基于施工参数的临界出砂速率预测模型

Prediction model of critical sand production rate based on fracturing operation parameters

水力压裂气井出砂防治仅针对生产制度控砂以及地面设备除砂,无法预测不同压裂工艺对于出砂程度的影响。压裂防砂设计从SM模型出发,将压裂施工参数与临界出砂速率建立联系,形成基于压裂施工参数的临界出砂速率预测模型,分析了压裂液黏度、泵注排量、砂液比、支撑剂密度、支撑剂粒径对于临界出砂速率的影响。结果表明适当提高泵注排量,增加压裂液黏度,选择合适的砂液比能够有效提高临界出砂速率,防止支撑剂失稳回流。涪陵页岩气田焦石坝区块4口水平井现场应用,压后支撑剂回流现象得到明显改善,产气量得到有效提升,平均单井出砂量比前期两口井减小了80.5%。该模型可指导现场压裂方案优选,将防砂治砂前移到压裂设计阶段,从源头上减少出砂风险。

Sand control of hydraulic fracturing gas wells is realized only by virtue of production system and surface equipment,but the impacts of different fracturing processes on the degree of sand production cannot be predicted.In this paper,based on the SM model,the fracturing operation parameters were correlated with the critical sand production rate to form a prediction model of critical sand production rate based on fracturing operation parameters.The effects of fracturing fluid viscosity,pump displacement,sand-liquid ratio,proppant density and proppant particle size on the critical sand production rate were analyzed.The results show that properly increasing the pump displacement,enhancing the viscosity of fracturing fluid and selecting appropriate sand-liquid ratio can effectively improve the critical sand production rate and prevent the proppant influx.The field application in four horizontal wells in Jiaoshiba block,Fuling shale gas field,revealed that the post-frac proppant influx was controlled effectively,the gas production was enhanced effectively,and the average sand production per well was 80.5%lower than two wells fractured previously.The model can guide the optimization of site fracturing scheme and allows sand control to be considered at the fracturing design stage,so as to reduce the risk of sand production from the very beginning.