天然气工业2017，Vol.37Issue(4)：60-68,9.DOI:10.3787/j.issn.1000-0976.2017.04.008
页岩压裂裂缝网络预测方法及其应用
Methodology of hydraulic fracture network prediction in shale reservoirs and its application
摘要
Abstract
In shale reservoirs,natural fractures are developed,which,together with a complex fracture network induced by hydraulic fracturing,can provide effective pathways for oil and gas flowing.Due to the complex fracture network propagation,however,hydraulic fracture identification and fracturing design optimization are faced with new technical challenges.In this paper,a fracture network propagation model (FNPM) was established according to hydromechanics and fracture mechanics theory.In this model,the interaction between hydraulic fractures and natural fractures and the effect of stress shadow between fractures are considered comprehensively.By virtue of this model,fracture propagation direction,fracture network geometry,and propped fracture area in different conditions (e.g.mechanic parameters and natural fractures) can be predicted.Based on theoretical simulation and practical application,some conclusions are reached.First,stimulated fracture network propagation is controlled by multiple factors.For example,ground stress difference,cluster spacing and net pressure determine the stress shallow effect,and the interaction mechanism between natural fractures and hydraulic fractures decides the complexity of induced fracture networks.Second,when the ground stress difference is identical,the smaller the cluster spacing,the stronger the stress shadow effect.As a result,hydraulic fracture propagation is deviated from the main stress direction,and fracture width is decreased,which are unfavorable for sand pumping.Third,the lower the internal friction coefficient of natural fractures and the included angle between natural fractures and hydraulic fractures are,the higher the net pressure,and the more easily the natural fractures can be opened or sheared,consequently the more complex the stimulated fractures are.And fourth,the predicted fracture propagation direction and fracture length are in good agreement,but they are locally different in some fracturing sections due to the development difference of natural fractures.The fracture prediction method proposed in this paper provides a technical support for induced fracture identification and later fracturing design of shale reservoirs.关键词
页岩/储集层/天然裂缝/水力压裂/裂缝网络扩展模型/预测/裂缝扩展方法/几何尺寸/支撑裂缝面积Key words
Shale/Reservoir/Natural fracture/Hydraulic fracturing/Fracture network propagation model (FNPM)/Prediction/Fracture propagation method/Geometry/Propped fracture area引用本文复制引用
尹丛彬,李彦超,王素兵,熊雨然,何封,秦俐..页岩压裂裂缝网络预测方法及其应用[J].天然气工业,2017,37(4):60-68,9.基金项目
国家科技重大专项“水平井压裂设计优化系统”(编号:2016ZX05023001). （编号:2016ZX05023001）
