油井出砂后期多级防砂技术级数研究

Multiple Sand Control Technology in Late Stage of Sand Production

油井出砂是油田注水开发进入高含水期普遍存在的问题。针对现有的防砂方法在油井出砂后期存在防砂效果差、有效期短的问题,提出了油井出砂后期多级防砂技术,并在已有防砂技术的基础上,建立了油井出砂量模型、出砂临界压力模型和非均质性地层渗流模型来优化砾石充填的级数,系统研究了地层亏空半径、地层出砂量、砾石在亏空地层充填级数的确定因素,利用岩石力学和井壁稳定因素建立了一套完整的数学预测模型,为多级防砂技术在油田的推广和应用提供了理论依据。

Sand production is a widespread problem for waterflooding oilfields with high water cut. For the,problems of poor sand control results in existing methods and limited effective period, a multiple sand control technology was proposed. A new sand production model was developed based on the existing sanding control techniques. Critical drawdown pressure model and fluid flow model in heterogeneous formations was used to optimize gravel packing. In addition, formation voidage radius, sand production, number of gravel packing in voidage formation were studied systematically. A complete set of mathematical prediction model which was established using rock mechanics and borehole stability factors provides a theoretical ba- sis for promotion and application of multi sand control techniques in oilfield.