地震敏感属性在GY凹陷泥页岩裂缝预测中的应用

Application of Seismic Sensitivityto Shale Fracture Prediction in GY Depression

国内外大量泥页岩裂缝油气藏的不断发现表明,泥页岩裂缝的研究尤为重要,地震数据中提取的地震属性可用来描述储层特征和探测地下异常体。为了确定苏北盆地高邮凹陷LWS次凹页岩储层的有利分布区,总结了高邮凹陷泥页岩裂缝地震响应特征,并利用地震敏感属性对泥页岩裂缝进行识别。首先通过分析过井地震剖面地震响应特征,建立泥页岩正演模拟,对正演结果进行分析并结合时频分析手段开展对比验证,井震结合,优选古近系阜宁组E1f2页1+页2裂缝敏感的地震属性。利用该方法,对古近系阜宁组E1f2页1+页2选择了低频能量属性进行裂缝预测,应用效果与实钻井吻合程度较好,该方法能在平面上较好地预测泥页岩的发育范围。

The continuous discovery of numerous mud shale fracture reservoirs shows that the study of mud shale fractures is particularly important,and the seismic features extracted from seismic data can be used to describe reservoir characteristics and detect underground abnormal objects.In order to determine the favorable distribution area of LWS sub-concave shale reservoirs in GY sag,Subei Basin,the seismic response characteristics of mud shale fractures in GY sag are summarized,and mud shale fractures are identified with seismic-sensitive attributes.This paperanalyses the seismic response characteristics of the cross-well seismic data,establishes mud shale and forward model,compares forward modeling results from the perspective of time-frequency,and optimizes E1f2shale1+shale2 fracture sensitive seismic attributes.By this way,low-frequency energy attribute was selected for the E1f2shale1+shale2 fractures.Results match well with actual drilling.This method can precisely predict the extent of mud shale development within certain areas.