Imaging processing method and device for Ordovician fracture-cave system

Abstract

The invention discloses an imaging processing method and device for an Ordovician fracture-cave system. The imaging processing method comprises the following steps of: acquiring, to be specific, acquiring a root-mean-square velocity function; converting, to be specific, converting the root-mean-square velocity function by utilizing a constraint velocity inversion method to acquire an interval velocity body; migrating, to be specific, performing prestack time migration to target seismic data to obtain migrated target seismic data; picking up, to be specific, performing automatic pickup residual velocity processing according to the migrated target seismic data to obtain a residual velocity; updating, to be specific, updating the interval velocity body according to the residual velocity body; repeatedly executing migrating, pickup processing and updating until the seismic data acquired in the migration processing step is in accordance with the requirement of geological laws so as to obtain a final interval velocity body; and performing prestack time migration processing to the whole seismic data according to the final interval velocity body. According to the imaging processing method and device for the Ordovician fracture-cave system, the imaging effect of prestack time migration can be improved, and the imaging is finer.

Description

technical field [0001] The invention relates to the technical field of oil and gas exploration, and more specifically relates to an imaging processing method and device for an Ordovician fracture-cavity system. Background technique [0002] As a key field of Paleozoic carbonate oil and gas exploration, the quality of Ordovician carbonate rock and its seismic exploration data in the Tazhong area is different from other areas, and its particularity is mainly reflected in: ① lithofacies and lithology ②The scale of fractures and caves is generally small, and the karst development is poorer than that of the Tazhong uplift; ③The signal-to-noise ratio of seismic data in desert areas is low, and it is difficult to image the fracture-cave system in the inner Ordovician. [0003] In the Ordovician fracture-vuggy reservoir imaging technology, a more important step that affects the imaging effect is the pre-stack time migration method. The velocity used in the prestack time migration m...

AI Technical Summary

Problems solved by technology

[0004] The root mean square velocity model is based on the horizontal layered medium, and its derivation is limited by certain assumptions, and the derivation formula is simplified and omitted, which cannot accurately reflect the properties of the horizontal layered medium

For complex geological environments, such as the geological conditions in the Tazhong area, the t-rms-vel velocity model may not change much, resulting in an inaccurate t-rms-vel velocity model, which in turn affects the imaging effect of pre-stack time migration, and ultimately affects Accurate identification of Ordovician fractured-vuggy bodies

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