摘要
沿层曲率作为地震属性的一种,不仅有数学几何意义更有着重要的地质意义。和相干体相比,沿层曲率在油气勘探中常被用于刻画地质构造形态及断裂精细解释,特别是在小尺度断裂发育的地区更为有效。而在实际工作中,有时利用沿层曲率所描述的断裂效果不太明显。为进一步明确对于刻画断裂结果的影响因素及其适用条件,以鄂尔多斯盆地Q区Tj9为研究对象,基于Geoeast软件对该区小尺度断裂系统从选取属性、方位角、频带三个方面展开分析。结果表明:(1)曲率比相干体更适用于刻画较小尺度的断层;(2)平面上从平行断裂的方位观测,断裂识别不清晰;从垂直断裂的方位观测,易于识别;(3)在反射层同相轴较强时,中高频段对断裂识别更清楚;在反射层同相轴较弱时,中频段对断裂识别更清楚。因此可以根据不同属性、不同方位角、不同频带对断裂的敏感程度,用不同的数据体解释小尺度断裂,提高对断层刻画的精度,为复杂油气勘探寻找有利区奠定基础。
As a kind of seismic property,the curvature along the layer has not only mathematical geometric significance but also geological significance.Compared with coherent bodies,it is often used in oil and gas exploration to depict geological structures and fine interpretation of faults,especially in areas where small-scale faults are developed.In practical work,sometimes the fault effect described by the curvature along the layer is not obvious.In order to further clarify the influencing factors and applicable conditions for characterizing the fracture results,this work took the seismic horizon Tj9 in Q of Ordos Basin as the research object.Based on Geoeast software,the small-scale fracture system in this area was analyzed from three aspects:attribute,azimuth angle and frequency band.The results show that:(1)Curvature is more suitable for describing small-scale faults than coherent body;(2)In plane,it is not clear to identify the parallel faults from the azimuth observation,and it is easy to identify the vertical faults from the azimuth observation;(3)When the phase axis of the reflector is strong,the fracture identification in the medium and high frequency band is more clear.When the in-phase axis of the reflector is weak,the fracture identification in the medium frequency band is more clear.Therefore,according to the sensitivity of different attributes,different azimuth angles and different frequency bands to faults,different data bodies can be used to explain smallscale faults,which will improve the accuracy of fault description,and lay a foundation for determining favorable areas for complex oil and gas exploration.
作者
胡建波
刘之的
段玉顺
丁富峰
HU Jianbo;LIU Zhidi;DUAN Yushun;DING Fufeng(School of Earth Sciences and Engineering,Xian Shiyou University,Xian,Shaanxi 710065;Shaanxi Key Laboratory of Petroleum Accumulation Geology,Xian Shiyou University,Xian,Shaanxi 710065;Changqing Branch,Geophysical Research Institute,BGP,CNPC,Xian,Shaanxi 710021;PetroChina Changqing Oilfield Company,Xian,Shaanxi 710065)
出处
《地质与勘探》
CAS
CSCD
北大核心
2023年第4期891-900,共10页
Geology and Exploration
基金
陕西省重点研发计划项目(编号:2022GY-130)
西安石油大学研究生创新与实践能力培养计划(编号:YCS22213068)资助。
关键词
小尺度断裂
沿层曲率
地震属性
方位角
频带
small-scale fault
curvature along the layer
seismic property
azimuth
frequency band
