分采分输泵工况诊断

WORK CONDITION DIAGNOSTIC METHOD OF SUCKER- ROD PUMPING SYSTEM IN DOUBLE-LAYER SEPARATE RECOVERY

分采分输有杆抽油系统采用特殊的分采泵,利用空心杆和空心杆-油管环空分别作为下部油层与上部油层的油流通道,实现了两层分采、分层计量,为两油层的动态分析和生产管理提供了重要的基础数据。文章针对地面测试示功图唯一,如何模拟上、下两泵工况的这一技术难题,将分采泵分解为上部空心泵和下部管式泵,结合各油层生产数据,使一口油井变成了两口油井,分别预测其地面示功图,获取地面动载荷示功图,将上泵与下泵动载荷示功图采用不同的劈分系数合成光杆示功图,求取在相同位移时与实测示功图动载荷绝对误差最小的劈分系数,进而将实测示功图的动载荷按上下泵分配系数劈分,与对应的上、下泵静载荷结合,得到上、下泵光杆示功图,结合各自条件按波动方程模拟井下泵工况。实例井计算表明该方法具有可靠性和实用性。

The sucker- rod pumping system of double layer separate recovery adopted a special pumping unit and a hollow rod to realize double layer separate recovery and separate layer measurement,so the BFPD and BOPD of each layer could be obtained to provide basic data of dynamical analysis and production management system for either layer.The present diagnosis technique can' t well suit to diagnose the new pumping system work condition.The key to the downhole diagnosis of pumping system lies in obtaining the downhole pump diagrams.The special pumping unit was divided into hollow pump in the above layer and tube pump in the deeper layer.Then two sucker- rod pumping systems were established.The dynamic load card of either system was respectively separated from predicting the surface dynamometer cards of the corresponding system(hollow pump system or tubing pump system).The dynamic load of sucker- rod pumping system in double- layer separate recovery was the sum of dynamic load of hollow pumping system multiplying its weight and that of tubing pumping system multiplying the value which one subtracts the weight of hollow pumping.By optimizing the weight of hollow pumping,the difference of the dynamic load between the computation dynamometer cards and the testing dynamometer cards was minimum.The actual dynamic load of hollow pump system was equal to that of the testing cards multiplying the optimizing weight and the actual dynamic load of tubing pumping system was equal to that of the testing cards subtracts that of the hollow pump system.Of course the dead weight of hollow pump system or tubing pump system was used to get their surface dynamometer card.Then bottom- hole pump dynamometer cards of either system were computed by using the wave equation.The new technology was verified to be credible and practical with one example.