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酸液滤失量是压裂液滤失量的数倍，在裂缝中穿透的距离将对酸化效果产生重大影响，在碳酸盐岩酸压施工的模拟计算中，它是必须考虑的因素。对碳酸盐岩酸压中酸液有效作用距离的预测方法进行了改进，通过考虑酸液流动过程中裂缝横截面积随时间和空间的变化，采用输运公式建立了酸液在缝中的流速分布方程，引入了δ函数，考虑了注入点的影响。同时，根据实际情况提出了根据酸液滤失判断有效作用距离的新方法，采用反应与滤失双重标准予以判定，使得酸液有效作用距离的计算更合理。模型考虑了同离子效应、温度场、酸岩反应热等因素的影响，较以前的模型更为准确地预测了酸液有效作用距离，从而为施工参数设计和施工效果预测提供了依据。

AN IMPROVEMENT ON THE METHOD FOR FORECASTING THE EFFECTIVE ACTION DISTANCE OF ACIDIZING FLUID

??The filtration of acidizing fluid is several times as much as that of fracturing fluid and the penetration distance of acidizing fluid in fractures will produce an important effect on acidizing result,which should be considered in the analog computation of acidizing-fracturing operation in carbonate rocks.The method for forecasting the effective action distance in acidizing-fracturing operation in carbonate rocks is improved.In consideration of the fact that the cross-sectional area of fracture changes with the time and space in the flowing course of acidizing fluid,the flowing speed distribution equation of the acidizing fluid in fractures is set up by use of transport equation,in which the effect of injecting point is considered and the function ?? is introduced.At the same time,a new method for judging effective action distance is put forward on the basis of the filtration of acidizing fluid and according to actual situation,in which the double standards of reaction and filtration are used to judge,making the calculation of the effective action distance of acidizing fluid more reasonable.For the model,the effects of such factors as homo ionic effect,temperature field and reaction heat generated in acidifying rocks etc.are considered,which,by comparison with previous model,can more accurately forecast the effective action distance of acidizing fluid,thus providing a basis for the design of operation parameters and the forecast of operation result.