基于束波变换的叠后缝洞精细成像处理技术

碳酸盐岩储层中溶蚀孔洞和断裂的精确成像是地震油气勘探和开发的关键。以塔里木盆地塔河油田某区块奥陶系碳酸盐岩缝洞型储层为例,在精细的叠前预处理和逆时偏移的基础之上,利用束波变换技术,对研究区的地震数据进行了不同尺度的分解和重构,并对处理结果进行了对比分析。结果表明:束波变换技术可以有效改善溶蚀孔洞和断裂的成像效果,小尺度的束波变换适用于溶蚀孔洞信息的提取,而大尺度的束波变换更有利于增强断裂的清晰度,实际应用中应根据地质体的大小来选择合理的尺度参数。

A Processing Technology of Post-stack Seismic Data of Cave and Fracture Based on Beamlet Transform for Fine Imaging

Fine Imaging of corroded caves and fractures in carbonate reservoirs is the key to exploration and development of oil and gas. Taking the fractured-cavity carbonate reservoir of Ordovician in an area of Tahe Oil-field of Tarim basin as an example, the beamlet transform was used to decomposing and rebuilding the seismic data of the target area, and the processing result was compared with each other, which was based on the fine pre-stack processing and RTM(reverse time migration). The results show that the beamlet transform could improve the imaging effect of corroded caves and fractures effectually. On the other hand, the beamlet transform of small scale is suit for signal extract of corroded caves, and the beamlet transform of large scale is good for increasing clarity of fractures. In the practice, the value of scale should be decided by the size of geologic body.