频率域多尺度断裂检测技术在长宁页岩气勘探中的应用

Application of frequency domain multi-scale fault detection technique in shale gas exploration in Changning region

陈珂磷 井翠 杨扬 任晓莉 王利田

四川长宁天然气开发有限责任公司，四川 成都 610056 北京凯利东方石油科技有限公司，北京 100190

Sichuan Changning Natural Gas Development Co., Ltd., Chengdu 610056, China Beijing Carrie Oriental Petroleum Technology Co., Ltd., Beijing 100190, China

四川页岩气勘探开发区块大多位于多期多组构造挤压作用叠加与联合的复向斜单元，构造起伏较大、断层和裂缝非常发育，常规的断裂预测技术无法兼顾不同级别的断裂系统预测。地震资料的不同频带可以反映不同的地质现象和裂缝信息，低频体主要描述大断裂的信息，高频体突出反映受大断裂控制的小断裂的信息，因此，文中从频率域出发，利用频率域多尺度断裂检测技术与叠后常规地震断裂属性，对工区不同尺度断裂体系综合进行精细描述。频率域多尺度断裂检测技术成功将约束最小二乘法频谱分解和不同频率域多种不连续性属性检测等2种技术结合起来，使不同分辨率的地震记录通过不同尺度的不连续属性对比，可以在突出大断裂的同时显示小断裂信息，提高了解释精度，使不同层次裂缝发育情况都能清晰展示出来。

Most of the shale gas exploration and development blocks in Sichuan are laid in the synclinal synclinorium units which are superimposed and united by multi-stage and multi-group tectonic compression, which have the large structural relief and well-developed faults and fractures, so the conventional prediction techniques can not meet the needs of different levels of faults and fractures. Different frequency bands of seismic data can reflect different geological phenomena and fracture information, the low frequency parts mainly describe the information of faults in large scale, while the high frequency parts mainly reflect the information of small faults controlled by large faults. Therefore, based on frequency domain, this paper uses the frequency domain multi-scale fault detection technique and post-stack conventional seismic fault attributes to finely describe the fault development of different scales. The multi-scale fault detection technique in frequency domain combines the constrained least-squares spectral decomposition and discontinuities detection technique in different frequency domains. By comparing the discontinuities of different scales, the seismic signals of different resolution can highlight large scale faults and show the information of small scale faults, which improves the accuracy of interpretation and makes the development of faults and fractures in all levels displayed clearly.

10.6056/dkyqt202203001