大牛地气田压裂水平井压裂液返排率研究

摘要

准确预测压裂液返排率是压裂后排液阶段评价储层压裂效果的重要内容.依据离子浓度分析法,提出了实际压裂液返排率计算模型,并对大牛地气田压裂水平井实际压裂液返排率进行了计算分析.结果表明,实际压裂液返排率随返排时间的增加而趋于稳定,此时质量浓度不再变化,可结束试气工作,从而达到缩短试气周期、降低施工成本的目标;当质量浓度稳定时结束压裂液返排,压后返排率与实际压裂液返排率之间呈线性关系,可根据该关系预测实际压裂液返排率,进而快速评价水平井压裂效果.%Accurate prediction of the flowback rate of fracturing fluids is an important component in evaluating reservoir fracturing result.On the basis of ion concentration analysis method,a model of fracturing fluid flowback rate was proposed and the flowback rate of the horizontal wells in Daniudi gas field were calculated.The results show that the flowback rate tends to be stable upon some time elapsing.At this time,the mass concentration of the chloride ions no longer changes,so the work of gas testing can be ended to shorten the testing time and cut down the operation cost.The flowback rate and the actual flowback rate have a linear relation when the flowback is finished and the concentration of the chloride ions is stable.The flowback rate can be predicted according to the linear relation,and the fracturing effect of the horizontal wells can be evaluated quickly.