微裂缝发育储层分段压裂水平井裂缝参数预测

目前对微裂缝发育储层实施水平井分段压裂改造后的裂缝监测手段普遍存在监测精度低、成本高、现场实施难度大等缺点，亟需找到一种方便、快捷、现场适用的解释手段和方法。基于微裂缝发育储层多段压裂水平井三线性渗流规律，建立了多段压裂水平井渗流模型，进行Laplace变换，推导得到微裂缝发育储层多段压裂水平井不同特征流动段产量公式，并利用现场油井日常生产数据，分析产量变化曲线不同特征段的特点，求解得到了微裂缝发育储层多段压裂水平井裂缝参数（人工裂缝长度、人工裂缝导流能力和天然微裂缝区渗透率）。将模型计算得到的裂缝参数分别与3口水平井的现场微地震监测解释结果进行对比，验证了模型的正确性。研究结果表明：模型计算人工裂缝导流能力与真实值相对误差为1.9%，模型计算人工裂缝长度与微地震监测解释结果基本一致。该方法解释出的多段压裂水平井压后裂缝参数多、方便快捷、准确性高、局限性小，适合油田现场大规模推广应用，对微裂缝发育储层多段压裂压后效果评价、指导增产设计具有重要意义。

A novel method to interpret fracture parameters of multistage fractured horizontal well in reservoirs with micro-fractures

Because of the disadvantages of low accuracy,high cost and inconvenience for field application of current fracture monitoring methods,it is necessary to develop a new approach to monitor the parameters of hydraulic fractures in reservoirs.Based on the theory of tri-linear fluid flow in porous media,a novel seepage model was developed for multistage-fractured horizontal wells in reservoirs with micro-fracture.Laplace transform was performed to derive well production rate formulas for different typical flowing periods.The field daily production data were used to analyze the typical characteristics of diffe-rent segments of the production curve and to solve the model for fracture parameters including hydraulic fracture length,hydraulic fracture flow conductivity and permeability of natural fracture in the reservoir.The model was validated with the microseismic monitoring data of 3 horizontal wells in the field.The results show that the relative error of the hydraulic fracture flow conductivity between the prediction result and the real value is 1.9%,and the hydraulic fractures lengths from model calculation are in good agreement with the micro seismic monitoring results.With the advantages of conve-nience,rapid interpretation,high accuracy and good adaptability,this method proposed in the paper is helpful to the evalu-ation and design of horizontal well multistage-fracturing stimulation in reservoirs with well developed micro-fractures.