Method for jointly suppressing multiple waves of shallow-sea OBC seismic data

Abstract

The invention discloses a method for jointly suppressing the multiple waves of shallow-sea OBC seismic data. The method comprises the following steps of S1, recording seismic waves by means of a pressure detector and a velocity detector simultaneously in the submarine cable acquisition mode, and carrying out water and land consolidation; S2, removing multiple waves through the combination of a plurality of methods for suppressing multiple waves in the topographical and staged manner.

Description

technical field [0001] The invention relates to the field of seismic technology, in particular to a method for jointly suppressing multiple waves of shallow sea OBC seismic data. Background technique [0002] In terms of geological structure, the basement of a basin is composed of Mesozoic and Paleozoic carbonate rocks and metamorphic rocks, and the overlying strata are composed of Paleogene, Neogene and Quaternary clastic rocks. There is a big difference in the wave impedance characteristics between the two, and the strong reflection interface similar to this situation also includes the sea surface and the bottom of the sea. In addition, the seabed in the exploration area is shallow, and the water depth is generally less than 50m, which is relatively flat, so that most of the energy is confined between the sea surface and the seabed, and propagates back and forth, resulting in the development of multiple waves in the original seismic data, with various types, such as strong...

AI Technical Summary

Problems solved by technology

In order to implement the new oil and gas exploration objectives and data requirements in the sag, the seismic exploration work used the three-dimensional and four-component acquisition method of the submarine cable (OBC) for seismic data acquisition. Compared with conventional streamer acquisition, this acquisition method can theoretically obtain Richer elastic information, the obtained original data includes four components of X, Y, Z, and P, of which the X, Y components record the converted wave, and the Z, P components receive and record the longitudinal wave through the vertical velocity detector and the piezoelectric detector respectively , here we mainly discuss the multiple wave problem of the longitudinal wave component. The difference from conventional streamer acquisition is that this acquisition method can obtain two types of longitudinal wave data with different attributes at the same location. There are significant differences in other aspects, therefore, compared with the conventional longitudinal wave treatment, there are similarities and differences, and it is necessary to carry out targeted treatment according to its characteristics

Moreover, the multiple waves in the exploration area have two notable features: they almost cover up the energy of the effective waves; the shallow sea water causes the multiple waves to mix with the effective waves, which cannot be effectively distinguished

In addition, the underwater multiples coupled to reservoir imaging, and the multiples generated by complex structures with the same velocity as deep primary waves, etc., all seriously affect the correct identification of effective waves and affect AVO reflection. Drilling and Reservoir Prediction Results

Images