Near surface attenuation compensation using downhole seismic data in the Qianjiang New Town area in urban Hangzhou

The development of geophysical methods has increased the relevance of seismic surveys on near-surface geological structures in urban areas. In recent years, one important issue faced by many scholars is how to effectively increase the signal-to-noise ratio of seismic signals and improve the resolution of seismic information. Near-surface layers typically exhibit low velocity and severe lateral velocity variation characteristics due to weathering. Loose structures in a near-surface condition caused by weathering indicate low quality factor, resulting in the intensive absorption of seismic waves passing through these layers, which ultimately limits the effectiveness of information acquired from the received spectrum. To facilitate the investigation of geological conditions such as bedrock surface undulations and hidden structural faults underground in the Second Stage of Qianjiang New Town, Hangzhou City, an analysis of shallow surface attenuation compensation based on downhole seismic data is conducted. In addition, based on the downhole seismic data, the quality factor Q of underground strata was obtained using a spectral ratio method, and the inverse Q filtering was applied to a stacked seismic reflection section in Hangzhou. A set of shallow surface absorption and attenuation compensation techniques suitable for the Second Stage of Qianjiang New Town, Hangzhou City is developed, which can effectively improve the resolution and detection accuracy of seismic sections and provide reliable seismic data and reference methods for future exploration and development in this area.

Automated summary

The development of geophysical methods has enhanced the relevance of seismic surveys in urban areas. To address issues related to signal-to-noise ratio and resolution of seismic signals, researchers have conducted shallow surface attenuation compensation analysis based on downhole seismic data, and applied inverse Q filtering techniques to improve the resolution and accuracy of seismic sections.