超正压射孔动态模拟数学模型

根据超正压射孔(EOP)工艺的机理和技术特点,阐述了超正压射孔的基本过程和增产原理。利用能量守恒方程和井筒液体运动方程,建立了超正压射孔井筒压力动态模拟数学模型;利用裂缝扩展质量守恒和动量守恒原理,建立了地层裂缝动态扩展模型。通过井筒动态模拟和裂缝动态扩展模拟模型耦合求解,获得了井筒压力、裂缝尺寸随时间的动态变化规律,分析了施工参数(包括液柱高度、气柱高度及井口压力)和其他特征参数对施工压力和动态裂缝扩展的影响,提出了EOP工艺设计的基本原则。现场实验验证了模型的正确性和EOP工艺的实施效果。

Dynamic simulation model for extreme overbalanced perforating operation

The technological principle of stimulation and procedures of the extreme overbalanced perforating (EOP) operations were analyzed. The dynamic equations for well bore pressure were derived according to the energy conservation law and gas liquid interface moving features. The dynamic models for the propagation of fractures were also proposed on the basis of mass and momentum conservation laws. These models were applied to simulate the performances of well bore pressure and fracture propagation in the extreme overbalanced perforating operation. The change laws of well bore pressure and fracture dimension with time were obtained by coupling method of dynamic simulation models of well bore pressure and fracture propagation. The effects of operation parameters including wellhead pressure, gas liquid column and formation fluid characteristics on well bore pressure and fracture propagation were discussed. The field application identified the correctness and operation effects of EOP technology. 