渤海J油田化学驱无因次产液指数的变化规律

Variation Law of Normalized Liquid Productivity Index during Chemical Flooding in J Oilfield of Bohai Bay

针对渤海J油田化学驱过程中部分井产液能力明显下降的问题,运用J油田的有关数据,通过建模计算,分析了聚合物驱与聚表二元复合驱阶段无因次产液指数的变化规律。结果表明:无因次产液指数在聚合物驱阶段先呈上升趋势,聚合物驱见效后开始下降,并在含水率最低点附近出现最低值,而后随着含水率的回返而升高,在聚合物产出质量浓度突破600 mg/L后则止升为降。转为聚表二元复合驱后,各井的无因次产液指数普遍进一步下降。在聚合物驱阶段,受效井无因次产液指数的最大下降幅度为74. 26%,大多数井的下降幅度为40. 00%～60. 00%,平均值为47. 82%。在聚表二元复合驱阶段,受效井无因次产液指数的最大下降幅度为86. 15%,平均值为61. 59%。

To address the considerable reduction of liquid productivity index during chemical flooding in J Oilfield of Bohai Bay,a mathematical model of normalized liquid productivity index is constructed and applied to investigate its variation law during polymer and surfactant polymer flooding.The results show that the normalized liquid productivity index first increases as polymer injection is implemented;then decreases when polymer flooding takes effect,and reaches its lowest value at around the lowest water cut.And the index rebounds later when water cut turns to increase,but stops increasing and decreases when the produced polymer concentration grows cross 600 mg L.Finally the normalized liquid productivity index decreases when surfactant polymer injection starts.The maximum relative reduction of normalized liquid productivity index during polymer flooding is 74.26%with 40.00~60.00%for most wells and the average value is 47.82%.While the maximum relative reduction of normalized liquid productivity index during surfactant polymer flooding is 86.15%and the average value is 61.59%.