The selective acidizing operation using a retrievable inflatable packer and the extensive acid stimulation of the horizontal Jufair-9 well in the Sepehr-Jufair field (Ilam reservoir) with two open-hole laterals measuring approximately 4,900 feet in length and 9,700 feet in depth has been successfully completed. According to Mr. Salimi, Petroleum Engineering Manager at PECO, this operation required a thorough evaluation of formation damage, precise engineering design, and close coordination among various project teams. Through innovative and flawless execution, PECO achieved a groundbreaking milestone in open-hole horizontal well acid stimulation, utilizing maximum local knowledge, indigenous technologies, and a commitment to efficiency.  

Key Engineering Measures and Actions Taken:  

- Conducting laboratory tests considering the estimated operation time.  

- Performing selective acidizing using coiled tubing and a retrievable inflatable packer.  

- Treating damaged zones while preserving formation integrity.  

- Successfully injecting over 50,000 gallons of stimulation fluids within 36 hours using coiled tubing.  

- Executing matrix acidizing and injecting more than 110,000 gallons of stimulation fluids.  

- Enhancing injectivity using diverters to optimize acid distribution across both laterals.  

Operational Challenges and Solutions:  

- Planning and managing the deployment of the required fleet and equipment at the Jufair-9 wellpad in the presence of a rig.  

- Handling the large volume of chemicals and fluids.  

- Utilizing advanced retrievable inflatable packer technology in a horizontal well with two open-hole laterals of 4,900 feet each to ensure effective and targeted acid distribution.  

Operation Results:  

- Increase in Injectivity Index (II):  

  - After selective acidizing: More than 2.5 times improvement.  

  - After matrix acidizing: 2 times higher than selective acidizing, resulting in an overall increase of about 5 times compared to pre-acidizing conditions.  

Key Takeaway:  

The innovative combination of selective acidizing and matrix acidizing serves as an effective and replicable model for complex open-hole horizontal well completions, offering a new perspective for the development and optimization of acid stimulation operations.