关键词: 水平井, 砾石充填, 数值模拟, 滤失, 参数优化

Abstract: Wire-wrapped screen combined with gravel pack has been recognized as an effective practice for controlling the movement of sand particles from an unconsolidated reservoir into wellbore during production of oil and gas. However,the operation success rate of gravel pack is very low.Based on the analysis of the gravel packing process and mechanism of horizontal well,this paper has discussed the flow resistance in gravel packing horizontal well,and improves the Gruesbeck model by using two phases solid-liquid theory.A horizontal well gravel packing model that consider fluid loss to formation have been established.The effects of all factors on packing efficiency have been analyzed by the calculation results obtained from this model.The results are that (1) in some range,packing efficiency increases with the parameters,such as flow rate,fluid viscosity,the diameter ratio of tailpipe to screen.However,it is not good for gravel packing if these factors are too big.(2) The packing efficiency decreases with the increase of gravel concentration in injected liquid,fluid loss to formation and gravel size.The operation factors can be optimized,and the option design can be made more scientific and rational by this method.As a result,the successful rate of sand control can be enhanced.

Key words: horizontal well, gravel pack, numerical simulation, filtration, parameter optimize