This article, written by Senior Technology Editor Dennis Denney, contains highlights of paper SPE 125085, ’Worldwide Deepwater Petroleum Exploration and Development Prospectivity: Comparative Analysis of Efforts and Outcomes,’ by Omowumi O. Iledare, SPE, Louisiana State University, prepared for the 2009 SPE Annual Technical Conference and Exhibition, New Orleans, 4-7 October. Empirical indicators derived from deepwater-specific data show that the expansion in deepwater operations is a response to global oil demand as onshore petroleum resources deplete. A study showed that the evolution of deepwater development is very pronounced around the three Atlantic basin deepwater zones (Africa, Latin America, and North American Gulf of Mexico). Introduction The empirical indicators were derived from deepwater-specific data obtained from private and public sources, including an online private database purchased from Infield Oil Field Systems, information collected over time at the Center for Energy Studies, and public data from the US Department of the Interior online database of the Minerals Management Service. Here, deepwater operations are defined as Slope, water-depth range between 200 and 400 m; Deep, water-depth range of 400 to 1500 m; and Ultradeep, water depth greater than 1500 m. Operating firms are classified as an international oil company (IOC), a national oil company (NOC), or a local/independent oil company (LOC). Worldwide, deepwater petroleum basins were classified into five regions—Africa, Latin America, North America, Europe, and other (Asia, Australasia, Middle East, and the Caspian). The study period was 1983–2007. Factors Affecting Deepwater Operations Petroleum pricing encourages companies to search for and develop petroleum resources, including the more difficult areas such as the deep offshore. Technology progress in geological-information gathering and processing has made exploration and production operations more efficient. Advances in exploration, drilling, completion, and production technologies have made the search for and development of petroleum more cost effective and environmentally responsible. Frontier areas considered uneconomical and too difficult a few decades ago have become prime targets for petroleum exploration and development as a result of improved imaging technologies, including 3D-seismic and time-lapse systems. Open access to petroleum resources in deep water is wider in the three Atlantic basin deepwater zones—Africa, Latin America, and the Gulf of Mexico. Currently, most deepwater operations and activity are concentrated in Africa, Latin America, and the US Gulf of Mexico. Global Appraisal Attributes of worldwide deepwater prospectivity include fields discovered, fields on stream, discovery-to-production lag, field-depletion life, operational wells, wells under development, and future wells. Well completions have either subsea or surface wellheads.