General Chirplet Extracting Transform and Its Application in Reservoir Stratigraphic Interpretation

Accurately characterizing complex and unconventional reservoirs is crucial for improving oil and gas recovery efficiency and reducing exploration and development risks. It is feasible to precisely interpret stratigraphic information using time-frequency (TF) characteristics derived from seismic signals. We have developed a general chirplet extracting transform (GCET) for stratigraphic interpretation of reservoirs. First, two instantaneous frequency (IF) equations are constructed within the general chirplet domain. From these equations, two distinct extracting operators are derived: one designed for harmonic-like features and the other for impulse-like features. Each operator selectively extracts TF coefficients that satisfy its corresponding IF equation. Additionally, an adaptive fusion strategy is introduced, which utilizes local sparsity measures to combine the extracting results, thereby enabling the dynamic construction of the GCET. The proposed GCET method simultaneously generates TF representations for both harmonic and transient modes, effectively characterizing the TF features of seismic signals with superior noise resistance. Tests on both synthetic and field seismic data demonstrate the efficacy of the proposed method for reservoir stratigraphic interpretation.