Download as PowerPoint slide