摘要
为有效提高井下流量计流量校准精度,落实在一定流量校准区间或特定流量校准点出现示值超差或偏差的问题,采用基于雷诺数的流体力学临界流量方程数学推导模型,确定了按流型流量区间、临界流量、流量校准曲线拐点、流道切换点等进行流量校准点选取新原则,考虑了井下流量计校准影响因素,实施了流量校准点优化设计新方法。流量校准点采用新方法后流量校准结果表明,在流量校准精度上,流量曲线标定方程相关系数R较未采用流量校准点优化设计前明显提高;在流量曲线台阶平稳性上,150支井下流量计流量曲线台阶平稳率平均达80%以上;在流量校准上限选定上,当测量上限不大于100 m^3/d,150支井下流量计一次校准成功率平均达80%以上;当测量上限大于100 m^3/d,一次校准成功平均达90%以上,流量校准上限不同,一次校准成功率有所不同,流量校准上限越高,一次校准成功率越高。流量校准点优化再设计,有效规避一定流量校准区间或特定流量校准点,为提高流量校准质量提供可借鉴方法。
In order to effectively improve the flow calibration accuracy of downhole flowmeter, and solve the problem that the indication value is out of tolerance or deviation in a certain flow calibration interval or a specific flow calibration point, the mathematical derivation model of critical flow equation based on Reynolds number is used to determine the new principle of selecting flow calibration points according to flow pattern and flow interval, critical flow rate, inflection point of flow calibration curve and channel switching point This method takes the influence factors of downhole flowmeter calibration into account, and implements a new method of flow calibration point optimization design. The flow calibration results show that the correlation coefficient R of the calibration equation of the flow curve is significantly improved compared with that before the optimization design of the flow calibration point. In terms of the step stability of the flow curve, the average stability rate of the 150 downhole flowmeters is more than 80%. When the upper limit of flow calibration is selected, and the upper limit of measurement is not more than 100 m^3/d, the average success rate of one calibration of 150 downhole flowmeters is more than 80%;when the upper limit of measurement is greater than 100 m^3/d, the average success rate of one calibration is more than 90%. The higher the upper limit of flow calibration is, the higher the success rate of primary calibration is. The optimal redesign of flow calibration points can effectively avoid a certain flow calibration interval or a specific flow calibration point and provide a reference method for improving the quality of flow calibration.
作者
刘立
LIU Li(Well Testing Technology Service Branchy PetroChina Daqing Oilfield Co.,Ltd.,Daqing,Heilongjiang 163513,China)
出处
《油气井测试》
2020年第6期8-14,共7页
Well Testing
关键词
井下流量计
校准点
雷诺数
临界流量
校准曲线拐点
流道切换点
Downhole flowmeter
calibration point
Reynolds number
critical flow rate
inflection point of calibration curve
switching point of flow channel
