Quantitative Monitoring for Enhanced Geothermal Systems Using Double-Difference Waveform Inversion with Spatially-Variant Total-Variation Regularization

Conference · Sat Jan 01 04:00:00 EST 2011

OSTI ID:1013592

Lin, Youzuo ^[1]; Huang, Lianjie ^[1]; Zhang, Zhigang ^[1]

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1. Los Alamos National Laboratory

Double-difference waveform inversion is a promising tool for quantitative monitoring for enhanced geothermal systems (EGS). The method uses time-lapse seismic data to jointly inverts for reservoir changes. Due to the ill-posedness of waveform inversion, it is a great challenge to obtain reservoir changes accurately and efficiently, particularly when using timelapse seismic reflection data. To improve reconstruction, we develop a spatially-variant total-variation regularization scheme into double-difference waveform inversion to improve the inversion accuracy and robustness. The new regularization scheme employs different regularization parameters in different regions of the model to obtain an optimal regularization in each area. We compare the results obtained using a spatially-variant parameter with those obtained using a constant regularization parameter. Utilizing a spatially-variant regularization scheme, the target monitoring regions are well reconstructed and the image noise is significantly reduced outside the monitoring regions. Our numerical examples demonstrate that the spatially-variant total-variation regularization scheme provides the flexibility to regularize local regions based on the a priori spatial information without increasing computational costs and the computer memory requirement.

• Research Organization: Los Alamos National Laboratory (LANL)
• Sponsoring Organization: DOE/LANL
• DOE Contract Number: AC52-06NA25396
• OSTI ID: 1013592
• Report Number(s): LA-UR-11-10599
• Country of Publication: United States
• Language: English

Related Subjects

ACCURACY
COMPUTERS
Earth Sciences
FLEXIBILITY
GEOTHERMAL SYSTEMS
Geothermal Energy (15)
MONITORING
REFLECTION
TARGETS
WAVE FORMS