Saudi Aramco will begin shale and unconventional gas exploration and drilling in 2013 with seven gas exploration wells in the Red Sea—unconventional shale-gas estimates for Saudi Arabia exceed 600 trillion cubic feet. The country’s oil minister did not address commercial unconventional resource production or how it will supply enough water for fracturing. The largest identified deposit is in the Qusaiba Paleozoic reservoir in the Rub Al-Khali (The Empty Quarter).

Over the last year, shale-oil production from the U.S. has cut into Saudi Arabia’s oil production lead. U.S. crude production in November and December topped 7 million barrels a day for the first time in 20 years. Saudi output in December was 9.6 million barrels per day and November output was 9.2 million barrels per day.

The International Energy Agency has predicted the U.S. will overtake Saudi Arabia as the world’s largest oil producer by 2020.

The kingdom has a modest gas output (10 billion cubic feet per day), and so far it hasn’t increased gas production enough to replace oil as feedstock in planned petrochemical or electricity-generating projects.

According to an Aramco executive, “Oil capacity is not the question, it is whether we need to spend billions maintaining it at all.”

—Larry Prado

1. Argentina

Shell Oil Co. reported a hydrocarbon discovery in Argentina’s Vaca Muerta play. The horizontal discovery is in the Sierras Blancas de Vaca Muerta in Neuquen Province. After unspecified fracturing, the well produced 465 bbl. per day of light crude. Additional discovery and completion information is not available. O&G Developments is the operator of the Sierras Blancas Block and discovery well with 65% interest in the Union Transitoria de Empresas Sierras Blancas joint venture with Medanito and Gas y Petroleo del Neuquen, which hold 25% and 10% interests respectively. Shell is based in Houston.

2. Argentina

A study funded by Calgary-based Madalena Ventures Inc. has concluded the company’s unconventional shale resources on its three Neuquen Basin blocks (Coiron Amargo, Curamhuele, and Cortadera) in Argentina have an estimated 34.8 billion bbl. of oil equivalent. The 2012 review focused on Vaca Muerta shale, Lower Agrio shale, and Basal Quintuco and was based on data from 19 delineation and discovery wells on the blocks, with 2-D or 3-D seismic coverage, and core analysis. According to the study, the best case P50 total petroleum initially in place was 34.8 billion bbl. of oil equivalent (51% crude oil and natural gas liquids (NGLs), plus prospective recoverable resources of 2.9 billion bbl. of oil equivalent (45% crude oil and NGLs).

3. Norway

Stavanger-based Statoil completed appraisal well #16/2-17 S in the Johan Sverdrup extension in Block PL 265 to determine reservoir properties and thickness near the main western boundary fault. The well hit an 82-meter Upper Jurassic gross oil column and showed high quality oil in a 38-meter thick interval. The well also proved good reservoir qualities in Middle/Lower Jurassic, with some thin shaley intervals. One drillstem test produced 420 standard cu. meters of oil per day when tested on a 40/64-in. choke from a seven meter Middle/Lower Jurassic sandstone interval. A second test, gauged on a 48/64-in. choke, flowed 920 standard cu. meters of oil per day from the 38-meter interval in Upper Jurassic. An 800-meter sidetrack to the west at #16/2-17 B is now planned to explore the oil potential on the basement high immediately west of Johan Sverdrup. Statoil is the operator of PL265, Block 16/2, and the Johan Sverdrup Field with 40% interest in partnership with Petoro (30%), Det Norske Oljeselskap (20%) and Lundin Norway (10%).

4. Cote d’Ivoire

At Cote d’Ivoire’s Gulf of Guinea Block CI-100, Paris-based Total announced an oil discovery at #1X-Ivoire. The well is in 2,280 meters of water. It was drilled to 5,044 meters and hit 28 meters of net oil pay in a series of about 100 meters of Cretaceous reservoirs. This is the first well drilled on the CI-100 Block and it confirms the extension into Block CI-100 of the petroleum system in the Tano Basin. An appraisal program for the reservoirs is planned to identified prospects further east in the block near recent discoveries in Ghana. Block operator Total holds a 60% interest, with Yam’s Petroleum, 25% and Petroci Holding, 15%.

5. Equatorial Guinea

An oil discovery was announced by Noble Energy Inc. at exploration well #1-I at the Carla South prospect in offshore Equatorial Guinea. The well hit oil in good quality sandstones at the target level and it will be sidetracked to an adjacent target. Drilled to 3,660 meters, analysis indicates that the deviated well penetrated approximately 12 meters of net oil pay. Additional information is not available. After logging is complete, the well will be sidetracked. Houston-based Noble owns 38% interest in the well, with Atlas Petroleum International (27.55%), Glencore Exploration (23.75%), and PA Resources’ Osborne Resources (5.7%). GEPetrol, the Republic of Equatorial Guinea’s national oil company, has a 5% carried interest.

6. Egypt

Houston-based Apache Corp. an nounced oil and gas discoveries at North Ras Qattara and in the Siwa Concessions in Egypt’s Western Desert. An Alamein Basin discovery, #1X NRQ 3151 in the North Ras Qattara Concession, produced 1,625 bbl. of oil and 18.7 million cu. ft. of gas per day from two intervals in Jurassic Lower Safa. Logging confirmed 100 ft. of pay sands in multiple zones, including Cretaceous Upper Bahariya, Jurassic Zahra, Upper Safa, and Lower Safa. Appraisal drilling is planned in 2013. Apache owns 70% in this North Ras Qattara Concession with IPR holding the remaining 30%. In the Siwa Concession in Faghur Basin, #1X SIWA L flowed 2,041 bbl. of oil per day from the lower-most portion of a Paleozoic Desouky pay sand. The discovery well encountered 123 ft. of hydrocarbon pay in Cretaceous Alam el Buieb (AEB-3E), AEB-5, Jurassic Safa, and Desouky zones. Apache is the operator and has a 50% working interest in the Siwa Concession with the state-owned Tharwa Petroleum Co. also holding a 50% working interest. In the Matruh Basin in North Tarek Concession, #1XBTRK- G hit 60 net ft. of Upper Safa hydrocarbon pay and produced 14.8 million cu. ft. of gas and 1,522 bbl. of condensate per day. Apache has a 100% working interest in the North Tarek Concession.

7. Yemen

A new oil discovery was announced by Calvalley Petroleum at its Ras Nowmah South exploration well in Yemen’s Block 9 concession—based on drilling and petrophysical data, the well encountered 15 meters of gross oil pay (10.5 meters net) with 25% porosity in Qishn. The 1,520-meter well has a downhole pump installed and was placed on production at a restricted rate of approximately 250 bbl. of 19-degree- gravity crude oil per day. Additional clean up is planned. The company plans to drill an appraisal well at Ras Nowmah North to establish the pool’s size. Calgary-based Calvalley is the operator of the Masila Basin block and the Ras Nowmah South and North with 50% interest in partnership with Reliance Industries (25%) and Hood Oil (25%).

8. Australia

Houston-based Chevron Corp. reported that offshore well #1-Elfin hit approximately 132 ft. of net gas pay in the Exmouth Plateau area of the Carnarvon Basin offshore Western Australia. The discovery is in the WA-268-P permit area and production is from the upper Mungaroo sands. The well was drilled to 11,900 ft. in 3,570 ft. of water. Chevron Australia is the operator of WA-268-P with a 50% interest in partnership with Shell Development Australia and Mobil Australia Resources each holding a 25% interest.

9. Australia

According to Senex Energy, the Brisbane-based company has identified up to 2.9 trillion cu. ft. of prospective resource in a conventional stratigraphic reservoir, including 141 billion cu. ft. of 1C contingent resource, at a new gas field (Hornet) in the Cooper Basin. Production logging data from #1-Kingston Rule and #1- Hornet wells confirm a conventional, tight-gas reservoir at approximately 2,500 meters in the Mettika Embayment. During testing, the wells flowed up to 2.2 million cu. ft. per day. The gas accumulation is defined within a stratigraphic trap that extends north, south and east from PEL 115 Hornet Block into Senex’s 100% owned PEL 516. Survey data indicates the gas accumulation intersected by these wells has reservoir characteristics similar to many existing Patchawarra conventional fields. An appraisal program by Senex is planned to confirm the extent of Hornet Field. Operator Senex owns 80% of the discovery and partner Orca Energy owns 20%.

10. Australia

At a gas discovery in VIC/P47, offshore Victoria, a Bass Strait Oil Co. review of potential gas resources at #1-Judith indicated the field could hold a best estimate gross unrisked contingent resource of 101 billion cu. ft. of gas with a high-side estimate of 276 billion cu. ft. of gas. The #1-Judith discovery was drilled in 1989 but was not production- tested or appraised. In 2008 it had a reported gross gas column of 290 meters that was interpreted from electric log data, while its petrophysical analysis indicated 135.5 meters of net gas pay in the well. Melbourne-based Bass Strait has a 40% operating stake in VIC/P47, Moby Oil & Gas owns 35% and Strategic Energy Resources owns 25%.