Some of the completion failures are due to screen plugging. A number of remedies have been adopted by the industry to cleanup plugged screens. However, these cleanup methods are not investigated under downhole conditions. This study utilized a large-scale radial flow-loop to study prepacked screen cleanup under downhole conditions. First, the original permeability of each screen was measured with 10 ppg NaCl brine solution. A sized carbonate drill-in-fluid was then formulated and pumped for 3 hours and at a constant differential pressure of 60 psi across the screen, simulating a screen run in a wellbore. Inlet and outlet samples were collected for size distribution analysis and removal efficiency calculations of each screen. Each plugged screen was then subjected to a cleanup method such as acidizing, use of enzyme breaker, backflow, or a combination of these methods. Following cleanup, the permeability of each treated screen was measured with 10-ppg NaCl brine solution and compared to the screen's original permeability. The degree of plugging and percent area open to flow was evaluated based on the retained permeability of each screen.

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