Ahead of the U.S.-Iran nuclear talks on Friday, Tehran signaled that the negotiations will likely be a long process, dashing hopes of a quick and more sustainable de-escalation of tensions in the key oil-producing Middle Eastern regions. Oil prices initially rose early on Friday in Asian trade on the news, with Brent climbing to $68 per barrel and WTI Crude prices trading at $64 a barrel, before both fell back later in the day. Investors and speculators seemed to interpret the signals from Iran to mean the initial round of discussions…