利用卡尔曼滤波和人工神经网络相结合的油藏井间连通性研究

油藏连通性的认识对于制定合理的开发调整方案和提高水驱油藏采收率具有重要意义。基于注采井的生产动态数据,建立一种卡尔曼滤波和人工神经网络相结合的分析方法,对油藏井间动态连通性进行定量表征研究。考虑到注入数据的噪声污染和注入信号在地层传播过程中的时滞影响,分别利用卡尔曼滤波算法和非线性扩散滤波器对注采数据进行预处理,从而减少注采数据对机器学习模型的干扰,提高连通性分析的准确性。基于预处理后的历史注采数据,对以生产井产液量为响应,注水井的注水量为输入的人工神经网络进行训练和参数优化,模拟和挖掘注采系统中的井间连通关系。通过对训练好的模型进行参数敏感性分析,量化油藏井间连通程度。应用所建模型和方法分析了均质、各向异性、包含封闭断层、具有高渗透带的4种典型特征油藏和实际非均质油藏的井间连通性。计算结果与油藏地质特征高度吻合,验证了该方法的实用性,可作为量化注采系统连通状况的有效方法。

Research on interwell connectivity of oil reservoirs based on Kalman filter and artificial neural network

The understanding of interwell connectivity of oil reservoirs is of great significance for the formulation of reason able development and adjustment plans and the improvement of water-driven reservoir recovery.Based on dynamic data of injection-production well,an analysis method combining Kalman filter and artificial neural network is established to quan titatively characterize the dynamic interwell connectivity in reservoir.Considering the noise pollution of the injection data and the time-lag effect of the injection signal in the formation propagation process,the Kalman filter algorithm and the non linear diffusion filter are used to pre-process the injection-production data,thereby reducing the effect of injection-produc tion data on the machine learning model,and improving the accuracy of connectivity analysis.Based on the pre-processed historical injection and production data,the artificial neural network taking the oil production rates of producers as the re sponse and the water injection rates of injectors as the input is trained and the parameters are optimized,and the interwell communication relationship in the injection and production system is simulated and excavated.Through the parameter sen sitivity analysis of the trained model,the degree of interwell connectivity in reservoirs is quantified.The model is applied to analyze the interwell connectivity in four types of reservoirs with representative characteristics such as homogeneity,anisot ropy,closed faults,high permeability zones and one real heterogeneous reservoir.The calculation results are highly consis tent with the reservoir geological features,indicating that this method has good practicability and reliability.It can be applied to effectively quantify the connectivity of injection and production system.