压裂液返排的数值模型优化

摘要

压裂液返排对压裂施工的效果影响重大，目前我国在压裂液返排的建模方面主要是针对常规砂岩储层，由于模型的复杂程度被简化，计算结果易出现误差而偏离实际。本文根据流体的质量守恒定律和裂缝形态变化规律对压裂液返排数值模型进行优化，并利用体积平衡原理求解该模型，通过压力变化对裂缝闭合时间给出定量判断，为后续放喷油嘴时的尺寸选择提供理论依据。%The fracturing fluid flowback has great influence on fracturing. The modeling of fracturing fluid flowback in our country is mainly aimed at the conventional sandstone reservoirs, because the complexity of the model has to besimplified, the calculation results is prone to error and deviation. This paper optimized the fracturing fluid flowback modelaccording to the law of conservation of mass flow and the fracture morphology changes, and then used the volume balance principle to solve the model. Giving the quantitative judgment through the pressure change on the crack closing time can provide a theoretical basis for the subsequent discharge nozzle size selection.