Q estimation of seismic reflection data and its application in oil and gas exploration

Abstract

In oil and gas seismic exploration, when the seismic wave propagates in the earth medium, it will encounter obvious absorption and attenuation, resulting in the main frequency of the seismic signal shifting to the low-frequency end. The frequency band narrows and the phase is distorted, which restricts the resolution of seismic exploration to identify thin layers. To obtain a seismic image with higher resolution, this paper introduces a method with effective Q estimation in the imaging domain of seismic reflection data and uses the estimated Q-value to compensate for the attenuation effect through migration to achieve high-resolution imaging. This method introduces the concept of effective Q-value into the time domain. In the time window of the initial viscoelastic time migration image, the effective Q parameters in the time domain are determined through the compensation effect of the data in the time window. Then, the time-depth conversion function is obtained by calculating the imaging ray in the layer velocity in the depth domain, and then the time-depth conversion is carried out for the Q parameters converted to the layer Q-value in the time domain. At last, the key parameter is used as the input of viscoelastic prestack depth migration for viscoelastic compensation imaging of complex structures. Finally, this paper uses the real seismic data from eastern China to verify the effectiveness of the method. The final results show that the process and method developed in this paper can better realize the Q-value modeling and imaging domain compensation in the depth domain, and realize the high-resolution imaging of complex structures.

Keywords

• viscoelastic media
• q
• attenuation compensation
• time-depth conversion
• high resolution imaging