Seismic analysis of fault damage zones in the northern Tarim Basin (NW China): Implications for growth of ultra-deep fractured reservoirs

Understanding fault damage zone is of significant importance for the characterization and modeling of ultra-deep (greater than 6000 m) fractured reservoirs. However, seismic detection of fracture networks in deep fault zone it is still challenging. For this contribution, we propose a seismic Tensor Thickness Method for optimal imaging of the ultra- strike-slip fault damage zones in the Tarim Basin. The results show reasonable distinction through seismic methods of boundary of fault damage zones in carbonate host rock that is consistent with the fractured reservoirs constrained from borehole data. In addition, this study suggests that fault damage zones in ultra deep settings exhibit width ranging 100-800 m, with a linear correlation between fault damage zone width and throw. Isolated fault zones are characterized with linear relationship between the width and displacement of the strikeslip fault zones, but the abnormally wide fault damage zone is likely attributed to fault interaction and overlapping. The results of this work are applicable for fractured reservoir characterization in deep and tight carbonate rocks elsewhere.

Automated summary

Understanding fault damage zones is crucial for modeling ultra-deep fractured reservoirs, but seismic detection of fracture networks in such zones remains challenging. In this study, a seismic Tensor Thickness Method is proposed for imaging ultra-strike-slip fault damage zones in the Tarim Basin. The results show that seismic methods can accurately distinguish the boundary of fault damage zones in carbonate rock, consistent with borehole data. The study also reveals a linear correlation between fault damage zone width and throw, suggesting the influence of fault interaction and overlapping in abnormally wide zones. The findings have implications for fractured reservoir characterization in deep carbonate rocks elsewhere.