Accession Number:

ADA327291

Title:

Migration Velocity Analysis.

Descriptive Note:

Interim rept. Jan-Mar 95,

Corporate Author:

COLORADO SCHOOL OF MINES GOLDEN CENTER FOR WAVE PHENOMENA

Personal Author(s):

• Liu, Zhenyue

Report Date:

1995-03-01

Pagination or Media Count:

97.0

Abstract:

This thesis addresses the development of a general, quantitative representation between the imaged depths and migration velocity. Based on ray theory, I have found that the migration process can be described by using the so-called imaging equations. From this viewpoint, I have studied relationships between the residual moveout and the error of migration velocity in a general context. To handle lateral velocity variations, I used a perturbation method to derive an analytical formula to iteratively update the velocity from residual moveout. My formula estimates the update in velocity by computing a derivative function of imaged depths with respect to velocity in a general background medium context. This formula is more accurate than conventional formulas based on hyperbolic residual moveout when the medium has strongly lateral velocity variations. In addition, I discuss the sensitivity of migration-based velocity analysis, and show what factors affect the sensitivity. The theory and formulas developed here are available both for the 2-D case and for the 3-D case. The methodology in this thesis have been tested on synthetic data including the Marmousi data and on physical-tank data that are recorded in a scaled earth model.

Descriptors:

• *MIGRATION
• VELOCITY
• THESES
• IMAGES
• DIFFERENTIAL EQUATIONS
• PERTURBATIONS
• EARTH MODELS
• COMPUTERIZED TOMOGRAPHY

Subject Categories:

• Numerical Mathematics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE