Oil and gas pools are found in numerous sedimentary basins, which occur throughout the world. Estimates indicate that nearly 30% of Earth's basins currently produce hydrocarbons, nearly 40% are moderately explored but have not yielded large amounts of production, and the remaining 30%-plus are essentially unexplored. Certainly, abundant oil and gas accumulations still await the drillbit. These will be teased from the ground by the application of both innovative prospecting concepts and the wonders of today's technologies. Advanced seismic methods, extended-reach and horizontal wells, sophisticated logging suites, and fresh completion strategies will all aid the hunt. Still, as eminent explorationist Wallace Pratt famously observed, oil is found in the minds of men (and these days, of women as well). During the past decade, international exploration shifted strongly toward deepwater provinces and also toward natural gas. Much of the success in deep water to date has been in basins rimming the Atlantic Ocean. The deepwater Gulf of Mexico, West Africa and Brazil plays all feature mature source rocks, excellent reservoirs and abundant structures, and will continue to be fertile grounds for prospectors. Operators, emboldened by their successes in these challenging yet very rewarding areas, are pushing into unexplored or lightly explored offshore basins. Also of keen interest are the Arctic regions of the world. And, deeper sediments beneath established fields in well-known producing areas will receive closer scrutiny. Finally, unconventional resources will be a focus for many companies in the more mature regions of the world, particularly in the U.S. Deepwater hot spots In recent years, major oil operators have scored discovery after discovery in the prolific deep waters offshore West Africa. The region stretching from Nigeria to Angola will continue to dominate the world's deepwater exploration. The intense interest in offshore West Africa is due to the high success rate for exploratory wells, the very large size of the discoveries, and the relatively benign operating environment. The accumulations here are Tertiary turbidite sands that occur in a wide variety of structural traps. Successes in the established areas are encouraging prospectors to look at basins all along Africa's Atlantic coast, from Morocco to Mauritania to South Africa. Africa's Mediterranean region is also gaining attention, thanks to good results in Egypt's deepwater Nile Delta, where Tertiary reservoirs have been found in structural, stratigraphic and combination traps. The Gulf of Mexico is the other top spot for deepwater exploration, and this vibrant play will continue to be very active. As in West Africa, operators report discovery after discovery, although the Gulf of Mexico finds are not generally as large. Still, the stable political regime, attractive fiscal terms and developing infrastructure make the area highly desirable to majors and independents alike. A wave of exploration in the Eastern Gulf's Lloyd Ridge and DeSoto Canyon areas is now under way, and blocks offered in the federal offshore lease sale this month will be eagerly snapped up. The Minerals Management Service notes that it has received 20 exploration plans for leases in the area and that BP's Kings Peak project, in 6,600 feet of water in Desoto Canyon 133, is already producing. Mexico is rapidly becoming one of the world's bright stars for exploration, particularly as Pemex pushes into the deeper waters of the unexplored Mexican Gulf. Large structures have been identified on seismic, and parallels to the prolific deepwater fields in the U.S. Gulf are irresistible. Brazil will be another busy area in deepwater exploration, although successes have not been as frequent as international companies hoped when they entered the arena. Indeed, Petrobras has scored most of the significant finds in the past few years in the Campos and Santos basins. Nonetheless, a number of international operators are facing lease expiration deadlines on their offshore blocks in 2004, and need to drill obligation wells. Also look for an uptick in exploration in previously undrilled basins along South America's Atlantic margin. India is coming on strongly as a deepwater province as well. Recent multi-trillion-cubic-foot (Tcf) gas finds have been made in the Krishna-Godavari Basin off the country's western coast, sparking widespread interest in this new play. Indonesia and Malaysia have also both enjoyed recent deepwater success, gaining both gas and oil discoveries. Unocal has been very successful in the Makassar Straits and Kutei Basin, offshore eastern Kalimantan. Murphy Oil Corp.'s Kikeh discovery offshore Sabah contains between 400 and 700 million barrels of oil, one of the largest finds made in the world in 2002. Traditional offshore basins While the deepwater wildcats grab headlines with impressive flow rates and hefty reserves, a great deal of bread-and-butter exploration will proceed around the globe, targeting smaller accumulations in shallower-water basins. Independents are responding enthusiastically to the U.K. government's efforts to encourage new companies to enter the North Sea. A fresh group of operators is bringing capital and ideas to those mature environs, where the tremendous in-place infrastructure can make even small finds economic. Their efforts will center on seeking deeper reservoirs and satellite accumulations near existing fields. Upcoming work in Norway's North Sea sector will also feature the same sorts of close-in exploration. And, drilling will continue on the Norwegian continental shelf. Natural gas exploration has been gaining prominence in Norway, particularly in light of the European Union's growing gas demand, and both the Norwegian Sea and the Barents Sea are prone to gas. Canada's east coast, particularly the Scotian Shelf offshore Nova Scotia, will also enjoy a healthy level of exploration. Several wildcats are currently under way or planned in both shallow and deep waters. Targets range from traditional structural closures in the Sable sub-basin to carbonate reservoirs in the Jurassic to salt-related domes and features in the deepwater salt province. In the U.S. Gulf of Mexico, the deep shelf play is still vibrant. Here, geologists search for basin-floor fans and sand sheets that are sealed by shale caps. The reservoirs are overpressured and compartmentalized, and successful wells yield excellent production rates. According to the Minerals Management Service, the deep shelf holds potential for between 5- and 20 Tcf of gas reserves. And, in the shallow waters of the Mexican Gulf, Pemex plans to continue its light-oil and gas exploration in the Veracruz and Tampico-Misantla basins. Arctic regions Interest is high once again in the world's Arctic basins, and the coming year should see additional exploration. In Canada, a number of companies are ramping up activity in the Mackenzie Delta-Beaufort Sea area, in anticipation of the completion of the Mackenzie Valley pipeline. Exploration interest is growing in the Yukon Territory also, in such areas as the Eagle Plain Basin. There are numerous sedimentary basins in the Northwest Territories and Yukon Territory that are prospective and that will likely see seismic acquisition and drilling in the coming years. Russia's major potential also lies along its northern continental shelves, in the Barents, the Kara, the Chukchi, the East Siberian seas and the Sea of Okhotsk. Already, extremely large accumulations have been identified in some of these areas, and many more prospects remain to be drilled. Russia's Natural Resources Ministry recently announced plans, pending government approval, to offer licenses on 22 high-potential blocks on its Arctic shelf. Onshore activity The Middle East, North Africa, Mexico, Venezuela and Argentina will have active onshore programs in 2004. Overall activity in the Middle East will be brisk, but most drilling will be directed at raising productive capacity in existing fields. Exploration is relatively stalled in the region, as countries are offering terms that don't particularly attract international explorers. The national oil companies, however, are continuing to look for non-associated gas plays and reservoirs in deeper Paleozoic sediments beneath existing fields. Iran is believed to have tremendous untapped potential, particularly in heavier crudes and in its portion of the Caspian Sea. Indeed, the entire Caspian Sea remains a high-interest area for the world's oil community. Russia looms large in the exploration outlook. The vast country has many active plays, from established areas in Western Siberia to lightly explored Arctic regions. Onshore, exploration will continue in the Timan-Pechora and Volga-Ural provinces. In Mexico, the multiple-service contracts recently awarded by Pemex in the Burgos Basin will spur exploration on those blocks. At press time, Repsol YPF and a joint venture of Petrobras and Teikoku had taken the first two of the Burgos blocks. Venezuelan activity is picking up after the disastrous national strike, and drilling is expected to be brisk in the Maracaibo and East Venezuela basins. South America's Andean basins also hold many prospects for gas discoveries. Look for the Southern Cone's Neuquen, Magallanes and San Jorge basins to be thick with prospectors. Petrobras plans to invest $1.4 billion in Argentina during the next five years. There remains considerable potential in many parts of onshore Africa, and such countries as Algeria, Libya and Egypt will host a steady stream of wildcats. The northern and southern portions of the continent are beginning to develop their gas resources as well. China has been aggressively explored during the past few years, and its national oil firms and foreign participants have scored some notable successes. Upper Tertiary structural traps have been prolific producers in the Bohai Sea, Upper Paleozoic accumulations have been found in the Erdos Basin, and Mesozoic anticlines and faulted closures have been found in the Tarim Basin. More good news should flow from China as it keeps up its drilling pace. Finally, several plays will enjoy continued exploration within the relatively mature Western Canada Sedimentary Basin. The foothills fold-and-thrust-belt play, which stretches from Fort Liard into parts of the Yukon and southeast through British Columbia and Alberta to the U.S. border, has considerable gas potential. Operators continue to look for Ladyfern look-alikes in the Devonian Slave Point play in northeastern British Columbia and northwestern Alberta, and the Deep Basin play is stretching from Alberta across the provincial border into British Columbia. Unconventional prospecting is under way as well. Coalbed-methane (CBM) exploration is in its infancy in Canada, but interest is growing steadily. The country is blessed with extensive coal deposits, occurring in many different settings. Look for pilot programs to sprout up throughout Canada, especially in Alberta, British Columbia and Nova Scotia. U.S. onshore exploration In the U.S., upcoming exploration efforts will concentrate on finding conventional reservoirs that are deeper, tighter, higher-pressured and hotter than in years past. Unconventional sources will be a prime focus, with companies looking to develop new basin-center, CBM, tight-gas and fractured-shale plays. In the northeastern U.S., explorationists will continue to work the Ordovician Trenton-Black River play throughout a broad trend stretching from central New York to West Virginia. They will hunt areas of fault-controlled hydrothermal dolomites, which produce in structural lows that can be identified on seismic. Success in the Trenton-Black River is also leading to a reevaluation of many of the Paleozoic carbonates throughout the Appalachian Basin, and explorers are looking at diverse units such as the Stones River and Nashville groups in Tennessee and southern Kentucky. And, inspired by present gas prices and the success of the Barnett Shale play in North Texas, explorers will investigate the potential of fractured shales throughout the region. In the Illinois Basin, exploration efforts will be centered on attempts to expand CBM production from its current base in Indiana's Vigo and Sullivan counties. Also expect some activity directed at prospecting in the Geneva Dolomite, which is productive where it is draped over Silurian pinnacle reefs. A recent high-rate horizontal well discovery in Marion County, Illinois, has sparked regional interest in the Geneva play. The Midcontinent will see a mixture of shallow exploration for CBM accumulations and a deep campaign, driven primarily by Chesapeake Energy Corp. That firm has acquired more than 3,500 square miles of 3-D seismic data, mainly in the Anadarko Basin. It has an extremely active drilling program, and is pursuing Paleozoic targets up to 25,000 feet deep. Throughout the Forest City, Cherokee and Arkoma basins, operators will attempt to establish and expand CBM production. Coals in these basins are generally thin, and can be undersaturated with gas, so establishing commercial production has been challenging in some areas. There has been excellent success in the Arkoma Basin with horizontal drilling in the Hartshorne coal, and this approach has generated widespread interest. In the southeastern U.S., Alabama operators will continue to look for Miocene sandstone reservoirs, which occur in a wedge that thickens dramatically from Baldwin County to the coast. Bright-spot technology works well in this play. And, 3-D seismic will be used to hunt for reefs in the Jurassic Smackover in the southwestern part of the state. Florida may also receive some renewed attention in its Sunniland play, which extends both onshore and offshore the southern portion of the state. This trend produces oil from mound buildups. Mississippi will be an area of interest for explorationists. Here, the Jurassic Smackover formation is being probed for both eolian sandstones, as in Tchula Lake Field in the central part of the state, and for reef and mound buildups. In the southern part of the state, a Miocene gas reservoir recently discovered at Mariner Field in southern Hancock County has generated considerable buzz. In the Black Warrior Basin, prospectors are looking for deep gas in Ordovician carbonates, primed by the recent redevelopment of Maben Field in Oktibbeha County, Mississippi. Additionally, operators are investigating the potential of the Cretaceous Tuscaloosa Shale in the southwestern part of the state, and the James Lime in the southern counties. The onshore portion of the deep Jurassic Norphlet play, which extends into state waters offshore, is still relatively unexplored. In Louisiana, interest will circle around shallow Miocene reservoirs in the area north of Lake Pontchartrain and east of the Mississippi River. CBM potential in the Lower Wilcox is also being investigated in the central part of the state. All along the Texas and Louisiana Gulf Coast, independents will persist in hunting for Oligocene Hackberry, Frio and Vicksburg and Eocene Yegua and Wilcox targets. Seismic data is crucial for these plays, which can feature bright spots or amplitude-versus-offset anomalies. South Texas will feature a steady stream of deep gas tests. Too, a deep Jurassic test that is currently drilling in the Maverick Basin of Texas is being closely watched; if successful, look for a surge of interest in like prospects in the surrounding area. Additionally, unconventional resources will garner attention in Texas. The fractured Barnett Shale play has been extremely active, and exploration is moving steadily outward from the core Barnett area north of Fort Worth. And, Pennsylvanian and Permian coals are of interest as potential CBM reservoirs in such foreland basins in Texas as the Kerr, Val Verde Marathon and Marfa. The Rocky Mountain region is widely hailed as an up-and-coming supply powerhouse for the nation, thanks to its abundance of unconventional resources. The Green River Basin in Wyoming alone has some 160 Tcf of tight gas sand resources and 300 Tcf of CBM resources. Other basins such as the Wind River and Big Horn are lightly explored, particularly in their deeper portions. In the Piceance and Uinta basins, large tracts of land offsetting existing production are still undrilled because they lie on federal lands with restricted access. Expect carbonaceous shales to receive some attention in the Rocky Mountain basins in the coming year. There are thick sequences of these shales in nearly every basin, but to date only the Lewis Shale in the San Juan Basin has been exploited to any degree. California exploration activity will likely be limited, with operators drilling some deeper-pool tests in the San Joaquin Basin, and continuing to prospect for small gas pools in the complex Sacramento Basin. Last, but not least, Alaska will be interesting on several fronts. Conventional gas exploration and CBM pilots are under way in the Cook Inlet region. On the North Slope, additional drilling is expected in and around the National Petroleum Reserve-Alaska. The foothills of the Brooks Range may begin to see drilling activity as well. The future of exploration All the easy oil and gas has been found. What's left for today's explorers are the deposits in unforgiving environments, in unbelievably deep reservoirs and in astounding water depths. There also exists a tremendous resource base of low-grade deposits, which require a new set of exploration skills. As technology stubbornly pushes back the boundaries of economic deposits, opportunities continually present themselves to alert and far-sighted prospectors.