Drawdown-Driven Sand Production and Screen Plugging: Implications for Casing Integrity in Gas-Lift Wells

Gas-lift operation in weakly consolidated sandstone can increase drawdown and aggravate sand-related completion impairment, while sparse surveillance often prevents mechanism attribution. This study develops an evidence-graded, field-constrained workflow for screening drawdown-driven sand response, scenario-based screen impairment, and potential casing-integrity consequences in a dual-tubing, packerless gas-lift well. Normalized liquid-rate loss, surface sand concentration, and pressure deviation are combined in a field-response score SFR, whereas the effective open-area ratio (λ) and local velocity ratio (Iv) are evaluated separately as sensitivity variables. The workflow was applied to a six-stage sequence from an anonymized South Caspian offshore well. At Stage 3, sand concentration increased 15-fold, while liquid production declined by 11.7%. Stage 4 combined a 50.0% rate decline, an 80-fold sand increase, the maximum pressure deviation, and the highest SFR (0.792). At Stage 5, the rate declined by 66.7% and sand increased 150-fold, while SFR decreased to 0.593 because the pressure component weakened. Prescribed (λ) values of 0.25 and 0.10 yielded (Iv) values of 2.00 and 3.33. These scenarios demonstrate possible local inflow concentration during declining total production but do not confirm screen plugging or casing deformation. The workflow supports surveillance prioritization pending calibration with downhole pressure, screen differential pressure, intervention outcomes, and caliper data.