I wonder about the state of their infrastructure & would assume it will take some time for them to ratchet up production assuming an agreement is reached.  Additionally, does Iran have LNG facilities?

Eoin Treacy's view

Thank you for this question which may be of interest to the Collective. First off let’s break the potential for exports down into the oil and gas. When the sanctions were relaxed in 2015, Iranian oil exports jumped by 1.5 million barrels a day within 12 months. Exports have dwindled since sanctions were reimposed and currently sit at only 290,000 barrels. In the event sanctions are again relaxed, it is reasonable to expect at least an additional million barrels of supply within a short period of time.
Iran does not have LNG export facilities, but it has the 2nd largest gas reserves in the world. Any exports in the short term would rely on a daisy chain of pipelines. The construction of a pipeline to Azerbaijan is nearing completion and a tripartite agreement has been signed to allow flow of gas between Iran, Turkmenistan and Azerbaijan. Several pipelines have been planned over the years, particularly through Turkey to Europe, but none have bene completed because of the sanctions regime. The lengthy pipeline to Pakistan has been completed on the Iranian side but not the Pakistani side for the same reason.

The allure of significant revenue will inevitably be weighed against geopolitical considerations. Afterall, Iran is a strategic partner of Russia’s so slow rolling exports may be a solution. Here is a section from an article in Middle East Eye:

“The Russians will not easily allow Iran to enter the European gas market and will use all their means to prevent Europe from losing its gas dependence on Russia,” the journalist told MEE on condition of anonymity. 

“While the current government is controlled by conservatives, some hardliners may oppose any idea and plan by the state to export gas to Europe," he said. "They will probably argue that Iran shouldn’t save the US and Europe from a crisis.”
European natural gas prices continue to set new highs so they are likely to be amenable to whatever deal Iran wishes to secure supply of both oil and gas.