Upvote:2
They will almost certainly ask you questions about the conference, because you say that is the reason you're travelling. They'll probably want to know why you're going and what you intend to do there. Are you giving a presentation? If so, what is it about?
Just tell them the truth and be confident. Remember that you know much more about the conference than they do: they're visa officers, not software developers or experts in the oil and gas industry. Because it's an oil and gas conference, they might ask you questions about oil and gas. It shouldn't matter if you don't know the answers, as long as you can explain why you don't know. And you can explain that: you're a software developer, not an expert on oil and gas.
It's probably not a good idea to try to memorize answers to questions ahead of time. That will make it look like you've been told what to say, which makes it look like you're not telling the truth.