利用Q值各向异性识别裂缝走向  

Fracture orientation detection using Q anisotropy

作　　者：尹志恒[1,2] 魏建新[1,2] 狄帮让[1,2] 李向阳[1,2] 孙文博[1] 齐宇[1] 

机构地区：[1]中国石油大学(北京)油气资源与探测国家重点实验室,北京昌平102249 [2]中国石油大学(北京)CNPC物探重点实验室,北京昌平102249

出　　处：《石油地球物理勘探》2011年第3期429-433,500+328,共5页Oil Geophysical Prospecting

基　　金：国家"973"计划项目(2006CB202306)资助

摘　　要：本文利用地震物理模型方法研究定向排列的裂缝对模型Q值的影响,并找出Q值与地震裂缝走向的关系。物理模型由三层组成,第一层为环氧树脂层,第三层为混合材料,是各向同性介质层;第二层为胶木层,模拟定向排列的垂直裂缝层,是HTI介质层。将物理模型置于水槽中,使用脉冲测量的方法得到物理模拟的三条不同方向测线的二维地面地震数据。对提取的叠前CDP道集数据,使用基于经典的频谱比方法提出的QVO(品质因子Q值随炮检距变化)方法来计算模型目的层位的品质因子。实验结果表明,垂直裂缝层的品质因子Q值随方位角的变化而变化,其中Q最大值方向平行于裂缝走向,最小值方向垂直于裂缝走向,据此可推断裂缝的走向。Using a seismic physical model,we study impact of aligned fractures on Q values of the model,and identify the relationship between fracture orientations and Q value changes.The physical model consists of three layers.The first layer is made of epoxy resin,and the third layer is made of mixed material.Both of them are isotropic layers.The second layer is a bakelite layer,simulating HTI media with aligned vertical fracture.2D data of three lines from different directions were acquired using the pulse-transmission method with the physical model submerged in a water tank.The pre-stack CDP gathers have been used to calculate Q of target zone by the method QVO(Q versus offset) based on the classical spectral ratio theory.According to the experiment analysis,Q of vertical fractured layer changes versus azimuth,where the biggest of Q value appears in the direction parallel to the fracture orientation and the smallest in the normal direction to the fracture orientation.This would be helpful for the fracture orientation detection.

关 键 词：HTI介质 频谱比方法 品质因子 各向异性 裂缝探测 

分 类 号：P631[天文地球—地质矿产勘探]