Effective seismic imaging technology in igneous rock coverage area and its application to oil and gas investigation in Jinyang Basin of western Liaoning

The Jinyang Basin of western Liaoning is the largest Mesozoic basin of the outer Lower Liaohe Basin. The shallow igneous rocks with great thickness and many periods are widely developed in the basin. The original data of seismic exploration has a low signal-to-noise ratio due to influencing of igneous rocks on seismic signal shielding and complex seismic geological conditions in the area. Meanwhile the reflected energy of the underlying strata of the igneous rock is weak, which brings about great challenges for effective imaging of seismic data. Based on the characteristics of the original seismic data, targeted acquisition and processing techniques were used to improve the deep reflection energy and signal-to-noise ratio of the data by low frequency geophone, static correction, pre-stack multi-domain denoising, reflected energy compensation and so on. The pre-stack time migration technique is optimized for final imaging through comparison by multiple high precision velocity modeling and seismic migration imaging techniques. Compared with the previous seismic data, the signal-to-noise ratio and resolution of the seismic section reprocessed by this effective imaging technology are significantly improved, the deep reflection energy is effectively restored, and the underlying strata of the igneous rock have clear reflection signals and clear contact between the strata. In particular, the imaging of the faults and strata with large dipping angle has been significantly improved in resolution, which provides high-quality seismic data for subsequent structural interpretation and exploration potential area evaluation.