Wall Street's top oil watcher says there are three geopolitical headwinds that might be "coming to a head in October" — and they could have implications for oil markets.

The three risks come from uncertainty surrounding Iraq's Kurdish region, the nuclear deal with Iran, and the ongoing crisis in Venezuela, according to RBC Capital Markets' Helima Croft.

Here's an outline of her arguments why those three regions are something oil watchers should keep an eye on:

In short, geopolitical risks look like they might be coming back for some oil producers. And even if they manage to avoid "full-blown crises," Croft argues they will continue to "face considerable turbulence."