Method of raising seismic resolution with micro measuring well perpendicular to seismic profile and double well

Abstract

The method of raising seismic signal resolution with vertical seismic profile and double micro log includes obtaining the transmission functions of seismic signal in different depth of loess tableland in low velocity layer and velocity lowering layer so as to obtain attenuation restoring filter function for restoring the received attenuated seismic signal; and using the attenuation restoring filter functions of different depth or different time to restore the received seismic signal so as to raise seismic signal resolution. The present invention provides lithologic seismic prospecting with powerful tool, and may be used in the seismic signal restoring in the area with ground of low velocity layer and velocity lowering layer.

Description

Technical field: [0001] The invention relates to a method for improving the resolution of seismic signals by using vertical seismic profile (VSP) and seismic double-well micro-logging, in particular, using VSP and double-well micro-logging to observe the attenuation law of signals in low and slow-velocity zones such as loess plateau , and an effective method to improve the seismic signal resolution by compensating the signal in this area. Background technique: [0002] In areas covered by loess plateaus such as the southwest Tarim Basin and the Ordos Basin in my country, although the underground oil and gas resources are very rich, the large difference in thickness of the loess coverage area leads to the problem of surface static correction and the strong absorption of seismic signals by the loess, resulting in a low signal-to-noise ratio. Due to the influence of these reasons, seismic data in such areas are greatly limited in solving geological problems. [0003] The excita...

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Problems solved by technology

"It is proposed to use the micro-logging direct wave signal to calculate the absorption compensation inverse filter of sand layers in desert areas with different thicknesses to compensate the high-frequency components of seismic data; , ordinary geophones can be used, as long as the tail cone of the geophone is inserted into the hard soil, the tight coupling between the geophone and the medium can be ensured, which greatly reduces the energy loss when the geophone receives. However, since the medium in the well is air, in loess The lithology of the medium in the borehole wall in the plateau area is generally loose loess, so the wave impedance of air and loess is very different. When the effective wave is incident on the borehole wall, the reflected wave is very strong, and the transmitted wave is extremely weak. There will be a certain attenuation at the receiver point on the surface, so that the effective wave arriving at the receiver point will be weaker

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