VSP波形反演品质因子方法及应用

提出了利用上、下行波旅行时联合反演地层层速度,并记录波的传播路径及传播时间,然后根据波场传播理论,利用VSP上、下行波波形反演品质因子(Q)的方法.该方法不仅符合波场衰减理论,同时解决了利用单一下行波或上行波反演Q值的算法不稳定、精度不高、信息量不足的问题,得到了稳定、可靠的Q值.数值模拟和实际资料处理结果均表明,文中方法可以有效、稳定地估计Q值,提高地震资料的分辨率,得到主频更高、频带更宽的地震资料,可更加清楚地识别不整合面、小断裂等地质特征及其接触关系,对油气预测和储层反演具有现实意义.

Quality factor estimation with VSP waveform inversion

We propose in this paper a joint inversion approach to invert Q factor. First, interval velocity is inverted with up-going and down-going wave travel time. And then, Q factor can be estimated with up-going and down-going wave waveforms according to the wave filed theory. This approach not only conforms to the wave attenuation theory, but also can be utilized to gain a more stable and reliable Q value than conventional methods with up-going wave or down-going wave alone. Both numerical simulation results and real data examples indicate that the proposed approach can get a higher resolution and wider band seismic data, and help us obtain much clearer unconformity structure, small faults and their relationships. Therefore, it is of great value for reservoir characterization and inversion.