Development of an efficient and practical algorithm for time-to-depth conversion in reflected profile

Time-depth conversion is a critical stage in the geological interpretation of reflection seismic data, as its precision determines the accuracy of structural interpretation at reflective interfaces and geological profile products. The fidelity primarily depends on accurate stratigraphic velocity definition and the conversion method. Conventional velocity modeling for oilfield data heavily relies on logging data, while single-average velocity conversion lacks accuracy in complex lithological formations. Existing technologies struggle to balance between “modeling cost” and “conversion accuracy”. To address this challenge, this paper proposes a novel time-depth conversion strategy at the interpretation-level output stage. This method abandons direct full-time domain resampling. Instead, focusing on the interpreted reflectors, it constructs a layer velocity input interface and employing a layer-by-layer stripping and cumulative thickness algorithms, it achieves refined conversion and output for these layers only, avoiding full dataset processing. Application of this method to interpret actual reflection data from a maritime area significantly reduced the computational complexity of time-depth conversion while enhancing computational efficiency, it also eliminated structural distortions caused by seafloor topographic undulations, effectively improving interpretation accuracy. Practical application demonstrates the method’s utility and efficiency in deepwater environments and complex geological conditions lacking well control, providing a new low-cost, high-precision geological pathway.