The land seismic data used in this paper is from South America. In CMPX-CMPY coordinate, the CMPX range of seismic data is approximately from 1.65km to 5.8km and CMPY is approximately from 0.375km to 7.925km.
There are about 30 wells drilled in this area. Some of them are productive, some are moderately productive and one is dry. Most of the wells have spontoneous-potential, resistivity, gamma ray and sonic logs. Some wells have density and neutron logs.
Figure 1 shows the well locations in this area. The straight line is where we will extract seismic amplitude information. The line was chosen by matching the wells A, B and C using linear least square method, resulting in coordinate as cross-line=106.33 (CMPY=2.225km). Table 1 is the detailed information of the coordinates of three wells used to match the line.
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wellloc
Figure 1 The well locations and the 2-D line along which we performed velocity analysis. |  |
| 5cTable 1: The coordinates of the wells | ||||
|---|---|---|---|---|
| Well | Inline | Crossline | CMPX | CMPY |
| Well A | 501 | 104 | 3.875km | 2.125km |
| Well B | 422 | 109 | 5.375km | 2.375km |
| Well C | 473 | 106 | 4.575km | 2.225km |
The wells don't lie exactly along the line. The cross-line distance between the line and the well A, B and C are 100m, 150m and 0 respectively. We assume the rock properties don't change rapidly across these small spans.