摘要
为了准确利用横波分裂方法探测裂缝,将天然地震资料处理常用的双扫描算法应用到转换波勘探,有必要对其适用条件和反演精度进行研究。从横波分裂基本性质出发,首先归纳了双扫描算法的流程;然后以含裂缝地层模型为例,测试了切向能量法、旋转相关法和协方差矩阵法三种双扫描算法在不同条件下的反演精度和鲁棒性;最后将其应用到西部M工区致密含气砂岩储层的裂缝探测,并与传统能量比值法进行了对比。结果表明:1当炮检方位与裂缝发育方位间隔一定角度时,三种双扫描算法都能得到准确结果;2与另外两种方法相比,切向能量法更加稳定,可以应用到炮检方位接近裂缝发育方位的特殊情况;3炮检距对双扫描算法存在一定影响,炮检距增大时误差也随之增大。
Shear-wave splitting (SWS) plays a key role in fracture detection.Recently,the splitting inversion methods of dual-scanning type,which have been merely used in deep geophysical prospecting,now are used in converted wave for oil and gas reservoir detection.In this paper,we firstly summarize the processing flow of dual-scanning methods,then test the performance of three dual-scanning (transverse energy,rotation correlation,and covariance matrix) with different azimuths and different offsets in a fracture model.Finally we apply these three methods to a tight sandstone gas reservoir exploration in West China,and compare inversion parameters with those calculated by energy ratio method.Based on our work,the following conclusions are obtained: 1.All the three dual-scanning methods show a reliable performance when the radial direction keeps away from fracture azimuth; 2.The transverse energy method is the most reliable method among these three,which can work well even the radial direction closes to fracture azimuth; 3.The inversion precision of dual-scanning methods can be affected by offsets. © 2017, Editorial Department OIL GEOPHYSICAL PROSPECTING. All right reserved.
出处
《石油地球物理勘探》
EI
CSCD
北大核心
2017年第1期105-113,共9页
Oil Geophysical Prospecting
基金
中国石油天然气集团公司科学研究与技术开发项目"弹性波地震成像技术合作研发与应用"
国家杰出青年科学基金项目(41425017)联合资助
关键词
横波分裂
裂缝探测
双扫描
致密含气砂岩
Covariance matrix
Fracture
Geophysical prospecting
Oil well testing
Petroleum reservoir engineering
Petroleum reservoirs
Sandstone
Scanning
Shear flow
Slow wave structures
Tight gas
