Method for combining near-surface velocity model with middle-deep stratum velocity model

A technology of velocity model and fusion method, applied in the field of seismic exploration data data processing

Active Publication Date: 2015-04-29
CHINA PETROLEUM & CHEM CORP +1
View PDF4 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

There is no literature related to this aspect of work

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for combining near-surface velocity model with middle-deep stratum velocity model
  • Method for combining near-surface velocity model with middle-deep stratum velocity model
  • Method for combining near-surface velocity model with middle-deep stratum velocity model

Examples

Experimental program
Comparison scheme
Effect test

Embodiment approach 1

[0132] (1) Calculate the optimal velocity analysis datum elevation

[0133] According to the near-surface velocity model of each shot point and receiving point of CMP and the parameters of the observation system, the elevation of the reference plane for velocity analysis optimized by CMP is calculated. Firstly, use formula (1) to calculate the optimal velocity analysis datum elevation at the shot point and receiving point, and the offset distance is 2000m, and the sum of the thickness of the underlying high-speed formation and the thickness of the low-velocity zone is also taken as 2000m. The sum of the thickness of the underlying high-speed formation and the thickness of the near-surface velocity model is equal to the offset. The offset and the thickness of the underlying high-velocity formation have some influence but are not sensitive to the calculated preferred velocity analysis datum elevation.

[0134] Calculate the average value of the preferred velocity analysis datum...

Embodiment approach 2

[0146] (1) Calculate the optimal velocity analysis datum elevation

[0147] The method of calculating the preferred velocity analysis datum elevation of the CMP point is the same as that of Embodiment 1, and the preferred velocity analysis datum elevation of the CMP is -109m.

[0148] (2) Obtain the velocity function representing the medium-deep velocity model

[0149] In the second way, the velocity function in Table 2 obtained from the velocity analysis relative to the final datum plane is corrected. Formula (3) calculates the round-trip travel difference △t from the final datum to the preferred speed analysis datum 0 =-87.2ms. Using equations (4) and (5) to calculate the velocity function of the relatively preferred velocity analysis datum is shown in Table 9 (the velocity function obtained from the final datum velocity analysis is adjusted to the preferred velocity analysis datum (elevation-109m)). Directly use the Dix formula to convert to the depth domain, and obtain ...

Embodiment approach 3

[0159] (1) Calculate the optimal velocity analysis datum elevation

[0160] The method of calculating the elevation of the preferred velocity analysis datum level of the CMP point is the same as that of Embodiment 1, and the preferred velocity analysis datum level of the CMP is at the elevation -109m.

[0161] (2) Obtain the velocity function representing the medium-deep velocity model

[0162] In the third way, the velocity function in Table 2 obtained from the velocity analysis relative to the final reference plane is corrected by fitting the hyperbolic reflection time-distance curve. First determine the offset range, take the same offset as the model data, from 0m to 1520m, and the track spacing is 40m. Secondly, according to the two-way travel time and speed in the speed function of Table 2 obtained from the speed analysis relative to the final datum, the hyperbolic equation Calculate the time-distance relationship of each reflection layer; the third is to apply the sta...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a method for combining a near-surface velocity model with a middle-deep stratum velocity model, and belongs to the field of seismic exploration data processing. The method comprises the following steps: (1) the near-surface velocity model, an observation system, a velocity analysis reference surface and speed functions or seismic data obtained through velocity analysis are input; (2) a preferable velocity analysis reference surface of a CMP (common midpoint) is calculated according to the near-surface velocity model and the observation system; (3) velocity analysis is conducted relative to the preferable velocity analysis reference surface obtained in the steps (2) to obtain a velocity function representing the middle-deep stratum velocity model, or a speed function obtained through velocity analysis relative to a non-preferable velocity analysis reference surface is corrected according to the difference of the velocity analysis reference surface and the preferable velocity speed analysis reference surface to obtain the velocity function representing the middle-deep stratum velocity model; (4) the near-surface velocity model is combined with the middle-deep stratum velocity model.

Description

technical field [0001] The invention belongs to the field of data processing of seismic exploration data, and in particular relates to a fusion method of a near-surface velocity model and a middle-deep velocity model to establish a velocity model from the surface to the deep. Background technique [0002] Establishing a velocity model from the surface to the depth is required for prestack depth migration. Due to the limitations of technical conditions and available data, it is still impossible to directly obtain the entire velocity model from the surface to the depth from seismic exploration data. [0003] Complex near-surface velocity models have a significant impact on wavefield propagation. Correspondingly, whether the near-surface velocity model is considered in the velocity model and the accuracy of the near-surface velocity model have a significant impact on the migration imaging results. With an accurate velocity model from the surface to the deep, existing prestack...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01V1/30
Inventor 林伯香袁联生徐颖朱海波
Owner CHINA PETROLEUM & CHEM CORP
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap