Driven by a rush to add oil reserves that can be tapped in the future, most of these deals are expected to wrap up this year and will unleash a burst of oil wells, pipelines, offshore fields and infrastructure packages onto the market. The lack of ready buyers suggests sales will take time and may turn into asset swaps, rather than cash sales. Three acquirers - Chevron (NYSE: CVX ), ConocoPhillips (NYSE: COP ) and Occidental Petroleum (NYSE: OXY ) - have pledged to raise between $16 billion and $23 billion combined from post-closing sales.