Conoco drilled and completed a horizontal well in a depleted, high-permeability, oil reservoir. The formation is an unconsolidated, clean sandstone with absolute permeability over 3300 md. The unconsolidated nature of the formation combined with its low pressure and high permeability caused concerns regarding hole stability, fracturing, excessive fluid loss, and differential sticking. To identify the best drill-in fluid for the horizontal section, the evaluation of fluid candidates focused on both drilling properties and formation/completion damage potential. The testing compared fluid performance in standard API drilling fluid tests, low-shear rheology at elevated temperature, dynamic fluid-loss behavior at elevated temperature, and core flow tests. The flow testing was performed with cores from an offset well to simulate damage due to drill-in fluid exposure and evaluate remedial treatment options. Also, a new lab-scale procedure was developed to observe the tendency of pre-packed screens to be plugged by drill-in fluid filter cake and unconsolidated formation sand. In addition to the laboratory testing, a review of the drilling and completion operations is presented, including performance of the drilling fluid at high overbalance pressure (∼ 2600 psi) and the design and execution of subsequent remedial treatments. The production history is discussed and related to laboratory observations regarding cleanup and remedial treatment effectiveness.