V2C is a software system using for building velocity field research and structure mapping, designed for earthquake interpreter, which is completed after 10 years of continuously innovation and development during western oilfield velocity related research in China. The system commendably solves problems of velocity field building and mapping in condition of complicated surface, complicated structure and complicated lithological character area; integrates four velocity mapping methods: master curve method, average velocity method, horizon control method and model chromatography.

Key technologies

1）Data Conversion

2）Data Preprocessing

3）2D Gridding

4）3D Gridding

5）Trend Smoothing

6）Database Data Query

7）Seismic Velocity Analysis

8）Well Velocity Analysis

9）Velocity Correction

10）Migration T Reversed Map Migration

11）Ray Tracing Migration

12）Profile T-Depth Conversion

13）Velocity Field Building

14）Error Correction

15）Integrative velocity splicing

16）Velocity Field Integrated Application

The overthrust belt speed field model

3D Gridding

Ray Tracing Migration

Accurate and varied velocity field building methods：

Master Curve Method：

Advantages: Taking full advantage of well data and seismic model and consideration of overthrust model;

Range of Application: Structural mapping of areas with no velocity spectrum or incredible velocity spectrum;

Average Velocity Method ：

Advantages: High mapping efficiency and 3D velocity trend smoothing’s ability to remove abnormal velocity values in a certain degree;

Range of Application: Structural mapping of areas with simple surface and subsurface condition or extensive areas;

Horizon Control Method：

Advantages: Consideration of the lateral continuous variation of interval velocity and field building under the restriction of well data based on interval velocity smoothing;

Range of Application: Solution for variable velocity mapping of areas with good stratification and small dips;

Model Chromatography Method：

Advantages: 3D migration and good solution for high spot migration of steeply dipping formation;

Range of application: Piedmont high steep structure with quality velocity spectrum;

Different method will be applied in accordance with the geological condition and data quality.

The examples of low-amplitude structures migration and Steeply-dipping structures migration.