Abstract: The invention relates to DAS observation has been proven to be useful for monitoring hydraulic fracturing operations. While published literature has shown focus on the high-frequency components (>1 Hz) of the data, this invention discloses that much of the usable information may reside in the very low frequency band (0-50 milliHz). Due to the large volume of a DAS dataset, an efficient workflow has been developed to process the data by utilizing the parallel computing and the data storage. The processing approach enhances the signal while decreases the data size by 10000 times, thereby enabling easier consumption by other multi-disciplinary groups for further analysis and interpretation. The polarity changes as seen from the high signal to noise ratio (SNR) low frequency DAS images are currently being utilized for interpretation of completions efficiency monitoring in hydraulically stimulated wells.

Abstract: Method and system for ongoing monitoring for underground structure at or near a production wellpad is provided. The system includes a sparse acquisition grid and utilizes information obtained from Rayleigh waves to monitor subsurface structures.

Abstract: A method of monitoring hydraulic fracturing using DAS sensors in a treatment well and/or observation well is described. The raw data is transformed using a low pass filter (?0.05 Hz) and down-sampled to show the signal as the stimulation progresses. The resulting data can be used to optimize the hydraulic fracturing or improve reservoir models for other reservoirs.

Abstract: The invention relates to DAS observation has been proven to be useful for monitoring hydraulic fracturing operations. While published literature has shown focus on the high-frequency components (>1 Hz) of the data, this invention discloses that much of the usable information may reside in the very low frequency band (0-50 milliHz). Due to the large volume of a DAS dataset, an efficient workflow has been developed to process the data by utilizing the parallel computing and the data storage. The processing approach enhances the signal while decreases the data size by 10000 times, thereby enabling easier consumption by other multi-disciplinary groups for further analysis and interpretation. The polarity changes as seen from the high signal to noise ratio (SNR) low frequency DAS images are currently being utilized for interpretation of completions efficiency monitoring in hydraulically stimulated wells.

Abstract: A method of monitoring hydraulic fracturing using DAS sensors in a treatment well and/or observation well is described. The raw data is transformed using a low pass filter (?0.05 Hz) and down-sampled to show the signal as the stimulation progresses. The resulting data can be used to optimize the hydraulic fracturing or improve reservoir models for other reservoirs.

Abstract: Method and system for ongoing monitoring for underground structure at or near a production wellpad is provided. The system includes a sparse acquisition grid and utilizes information obtained from Rayleigh waves to monitor subsurface structures.

Abstract: Refracted energy travel time can help to derive anisotropic parameters in a target layer. These anisotropic parameters allow us to both explore for new reservoirs and to understand stress and fracturing in existing reservoirs. This information can be used to i) detect oil reservoirs, ii) spot naturally fractured, hence high production zones, iii) detect dominant natural stress directions, iv) better place horizontal wells to optimize production, v) monitoring man made fractures or induced directional stress changes. The method is demonstrated using synthetic and real data.

Abstract: Refracted energy travel time can help to derive anisotropic parameters in a target layer. These anisotropic parameters allow us to both explore for new reservoirs and to understand stress and fracturing in existing reservoirs. This information can be used to i) detect oil reservoirs, ii) spot naturally fractured, hence high production zones, iii) detect dominant natural stress directions, iv) better place horizontal wells to optimize production, v) monitoring man made fractures or induced directional stress changes. The method is demonstrated using synthetic and real data.