In recent years, the oil and gas sector has focused heavily on exploration in frontier regions, seeking new opportunities in areas previously underexplored. However, given the competitive landscape, opportunities in more mature areas have also captured the industry’s interest, often viewed as lower risk for exploration due to existing infrastructure and an existing breadth of knowledge.
There are understandably some strong tensions between the appetite for risk and perhaps the opportunity to be part of a big find in frontier basins. Some companies are taking a more cautious, but perhaps not necessarily less expensive, approach to exploration in mature basins. Whichever route is favored, pressures on budgets mean that potentially not all good exploration ideas can be followed through.
In the future, how can oil companies better identify the best exploration opportunities? Basing these decisions on better data, which in turn is based on sound acquisition and processing, is a start. Applying interpretative techniques such as lithology prediction and leveraging geological and geophysical (G&G) knowledge and experience to delineate prospects effectively are good subsequent steps.
It is core to PGS’ strategy to tackle these challenges head on. We developed our unique dual-sensor cable acquisition technology, GeoStreamer, in order to reduce the risks inherent in poor and band-limited seismic data. We have now deployed GeoStreamer across most of our fleet of acquisition vessels, including the recently launched Ramform Titan-class vessels, each of which can tow up to 24 streamers. We use GeoStreamer extensively for both proprietary client surveys as well as for building our multi-client data library, meaning that recorded data will be richer in frequency content, ultimately enabling better geological modelling and improved prospect definition and identification.
We employ in-house G&G staff, our Reservoir department. Their focus is on setting our direction towards the most prospective places globally to acquire new multi-client data. Additionally, clients are requested for input on the early stages of multi-client survey design, the best processing flow to adopt, and also to better understand what they believe are the most interesting exploration areas of the future.
So, where should the industry explore next? Every expert will have his or her own opinion, but in this article, I’ll talk about a few of the most promising areas: the eastern Mediterranean, Africa, North America, Brazil, the Arctic, Southeast Asia, and northwest Europe.
Greece is set to become a hot prospect in 2014 exploration plans; the Greek Ministry of Environment, Energy & Climate Change will be launching an offshore licensing round mid-year, with more than 200,000sq km of acreage to be made available. PGS has played an instrumental role in providing seismic data over areas to be included in the licensing round, thus enabling companies to properly evaluate opportunities. Greece offers political stability and an EU transparent framework for hydrocarbon exploration. Offshore, Greece has working petroleum systems in place with several promising plays, analogues to discoveries in adjacent countries, and good frontier potential in unexplored basins.
PGS has also been an official data provider for the First Offshore Licensing Round in Lebanon, which is scheduled to close in 2014, with block awards thereafter. Our extensive 3D and 2D data coverage shows prospective plays and potential analogues to the recent major gas discoveries in the vicinity, and the potentially more oil-prone Levant Margin. Currently, the Ministry of Energy and Water has estimated that Lebanon’s territorial waters may have up to 96Tcf of gas reserves and 850MMbbl of oil.
Cyprus also presents opportunities in 2014, after its second license round closed in 2013, in which several blocks were awarded. In October 2013, Noble Energy indicated that it foresees the potential for 150MMcfd well rates offshore Cyprus in the Aphrodite field. Currently, proven reserves are estimated at about 4Tcf of natural gas, and there is also potential for oil.
Sonangol will be leading an onshore licensing round in Angola in 2014 – the onshore oil blocks on offer are in the terrestrial areas of the Kwanza basin (Blocks KON 3, 5, 6, 7, 8, 9, and 17) and Lower Congo basin (Blocks CON 1, CON 5, and KON 6). These onshore areas cover approximately 50,000sq km, with large parts only minimally explored thus far; earlier onshore exploration phases have resulted in the discovery of 23 oilfields and two small gas accumulations. The Kwanza and Congo basins are examples of the classic passive margin basins on the West African margin which developed as a result of the rifting of Gondwanaland during the Mesozoic, and subsequent separation of the South American and African continents. Areas have been identified where there are thick pre-salt sedimentary depocenters and adjacent structural highs which could contain potential reservoirs, trapped under the Aptian salt.Consequently, onshore Angola is set to be a very interesting prospect for exploration in 2014.
The Congo Republic recently announced that it plans to award 10 onshore and offshore oil blocks, by early next year, in a new licensing round. A series of recent discoveries has meant that interest in the area has been growing again and fresh exploration is expected. In August 2013, Eni Congo SA announced that two recent discovery wells have proven resources of 600MMbbl of oil and 700Bcf of gas in place. In September 2013, CNOOC and Oryx made an oil discovery and spudded a second exploratory well on the Haute Mer A license offshore Congo (Brazzaville). The second well, targeting the Elephant (formerly Xiang) prospect, is expected to be tested in early 2014.
In late October 2013, Gabon moved to award 13 oil and gas blocks in an effort to double its production output 43 blocks altogether have been made available. Earlier this year, Total made a discovery in the deepwater pre-salt area offshore, which has led to a renewed interest in the area. As a result, many international players have become involved through the recent licensing round, with 11 companies assigned blocks.
South Africa represents another very interesting opportunity. Several international oil companies have taken stakes in offshore blocks. Recent interest has moved from the west and south of the country to the eastern offshore area, likely chasing the southward extension of plays that have been identified further north in East Africa, where upstream investment will increase substantially over the next few years. Wood Mackenzie has forecast that investment in East Africa will hit $7 billion annually by 2018.
First, a frontier province: East Canada. The area offshore Newfoundland and Labrador represents strong untapped potential with an estimated 6 billion bbl of oil and 60Tcf of natural gas yet to be discovered. To date, there have been only 20 deepwater wells drilled off Newfoundland and Labrador. The east coast basins alone cover an area bigger than the Gulf of Mexico and are largely unexplored. Initial interpretation of recently acquired 2D data in the Labrador Sea has led to the discovery of three new basins in this untested, deepwater fron- tier. Recent drilling successes, such as Statoil’s Bay du Nord discovery, north of the oil producing Jean D’Arc basin, con- firm strong potential this opportunity alone is assessed at 300-600MMbbl of recoverable oil. Statoil’s earlier discover- ies in the Flemish Pass— Harpoon and Mizzen— help to further reinforce the prospectivity of this area.
Next, the Gulf of Mexico. Yes, it’s a mature petroleum province, but there’s still huge potential here. In the past few seasons and in the coming year, we continue to deploy leading-edge approaches to acquisition. We are adapting technology and survey designs to overcome the challenges of conducting seismic surveys over targets obscured by salt structures. Improving subsalt imaging fidelity will help reduce exploration risk as oil companies explore ever deeper. There has been success here in 2013, with several discoveries, including Anadarko announcing in mid-June that it made a major new discovery in the deepwater Shenandoah play, after Chevron announced a discovery at the Coronado prospect in May. The Gulf of Mexico continues to represent an important part of oil company portfolios, and as technological advances continue, new opportunities will be revealed.
Brazil has been an exciting destination for exploration for many years, where we have acquired substantial volumes of multi-client data to assist oil companies in their exploration. Our Brazil Mega Survey in the Santos and Campos basins is an extremely large regional combination of PGS and ANP/ BDEP open-file 2D and 3D surveys that have been re-gridded onto a common azimuth and amplitude and phase matched. This yielded an improved and consistent regional geological and structural perspective, aided by integrating well information. This has helped identify subtle prospects, play fairways, and migration paths within a regional framework. We started acquiring GeoStreamer data in Brazil in 2009 and more recent surveys have thrown up some exciting potential over, and adjacent to the pre-salt hydrocarbon trend.
Discoveries in pre-salt carbonate reservoirs continued, throughout the year, to yield promising results in the Santos basin. In May, Petrobras doubled the estimate for its Libra field to 12-15 billion bbl and the interest from international oil companies continues to gain momentum. The SEAL-11 block offshore the stage of Sergipe was determined to contain large amounts of high-quality light crude and natural gas (more than 3 billion bbl of oil in place, according to some sources).
Undoubtedly, with the resumption of bid rounds in 2013 (following a hiatus that started in 2009 as the government established the pre-salt regulatory frame- work), many believe that Brazil is going to continue to attract inward investment.
The Arctic In 2008, the US Geological Survey estimated that the undiscovered, technically recoverable hydrocarbon reserves in the Arctic include 90 billion bbl of oil, 1670Tcf of natural gas, and 44 billion bbl of natural gas liquids. These figures suggest that the region will add greatly to the undiscovered conventional global hydrocarbon reserves.
Russia is actively ramping up its exploration activities and engagement with international oil industry players to explore its offshore potential in the Barents and Pechora Seas. Recently, PGS together with Geology Without Limits, acquired a regional program of 2D covering the Barents and Kara Seas within the framework of an international scientific program.
We’ve also been working for many years on the Norway side of the Barents Sea. Here, the Wisling and Skrugard discoveries have created a lot of interest. OMV recently released news of a discovery in September 2013, uncovering a reservoir that could contain up to 160MMbbl of recoverable oil. Statoil and OMV also announced another discovery in the Hoop area of the Norwegian Barents Sea in the same month, expected to range from 65-165MMbbl of oil. Oil companies are increasing their focus on the Barents Sea, with several wells in the pipeline. The previously disputed zone with Russia is being opened up, with the Norwegian government encouraging the acquisition of new data to enable the exploration of this area that is thought to have high hydrocarbon potential.
2013 has been a good year for Australia, with a continued natural gas discoveries in the Carnarvon basin offshore Western Australia and one of the biggest onshore oil discoveries ever at Coober Pedy.
Since 2009, there have been 21 offshore discoveries, which together amount to 10Tcf. Apache and Santos, in particular, have had success in 2013 finding gas offshore Western Australia. Eni successfully drilled the Evans Shoal North-1 appraisal well in the Timor Sea. Chevron also had success in April 2013 in the Carnarvon basin, encountering about 40m of net gas pay in the upper Mungaroo sands at the Elfin-1 well. Santos has had a string of successes in the Jurassic Angel and Triassic Mungaroo formations in the Carnarvon basin, as well as those at Crown, Bassett West, and Bianchi. Shell has flagged that innovation will play a key role in the competitiveness of Australia’s LNG industry, as global production grows substantially in the next decade, with supply from several sources expected to rise significantly.
Generally within Southeast Asia, advances in deepwater production technology, innovations in circumventing the lack of infrastructure in some parts of the region, and the strong growth in the regional gas market in Asia also mean projects previously considered economically unviable are now being explored again.
Europe Offshore Europe is a more mature but competitive area, with recent new large discoveries ensuring that it remains in many oil companies’ exploration plans. The potential of this region is exciting: the Norwegian Petroleum Directorate (NPD) currently estimates undiscovered recoverable resources on the Norwegian Continental Shelf (NCS) at 935-5420 million scm oe. The UK government’s Department of Energy and Climate Change suggest that UK oil reserves range from 405-1064 million tonnes and natural gas reserves range from 244 - 699bcm for fields already in production, under development, or where development plans are in discussion.
Image Caption:Ramform Titan acquired her first multi-client survey in Northwest Europe in 2013.
The NPD states that there are currently 40 confirmed plays across the NCS and 33 additional unconfirmed plays, one of which will enter the confirmed list for 2014 following the recent Gohta discovery in the Barents Sea. The Gohta discovery (7120/3-1 well, October 2013) proved petroleum in a Permo- Carboniferous carbonate reservoir (Røye Formation). A 25m gross gas column was found above a 75m gross oil column in karstified and dolomitized limestone. With technological advances helping to image the subsurface more than ever before, the ability to find such resources should improve significantly.
Ireland is an area which is experiencing an upsurge in industry interest, with drilling likely in 2014 following the 2013 Dunquin North well in the Porcupine basin. PGS has acquired a 3000km 2D survey to better delineate the Fastnet and Celtic basins area to the southwest of the Barryroe field. This was acquired simultaneously with towed electromagnetic data, with some impressive results.
There are, of course, many other areas that I haven’t mentioned that the industry would consider having very strong potential. The opportunity to constantly explore and forge new ground is what makes this industry such an interesting place to be in. The risk involved is part and parcel, but our focus is on investing in new technology, utilizing innovative techniques and geological understanding to reduce that risk. We’re keeping an eye on the areas around the world that show the best exploration potential – and this continues to inform our seismic acquisition strategy. OE
Tom Ziegler is Vice President of Global MultiClient at Petroleum Geo- Services, based in London. He joined PGS in 1995, focused on exploration offshore Europe and Africa, and became head of MultiClient for EAME in 2003. Prior to PGS, he worked as a North Sea geologist for Clyde Petroleum. Ziegler earned a BSc in Petroleum Geology at Imperial College London and an MBA at the University of Strathclyde.