You might be able to achieve something if you can somehow freeze your olive oil and chill your dough, and work very quickly during lamination, but you should, even with a lot of work and tweaking, still expect to get a noticeably inferior product for something like croissants.
Depending on how picky you are/not, you might still be personally happy with the texture and taste, but don't expect to get even remotely close to an actual good butter croissant, by more objective standards. Here in Canada we had a minor problem with the butter texture due to what we feed our cows here ("buttergate"), and this was preventing professional bakers from achieving quality croissants with just the Canadian butter. This should make you highly skeptical that you can get anything good with something as different as olive oil.
Still, I do love the idea of an olive oil croissant, it would be delicious.
I am thinking if an ideal butter croissant has some flaky fluffiness (perhaps if we define it as "trapped volume" between flakes), and we define this ideal flakiness to be 100%, then you can extremely easily get to 20% with just olive oil. Frankly I think you might even get close to 50% (defined in this way) provided you also start with a trustworthy recipe by mass and that aims for proper hydration (e.g. https://www.seriouseats.com/croissants-recipe-11863500) and work quickly with lots of chilling.
Just, subjectively, you might realize that 20-50%, defined this way, isn't much like a proper French croissant, and is more like a cheap doughy supermarket chain croissant—which I do still frankly enjoy sometimes anyway!