Automated Three‐Dimensional Reflection Traveltime Modelling to Extract 3D Dipping Layer Geometries

ABSTRACT Steep geological structures are critical for improved understanding of tectonic processes and fluid circulation, particularly in crystalline settings. However, accurately determining their geometry at depth remains a challenge for conventional 2D surveys. In this study, we present an automated three‐dimensional (3D) reflection traveltime modelling approach to estimate 3D subsurface geometries of dipping reflectors. The method utilises the traveltime hyperboloid equation adapted for dipping reflected events. The required inputs include the acquisition geometry, the known location where the dipping layer intersects or projects to the surface, pre‐stack gathers, first‐break picks and reflection hyperbola picks. The traveltime equation is modified and adapted to incorporate common available information from seismic acquisitions, and the resulting function is analysed to optimise the input parameters. The study also highlights the sinusoidal behaviour of the objective function and demonstrates the importance of multi‐azimuth acquisitions in constraining the possible reflector geometries. The output consists of a root mean square (RMS) error map for all modelled dip–strike pairs relative to the picked reflection traveltime, the best‐fitting reflector geometry and its corresponding modelled reflection traveltime. If desired, the best‐fitting reflector can also be modelled in the migrated stacked section for comparison purposes. Compared to traditional manual techniques, the proposed method improves accuracy, reduces the operator dependency and provides quantitative reliability metrics. Owing to its simplicity and application efficiency, this method can be largely applied in onshore reflection seismic data interpretations, where 2D crooked profiles commonly provide multi‐azimuth coverage, enabling improved delineation of steep structures such as faults and dykes.