Application of Residual Structure Analysis Technique in Low Amplitude Structure Mapping

Low-amplitude structure refers to a kind of geological body with relatively gentle structure and low closure amplitude. Generally, the structure amplitude is about 10 m. The low-amplitude structure in seismic profile shows that the reflection event is straight and the variation amplitude is small, which is not easy to identify. Due to the impact of structure setting on the plane, it is difficult for conventional mapping methods to display low-amplitude structural features, which is not conducive to the identification of oil and gas sweet spots. The residual structure analysis technique can decompose the trend and local details of the plane data of structure travel time, which can highlight the low-amplitude structure features. In this paper, two methods of residual structure analysis are developed, namely, trend decomposition method and wavelet transform method. The two methods weaken the influence of regional structure from different angles, eliminate the interference of different regional backgrounds on low-amplitude structure, highlight local detail changes, and make the shape of low-amplitude structure more accurate and clearer. The application of the two techniques in the slope zone of the Oriente Basin has significantly improved the identification accuracy and evaluation efficiency of low-amplitude structures in the study area, and the rapid deployment of multiple horizontal wells has achieved good results.