Angular response compensation for DAS VSP

A method for processing DAS VSP surveys to perform amplitude correction in real-time or offline, the method comprising:

• activating a seismic source of energy or listening to a seismic source of energy by a distributed acoustic sensing (DAS) data collection system coupled to at least one optical fiber at least partially positioned within a wellbore;
• sending an acquired seismic dataset from the DAS data collection system to an information processing system communicatively coupled to the DAS data collection system, the seismic dataset comprising a plurality of seismic data records that are each associated with a different activation of the source by the DAS data collection system to produce a seismic signal;
• sending a slowness profile as a function of measured depth within the wellbore from the DAS data collection system or from a VSP processing system to an information processing system;
• converting, by the information processing system, the seismic dataset into intercept-time ray-parameter domain dataset;
• determining, by the information processing system, local apparent slope for each seismic signal in the received seismic dataset;
• performing, by the information processing system, amplitude correction for the received seismic signals by using the slowness profile and the determined local apparent slope in the intercept-time ray-parameter domain dataset;
• and
• converting, by the information processing system, the corrected intercept-time ray-parameter domain dataset into the spatiotemporal domain.

An information processing system communicatively coupled to a distributed acoustic sensing (DAS) data collection system, the information processing system comprising a processor and a memory device coupled to the processor, the memory device containing a set of instruction that, when executed by the processor, cause the processor to:

• receive an acquired seismic dataset from the DAS data collection system, the seismic dataset comprising a plurality of seismic data records that are each associated with a different activation time of a source or with a different listen time of a source by the DAS data collection system to produce a seismic signal;
• receive slowness profile as a function of measured depth within the wellbore from the DAS data collection system or from a VSP processing system;
• convert the seismic dataset into intercept-time ray-parameter domain dataset;
• determine local apparent slope for each seismic signal in the received seismic dataset;
• perform amplitude correction for the received seismic signals by using the slowness profile and the determined local apparent slope in the intercept-time ray-parameter domain dataset;
• and
• convert the corrected intercept-time ray-parameter domain dataset into the spatiotemporal domain.