裂缝与井筒成任意角度的压裂水平井产能公式

The productivity formulas of horizontal wells intercepted by multiple fractures with arbitrary angles in gas reservoirs

基于低渗透气藏压裂水平井稳态产能模型,根据复位势理论,建立单条裂缝的平面势分布模型,运用势叠加原理和坐标变换方法,结合实际储层气体性质,建立裂缝与井筒成任意角度时,低渗透气藏压裂水平井稳态产能模型,在Visual Basic 6.0编程环境下,对模型进行求解,获得了压裂水平井产量.通过气藏开发实例计算分析表明,裂缝倾斜角度、水平段长度和裂缝半长是影响低渗透气藏产能的主要因素,而裂缝导流能力对其影响不大.在增产施工中,应尽量压开垂直裂缝,优化水平段长和裂缝长度,以获得更好的增产效果.

This paper presents a new mathematical model for studying the steady-state productivity of horizontal wells in low permeable gas reservoirs. Based on the complex potential theory, a plane potential distribution model of a sin- gle fracture was established. Following the superposition principle and the coordinate transformation method, the pro- ductivity model of a fractured horizontal well in low permeability gas reservoirs was established, which takes into ac- count multiple fractures at any angle to the wellbore. The productivity dynamics of horizontal wells were then oh-tained with Visual Basic 6.0, and the reliability of this model was confirmed through a field case. Result shows that compared with fracture conductivity, the angles between fractures and wellbore, the length of the horizontal well- bore, and the half-length of fractures have primary influences on the production of fractured horizontal wells in low permeability gas reservoirs.