地层应力敏感性对脱砂压裂油井产能动态预测的影响分析

The Effect of Formation Stress Sensitivity on Productivity Performance Forecasting of Tip-screen-out Fractured Well

压裂工艺已经成为油井增产的主要措施,对油井压裂效果的评价也日益重要。作为压裂效果评价的组成部分,生产动态预测研究受到越来越多的重视。端部脱砂压裂是疏松砂岩油气藏开发的一项新技术,对该类油藏进行压后产能模拟预测具有重要作用。在传统渗流理论的基础上,除考虑重力、毛管力、井壁污染等因素外,通过引入疏松砂岩油藏渗透率、孔隙度,建立新的脱砂压裂井三维两相生产动态预测模型。利用该模型,研究疏松砂岩油藏应力敏感性对压裂油井产能动态预测的影响,可知:油藏应力敏感性显著影响油井压后生产动态;地层渗透率和孔隙度越大,其应力敏感性对油井生产动态的影响也越大;但孔隙度变化对压后产能的影响小于渗透率变化的影响。渗透率是油藏应力敏感性因素的主要影响参数。通过与压裂井实际生产曲线对比,显示该模型符合率较高,能够比较真实、准确的预测油井压后生产动态。

Hydraulic fracturing has been the main treatment of well stimulation ,and the evaluation of its el- fect is becoming more important.As a part of evaluation of posffracture response,more and more attention has been paid to the research on the forecast of production performance.Tip Screen Out fracturing （TSO） is a new technology of developing the unconsolidated sand oil-gas reservoirs that has important role on the simulated productivity forecasting of wells after fracturing.Based on theory of traditional filtration theory,a new three-di- mension and two-phase model of performance forecasting for the tip-out-screen（TOS） fractured wells is estab- lished in this paper combined with the dynamic model of permeability and porosity except for gravity ,capil- lary force, skin coefficient and so on.The effect of formation stress sensitivity on productivity performance fore- casting of the fractured wells is analyzed by this model.The result shows that the production performance of the fractured wells is influenced significantly by the formation stress sensitivity ,and the bigger formation per- meability and porosity has the greater influence,but the influence of the porosity on the productivity after fracturing is less than that of the permeability.Permeability is the major influencing parameter of stress sensitivity.Reliability of the model has been proved by a comparison with actual production curve of the fractured well.