聚合物驱后强碱三元复合驱结垢规律及清防垢配套技术研究

Research on the Scaling Regularity & the Matching Technology of Scale Removaland Prevention for Strong Base ASP Flooding after Polymer Flooding

为探索聚合物驱后强碱三元复合驱进一步提高采收率,延长检泵周期,对南三东葡I1-4油层聚合物驱后强碱三元复合驱采出井结垢规律及清防垢配套技术进行研究。应用数理统计方法分析采出液离子质量浓度的变化,结合区块的采出程度和优势渗流通道发育等因素,总结聚合物驱后强碱三元复合驱的结垢规律。研究结果表明,聚合物驱后强碱三元复合驱存在优势渗流通道的采出井见垢早、采出液离子质量浓度变化快的结垢规律,没有优势渗流通道的采出井结垢规律与普通强碱三元复合驱结垢规律一致。针对该结垢规律,筛选出个性化的清防垢配套技术。措施后平均检泵周期提高到220天以上,延长180天,满足了聚合物驱后强碱三元复合驱试验的要求,对大庆油田聚合物驱后三元复合驱推广提供了采出井清防垢配套技术储备。

In order to explore the strong base ASP flooding technology for further improving oil recovery ratio and prolonging the pump inspection cycle after polymer flooding,the scaling regularity of producers by the strong base ASP flooding and the matching technology of scale removal and prevention have been conducted in the PI1-4 oil layer of Nansandong Block after polymer flooding.By using the mathematical statistics method to analyze the change of ion mass concentration in produced liquid,and combining the production degree of the block with the dominant seepage channel,etc,the scaling regularity of strong base ASP flooding has been summarized after polymer flooding.Research results showed that the producers with dominant seepage channel could appear the scale easily by the strong base ASP flooding after polymer flooding,and the ion mass concentration changed rapidly in the produced liquid.However,for those producers that have no dominant seepage channel,the scaling regularity was similar to the wells of common strong base ASP flooding.According to the scaling regularity,a special matching technology of scale removal and prevention has been selected.After taking the measures,the average pump inspection cycle was increased to more than 220 days,i.e.prolonging 180 days,which has met the requirements of strong base ASP flooding test after polymer flooding.It provided a matching technical storage for scale removal and prevention as well as promoting the strong base ASP flooding application after polymer flooding in Daqing Oilfield.