通过地表露头调查、测井曲线、成像测井、钻孔岩心分析等手段分析了新场地区须家河组二段的裂缝发育特征。须二段储层裂缝以低角度裂缝为主，同时发育斜交缝、高角度缝、网状缝等；裂缝走向主要有NEE，NE和SEE 3个方向，可分成构造剪切裂缝、构造张性裂缝和层理缝3种基本成因类型。在此基础上，根据基础地质资料和构造演化特征建立三维数值计算模型，结合构造地质学关于裂缝与构造应力关系的理论，同时参考研究区现有岩心观察、测井分析、室内试验结果等资料，确定出研究区裂缝发育分布的预测标准。通过计算结果可知：须家河组二段第七、第四、第二砂组岩层顶板中裂缝主要发育在断裂带附近、翼部较陡的转折端及构造高点区域，以低角度剪切缝为主；在构造高点地区，也发育有较多张性裂缝，其研究结果与实际勘探揭示情况基本一致，说明预测模型具有一定的实际应用和参考价值。%Characteristics of fracture development in the 2 nd member of the Upper Triassic Xujiahe Fm in Xinchang gas field were analyzed through outcrop observation,logging curve,image logging and analysis of borehole cores.The frac-tures in the studied interval are dominated by low angle fractures,followed by oblique fractures,high angle fractures and map cracking.And the strikes are mainly NEE,NE and SEE.The fractures can be divided into tectonic shear cracks, structural tensile fractures and bedding cleavages according to their genesis .On the basis of these studies, a three-di-mensional numerical model of tectonic evolution was built according to the basic geological data and tectonic evolution features.Criteria for fracture identification were established based on theories of structural geology and taking the core observation and well logging analysis,laboratory test results into account.The calculation result shows that the T2(2) x, T2(4) x and T2(7) x sandstone roof fractures mainly developed near the fault zone.In the wing steep turn and structure peak area are main low angle shear fractures.And many tensile fractures are developed in the structure highs.Research results are basically consistent with exploration results, so the conclusion has a certain practical application and reference value.
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