True amplitude migration in constant gradient velocity media

• Main Author: Castillo López Luis Antonio
• Format: Article
• Language: English
• Published: Universidad Nacional de Colombia 2003-08-01
• Series: Earth Sciences Research Journal
• Subjects: True amplitude recovery; PSDM; gradient velocity media
• Online Access: http://www.revistas.unal.edu.co/index.php/esrj/article/view/31427

&lt;p class="MsoNormal" style="line-height: normal; margin: 0cm 0cm 0pt; mso-layout-grid-align: none;"&gt;&lt;span style="font-family: ";Arial";,";sans-serif";; font-size: 12pt; mso-ansi-language: EN-US;" lang="EN-US"&gt;The kirchhoff conventional algorithm using ray tracing is based on a constant velocity function. This solution, where is incorporated ray path information into conventional algorithm, can be extended to a variable velocity medium. Velocity models include the locations of reflectors and interval of velocities between any two adjacents reflectors that are generally generated through the velocity analyses, process important in traditional seismic processing. This process could be achieved by applying a weighted diffraction stack operator, which theoretical development is based on a Kirchhoff type migration integral. By choosing the proper weight for stacking the data, the result of the migration process is a seismic section where the amplitude are recovered and its value are proportional to the reflection coefficient, the so-called true-amplitude migration (True Ampiltude Recovering). Migration process was applied into different models. the objetive is to reproduce an accurate picture of the subsurface model from the data registered in areas where the velocity changes. The migration process was obtained after trying several testes made with different weigths.&lt;/span&gt;&lt;/p&gt;<br>&lt;p class="MsoNormal" style="line-height: normal; margin: 0cm 0cm 0pt; mso-layout-grid-align: none;"&gt;&lt;span style="font-family: "&gt;El algoritmo de Kirchhoff con trazado de rayo se basa en una función de velocidad constante. Esta solución incorpora información de trayectoria de rayos dentro del algoritmo, el cual puede extenderse a un medio de velocidad variable. El modelo de velocidad incluye la localización de reflectores e intervalos de velocidades entre dos reflectores adyacentes, generados a través del análisis de velocidad, pero importante en el procesamiento sísmico tradicional. Este proceso puede alcanzarse al aplicar un operador de función peso de apilado por difracción, cuyo desarrollo teórico se basa en la integral de migración tipo Kirchhoff.&lt;/span&gt;&lt;/p&gt;&lt;p class="MsoNormal" style="line-height: normal; margin: 0cm 0cm 0pt; mso-layout-grid-align: none;"&gt;&lt;span style="font-family: "&gt;Al escoger el propio peso para el peso de apilado de datos, el resultado del proceso de migraci6n es una sección sísmica donde se recupera la amplitud y su valor es proporcional al coeficiente de reflexión, llamado migración con amplitudes verdaderas (recuperación de amplitudes verdaderas).&lt;/span&gt;&lt;/p&gt;