Dear Benjamin,
The input data that you have is a 2D Line ( a prestack data). So, you have to make a 2D survey project setup and once the project is launched and the data is imported, you can select on 2D line in the tree and display it.
For creating a 2D project correctly,
Step 1: Note down the X and Y coordinate range if you have. If you do not have it, then you can obtain it from your Pre-Stack data, by scanning your data through Opendtect.
Step 2: Then once you got these information, click on " setup new project", then go for "manually selecting for 2D". Enter the X coordinate and Y coordinate ranges and assign the grid spacing.
Step 3: Once this is done a a survey box will be created with fake inline and crosslines.
Step 4: Then Import your seismic data
Step 5: Once the import is successful, click on 2D line in the left side within the tree and then display your data.
Hope this helps you !
With kind Regards
Chinmoy