充填防砂井排砂解堵安全负压值设计方法研究

Study on Design Method of Safety Negative Pressure Value in Sand Drainage and Plug Removal of Gravel-packing Sand-control Well

针对砾石充填防砂井油层上下存在薄隔层及水层无法进行高压挤注方式解堵的现状,为改善砾石充填防砂井解堵效果、保障生产安全,对油井排砂解堵安全负压值设计方法进行研究。根据油井采液产生的附加表皮系数修正最小负压值,并以防止储层出砂为原则设计最大负压值,根据Conocophillips负压值设计法对最佳负压值进行设计校核,最终建立油井排砂解堵负压值计算模型。应用上述模型对两口典型井进行排砂解堵负压值设计,其最佳安全负压值分别为5.04 MPa、7.84 MPa,该方法既解除近井地带堵塞又保证储层的稳定性。

There are thin interlayer and water layer above and below the oil layer of gravel-packing sand-control well,and therefore the sand plug can not be removed by high pressure injection.The design method of safety negative pressure value for sand plug removal of the oil wells is studied in order to improve the effect of plug removal of gravel-packing sand-control wells and ensure the safety of production.The minimum negative pressure value is corrected according to the additional skin factor produced by oil well production fluid,and the maximum negative pressure value is designed based on the principle of preventing sand production of reservoir.The negative pressure values for sand plug removal of two typical wells are designed using the above model,and their best negative pressure values are 5.04 MPa and 7.84 MPa respectively.This method can not only remove the sand plug near wellbore area,but also ensure the stability of the reservoir.