Hello there! So, basin modelling is a process where scientists and engineers study how rocks, water, and oil move inside the Earth.
You know how when you pour water into a cup, it fills up the cup until it can't hold any more? Well, the Earth also has cups, but they're much bigger and they hold different things, like rocks and oil.
Scientists and engineers study these big cups, which they call basins, to see where oil and gas might be hiding. They use special computer programs to create models, or simulations, of how the rocks and fluids inside these basins move.
This helps them figure out where oil and gas might have come from, how much there might be, and where they might be able to find more.
And that's basically what basin modelling is - studying the big cups inside the Earth to understand where oil and gas might be hidden.