Research on the Identification of Sandstone Vanishing Points Based on Synchronous Compression Matching Pursuit Method

Abstract

The portrayal of sand cusp extinction is the key to evaluating the effectiveness of tectonic-lithological composite confinement, and it is difficult to accurately identify the location of sand cusp extinction due to the influence of seismic data band limitations. In order to effectively solve the problem of inaccurate identification of cusp extinction on seismic sections, this paper innovatively introduces the dual advantages of time-frequency resolution and energy focusing of synchronous compression match tracing to carry out the sand-cusp extinction identification research. Firstly, the time-frequency domain pleated-product operator is used to construct the redundancy dictionary of match tracing with the constraints of the initial model, and all the possible matching atoms are screened out to form the alternative atom bank in the time-frequency domain. The initial model constraints and the time-frequency domain joint inversion method are introduced into the inversion framework, which can obtain more accurate inversion results. Then, the dominant frequencies are extracted by channel-by-channel analysis using the simultaneous compressive match-tracking transform, and the time-frequency transient spectra are screened to obtain the single-frequency spectral profile with the optimal frequencies. The two-dimensional model and actual data testing of the proposed method show that the high-resolution seismic spectral decomposition sand-cusp identification method based on synchronous compression and matching tracking can obtain richer time-frequency domain information and get the single-frequency spectral profile with the optimal frequency, thus accurately identifying the location of cusps of subsurface geological bodies, which is of great significance for the depiction of cusps of overburden-type and erosion-type lithological confinement.

Keywords

• seismic inversion
• synchronous compression
• matching pursuit
• time-frequency analysis
• vanishing point identification