Study on Optimal Water Control Methods for Horizontal Wells in Bottom Water Clastic Rock Reservoirs

The segmented water control technology for bottom water reservoirs can effectively delay the entry of bottom water and adjust the production profile. To clarify the impact of different methods on horizontal well production with different reservoir conditions and to provide theoretical support for the scientific selection of methods for bottom water reservoirs, a numerical simulation method is presented in this study, which is able to deal with wellbore reservoir coupling under screen tube, perforation, and ICD (Inflow Control Device) completion. Assuming the geological characteristics of the bottom-water conglomerate reservoir in the Triassic Formation of the Tahe Block 9 as a test case, the three aforementioned completion methods are tested to predict the transient production characteristics. The impact of completion parameters, reservoir permeability, bottom-water energy, and individual well control on the time to encounter water in horizontal wells (during a water-free production period) is discussed. A boundary chart for the selection of completion methods is introduced accordingly. The results show that the optimized ICD completion development effect for heterogeneous reservoirs is the best, followed by optimized perforation completion. Permeability is the main factor affecting the performances of completion methods, while bottom water energy and single well controlled reserves have a scarce impact. The average permeability of the reservoir is less than 500 mD, and ICD has the best water control effect. If the permeability is greater than 500 mD, the water control effect of perforation completion becomes a better option.