An Integrated Calibration Method of Fault-Seal Capacity in Sand-Clay Sequences: Mechanisms, Principles, and Potential Pitfalls

Fault seal failure envelops calibrated by researchers can hardly be interpreted by the variation mechanisms of fault-rock permeability. We attempt to introduce an integrated calibration method of fault-seal capacity from rock deformation mechanisms and their controls on fault permeability and discuss the potential pitfalls in its application. Fisrtly, the sealing capacity of faults have a lower and upper bound which are controlled by cataclasis density and properties of low permeability host rocks. Secondly, periods of fault activation and main stage of oil accumulation should be clarified before calibration to identify whether hydrocarbon reservoirs are damaged by trap-bounding faults, in order to avoid overestimating the sealing capacity of reactivated trap-bounding faults. Then, AFPD-SGR data from faults reactivated after the main stage of oil accumulation can be never used in the calibration of SFE, which may cause the underestimation of sealing capacity of stable trap-bounding faults. Finally, the integrated calibration of SFE from previous compatible work could help not only to identify a potential reactivated fault on the geological time scale and also to understand the sealing capacity or permeability on the production time scale.