As oil prices entered a second steep slide a few weeks ago, bullish traders and analysts had hoped for a repeat of the sharp but short dip that occurred early in the year – a speculative slide below $50 a barrel followed by a quick recovery. Some are now reconsidering that view, as long-term oil prices take the lead in the market’s latest dive, swaying sentiment toward a lengthier slump that would mean prolonged pain for big producers, from Exxon Mobil Corp (XOM.N) to Saudi Arabia.