基于预测控制的双闭环智能井优化控制方法研究

The research of new real time optimized control system for oil production is proposed for the smart wells which are installed with the real time Permanent Downhole Gauge and automatically control processing device.The whole real time optimized control system is comprised with two stages closed loop feedback system which includes Automatic adjustment loop and parameter optimization loop.In the parameter optimization loop, the digital filtering approach is applied for filtering and reducing the real time measured Downhole wellbore parameter. The reservoir optimal model will be automatically adjusted in terms of the processed real time data. The reservoir optimal model based on the optimal method of dynamic moving optimization can dynamically optimize the flow pressure, production rate or injection rate of different segment or different reservoir layer during the production of reservoir.In the automatic regulating loop, the controller is designed with predictive control theory. The real time down-hole valve open area of different segments or different reservoir layers can be automatically calculated in order to effectively execute the optimal reservoir production parameter from parameter optimization loop.The inventive real time optimization control system for smart well can improve the precision of model with the real time monitoring data and give a quick and effective response when the reservoir parameter suddenly change or the reservoir is interfered. It can also improve the recovery rate, decrease production costs and workloads and maximize the economic benefit.

针对在井下安装了实时监测的永久仪表以及能够实现自动操作的控制和处理设备的智能井研究设计采油实时优化控制系统。整个实时优化控制系统采用两级闭环反馈回路：自动调节回路和参数优化回路。在参数优化回路中，利用数字滤波的方法对实时测量的井底油藏参数数据进行滤波和抽稀；油藏优化模型利用处理后的数据进行实时自动校正；动态滚动优化可以基于校正后的油藏模型动态自动优化井底各分支或层段的流压、产液量或注水注气量等生产过程中的重要的参数。在自动调节回路中，利用预测控制理论设计控制器，实时自动计算出井底各分支或层段的流量调节阀门的开度，使得参数优化回路中的油藏生产参数的优化结果能够有效实施。通过智能井采油的实时优化控制系统可以有效利用实时监测数据提高模型精度；及时有效的对油藏干扰和油藏参数的突变做出响应；减少工作量，降低生产成本；提高最终采收率、经济效益最大化。

进入21世纪以来，随着我国国民经济的飞速发展，对于能源的消耗日益增加，如何提高油藏的最终采收率同时减少成本消耗一直都是采油工程中关注的热点问题。随着石油开采中出现的智能井的应用,井控由地面转移到地下，有效提高单井或井场的的经济效益。为了解决地层物理属性难以准确获得以及流体流动的强非线性给井下控制带来的困难,研究了基于预测控制的双闭环智能井优化控制方法。研究实现的基于预测控制的双闭环智能井优化控制方法，在自动调节回路中利用预测控制理论设计控制器，实时自动计算出井底各分支或层段的流量调节阀门的开度，使得参数优化回路中的油藏生产参数的优化结果能够有效实施。为了验证实现的控制方法的准确性，以北海油田某区块的实测数据为例进行了仿真研究。该研究有效利用实时监测数据提高模型精度，及时有效的对油藏干扰和油藏参数的突变做出响应，减少工作量并降低生产成本，有利于提高最终采收率和经济效益。