聚合物驱油井结蜡分析及合理热洗周期的确定

DETERMINATION OF PARAFFIN DEPOSITION AND RATIONAL THERMAL-WASH CIRCLE IN PRODUCER DURING POLYMER FLOODING

针对大庆油田聚驱采出井结蜡严重问题,进行了聚驱采出原油和蜡样的族组分析和饱和烃气相色谱测试。结果表明,与水驱相比,油样中的饱和烃含量稍低,而芳烃和沥青质含量稍高,差别很小;蜡样的饱和烃和芳烃含量明显低于水驱,而沥青质含量则很高,差异很大。动态管流模拟试验表明,聚丙烯酰胺有抑制蜡晶形成和沉积作用。数值模拟分析结果表明,聚驱井结蜡速率高,结蜡点在400～600m之间,合理热洗周期应该在30d以内。

For the serious problem of paraffin deposition during polymer flooding in Daqing Oilfield, analyzed the composition of produced crude oil and paraffin, and tested gas chromatogram of satisfied hydrocarbon, compared the results to water flooding, the content of saturated hydrocarbon in oil sample is lower,while the content of aromatic hydrocarbon and asphaltum is higher, but the difference is small; the content of saturated hydrocarbon and aromatic hydrocarbon in paraffin sample is apparently lower,while the content of asphaltum is much higher. Simulation experiment of dynamic pipe-flow shows that polyarylamide (PAM) has effect on inhibiting paraffin crystal forming and deposition. Analysis results of numerical simulation show that paraffin deposit rate is higher in producer during polymer flooding, generally, the paraffin deposit point is at about 400~600 m, and Rational thermal-wash circle should be less than 30 days.