基于分相能量守恒研究产水气井携液能力

Study on Fluid-carrying Capability for Liquid Loaded Gas Wells Based on Partial Phase Energy Conservation

为研究产水气井井筒中的携液流动规律,正确预测气井产液量,指导排水采气方案设计与实施和构建井筒/油藏耦合模型,采用分相能量守恒方程建立一套专门用于计算气井携液能力计算的管流模型,并设计一套灵活的求解方法,能够在已知两端压力和气相流量的前提下对产液量进行直接求解。经与实测管流资料进行对比计算发现,在计算大产气量的两相管流时,所用模型的计算精度高于经典的多相管流模型。使用该模型对气井携液能力进行敏感性分析,表明产液气井存在携液能力最强的产气量点,在制定气井生产方案或进行排水采气优化设计等工作时应当给予充分的注意。

In order to study the fluid-carrying capability in gas wells,a pipe flow model was developed.This model was aim to predict liquid production rate correctly and guide the design and implementation of drainage gas recovery programs and establishment of the coupling model of wellbore and reservoir.The proposed pipe flow model was on the basis of the fractional conservation of energy,which treated gas as compressible phase and liquid as incompressible phase separately.A targeted solution method was presented,which could be used in this model to calculate liquid production rate directly with outlet pressure,inlet pressure,gas flow rate.In comparison with the classical method,the proposed model was more precise in calculating the wellbore pressure distribution,especially in the case of high gas production rates.Finally,the sensitivity analysis of the parameters influencing the fluid-carrying capacity of gas wells was carried out.It turns out that thereis an optimal gas production rate with the greatest fluid-carrying capability and this should be well considered when making gas well production plans and optimization of drainage and gas production design.