Method Research and Application of Stripping Strong Reflection of Igneous Rock Based on Forward and Inverse

The strong reflection signal of igneous rock has a great shielding effect on its above and below reservoirs, often resulting in poor effect of reservoir prediction. How to strip the strong reflection signal to highlight the effective signal is an urgent problem. Due to the local distribution of igneous rock in the study area, and its thickness changes rapidly, and the reservoir also shows relatively strong reflection, it is easy to suppress effective signals by using wavelet decomposition and reconstruction methods to remove strong reflection. Therefore, the method of stripping strong reflection based on forward and inversion is innovatively proposed. First, the thickness and plane distribution of igneous rock are depicted by spectral inversion. Then, using the appropriate wavelet and the extracted impedance volume of igneous rock, the forward modeling is carried out to obtain its strong reflection signal. Finally, through data fusion, seismic data has been gotten without strong reflection of igneous rock. Model test and practical application show that this method can strip igneous rock strong reflection signal more accurately and reserve effective reservoir signal better. By inversion using the processed seismic data, the superimposed relationship and pinchout point of predicted sandstone are reasonable and clear, which better supports the well location deployment in this area. The formed method of stripping strong reflection based on forward and inversion has certain guiding significance for removing strong reflection of special lithological in similar areas or zones.