Abstract
The purpose of matrix stimulation in carbonate reservoirs is to bypass damaged areas and increase the effective wellbore area. This can be achieved by creating highly conductive flow channels known as wormholes. A further injection of the acid will follow a wormhole path where the permeability has increased significantly, leaving substantial intervals untreated. This problem can be more significant as the contrast in permeability increases within the target zones. Diverting materials, such as viscoelastic-surfactant (VES) based acids, play an important role in mitigating this problem. The acid-injection rate was found to be a critical parameter to maximize the efficiency of the use of VES-based acids as a diverting chemical in addition to creating wormholes. It was found that the maximum apparent viscosity, which developed during VES-based-acids injection, occurred over a narrow window of acid-injection rates. Higher injection rates were not effective in enhancing the acidizing process
| Original language | English |
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| Journal | SPE Journal |
| State | Published - 2014 |