Prestack land data multiple removal example

The above methodology has also been tested on a shot record from a land data survey. The preprocessing and multiple prediction is described by (). I display in Figure a the selected shot record. Figure a shows the predicted multiples. Note that these multiples are the ones that are directly generated by the shot record based convolutions () and no adaptation has been applied yet. Both 312#312 and 1#1 adaptive subtraction has been carried out for this data. The resulting records are displayed in Figures b and c, respectively. The removed multiples are shown in Figures b and c.

Figures b and c demonstrate that the multiples are better attenuated with the 1#1-norm for long offsets. Although the truth cannot be revealed from these results, it appears that the 1#1 results are more reliable.

 

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Figure 14 Example of adaptive multiple subtraction for land data. a) One selected shot record from a land survey. b) Estimated signal after 312#312 adaptive subtraction. c) Estimated signal after 1#1 adaptive subtraction.

 

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Figure 15 a) Predicted multiples for Figure a. b) Removed multiples with 312#312 adaptive subtraction. c) Removed multiples with 1#1adaptive subtraction. Far offset multiples are better attenuated with the 1#1-norm between 1.2 and 1.8 seconds.