Despite depressed oil prices, the Gabonese 11th deepwater licensing round has generated considerable interest from both International Oil Companies (IOCs) and newcomers alike, encouraged by the success of exploration in the conjugate margin offshore Brazil, as well as recent pre-salt discoveries such as Ruche, Tortue, Diaman and Leopard in nearby Gabonese waters. CGG has worked directly with the Direction Generale des Hydrocarbures of Gabon (DGH) to acquire and process over 25,000 km2 of new 3D BroadSeis™ multi-client seismic data over available and licensed blocks in the South Basin to enable evaluation of this prospective area. A fast-track pre-stack time-migrated dataset for this survey is available now, along with sample pre-stack depth reverse time-migrated (RTM) data in one area. The final RTM for the whole of the survey area will be available this summer.
The objective of the survey is to image potential prospective structures at base salt level without compromising the shallower post-salt image quality. The data do not disappoint. Even a preliminary ultra-fast-track dataset produced onboard was described as “way beyond expectations” by a major oil company interpreter. On the full fast-track dataset, more detail below the salt is being revealed than has ever been seen before, revolutionising the understanding of the geology of the area. Early seismic imaging results indicate the presence of thick syn-rift and sag sequences below the salt, which are the key intervals of a pre-salt petroleum system and indicate many exciting prospects, some of which continue beyond the borders of the survey so that their full extent cannot be gauged.
This survey is being processed using the latest high-end imaging technology to produce the clearest images. The fast-track PSTM volume shows clear uplift over the existing data, while the fast-track PSDM shows the full benefits of advanced velocity modelling and depth-migrated modern broadband 3D seismic data. The uplift in subsalt imaging that will be achieved in the final dataset is dramatic; the RTM fully depth-migrated example line shows clearly defined tilted fault blocks and horst features as well as the highly complex nature of the thrusted and distorted salt and sediment overburden.
Multi-layer tomography (TomoML) and full waveform inversion (FWI) are being used to create the final velocity model, with RTM being used in the velocity model building iterations. The high-quality, low-frequency data acquired using the BroadSeis solution is particularly beneficial for FWI as the low frequencies prevent cycle-skipping. The imaging improvement from the FWI velocity model can be seen both in the shallower section, where pull-up/push-down image distortions are precisely corrected, and in the deeper salt bodies, where salt flanks and subsalt reflectors show improved focus and continuity due to better overburden description.
Although this dataset delivers unprecedented images of the subsurface in this area, additional data are being acquired to improve the imaging still further in the most complex geology to the southeast of the survey. Tailored multi-vessel survey design is enabling longer offsets, up to 14 km in the same orientation as the original data, to be acquired over block F14. In block F15, adjacent to the Congo border, a second orthogonal azimuth of the full range of offsets, including those up to 14 km, is being acquired. Longer offsets and dual azimuths are expected to improve the sub-salt illumination and provide even greater clarity of the most challenging structures. In order to acquire these long offsets an additional source vessel is being deployed. Synchronised source technology and blended acquisition are being used to enable the shot interval to be less than the record length, so that source density, and therefore fold of coverage, can be maintained.
All the survey data form the centrepiece of an integrated geoscience project which will include interpretation of the gravity data acquired with the seismic to analyse the deep structure of the basin, analysis of the key wells in the area, full seismic interpretation in the depth domain with integration of satellite seep data to identify potential natural hydrocarbon escape conduits and production of palaeogeographic, reservoir distribution and source rock maturity maps of key stratigraphic intervals, among other products. Integrated studies are becoming increasingly popular as they provide a single validated source for information and each individual part is improved by understanding the requirements of the larger project. Large multi-client surveys also provide a cost-effective means of acquiring high-quality 3D seismic data which allows oil companies to reduce their exploration risk in both mature and frontier areas and helps to reduce the time required from licensing award to drilling wells.
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Headline crude prices for the week beginning 18 March 2019 – Brent: US$67/b; WTI: US$58/b
Headlines of the week
Midstream & Downstream
Risk and reward – improving recovery rates versus exploration
A giant oil supply gap looms. If, as we expect, oil demand peaks at 110 million b/d in 2036, the inexorable decline of fields in production or under development today creates a yawning gap of 50 million b/d by the end of that decade.
How to fill it? It’s the preoccupation of the E&P sector. Harry Paton, Senior Analyst, Global Oil Supply, identifies the contribution from each of the traditional four sources.
1. Reserve growth
An additional 12 million b/d, or 24%, will come from fields already in production or under development. These additional reserves are typically the lowest risk and among the lowest cost, readily tied-in to export infrastructure already in place. Around 90% of these future volumes break even below US$60 per barrel.
2. pre-drill tight oil inventory and conventional pre-FID projects
They will bring another 12 million b/d to the party. That’s up on last year by 1.5 million b/d, reflecting the industry’s success in beefing up the hopper. Nearly all the increase is from the Permian Basin. Tight oil plays in North America now account for over two-thirds of the pre-FID cost curve, though extraction costs increase over time. Conventional oil plays are a smaller part of the pre-FID wedge at 4 million b/d. Brazil deep water is amongst the lowest cost resource anywhere, with breakevens eclipsing the best tight oil plays. Certain mature areas like the North Sea have succeeded in getting lower down the cost curve although volumes are small. Guyana, an emerging low-cost producer, shows how new conventional basins can change the curve.
3. Contingent resource
These existing discoveries could deliver 11 million b/d, or 22%, of future supply. This cohort forms the next generation of pre-FID developments, but each must overcome challenges to achieve commerciality.
Last, but not least, yet-to-find. We calculate new discoveries bring in 16 million b/d, the biggest share and almost one-third of future supply. The number is based on empirical analysis of past discovery rates, future assumptions for exploration spend and prospectivity.
Can yet-to-find deliver this much oil at reasonable cost? It looks more realistic today than in the recent past. Liquids reserves discovered that are potentially commercial was around 5 billion barrels in 2017 and again in 2018, close to the late 2030s ‘ask’. Moreover, exploration is creating value again, and we have argued consistently that more companies should be doing it.
But at the same time, it’s the high-risk option, and usually last in the merit order – exploration is the final top-up to meet demand. There’s a danger that new discoveries – higher cost ones at least – are squeezed out if demand’s not there or new, lower-cost supplies emerge. Tight oil’s rapid growth has disrupted the commercialisation of conventional discoveries this decade and is re-shaping future resource capture strategies.
To sustain portfolios, many companies have shifted away from exclusively relying on exploration to emphasising lower risk opportunities. These mostly revolve around commercialising existing reserves on the books, whether improving recovery rates from fields currently in production (reserves growth) or undeveloped discoveries (contingent resource).
Emerging technology may pose a greater threat to exploration in the future. Evolving technology has always played a central role in boosting expected reserves from known fields. What’s different in 2019 is that the industry is on the cusp of what might be a technological revolution. Advanced seismic imaging, data analytics, machine learning and artificial intelligence, the cloud and supercomputing will shine a light into sub-surface’s dark corners.
Combining these and other new applications to enhance recovery beyond tried-and-tested means could unlock more reserves from existing discoveries – and more quickly than we assume. Equinor is now aspiring to 60% from its operated fields in Norway. Volume-wise, most upside may be in the giant, older, onshore accumulations with low recovery factors (think ExxonMobil and Chevron’s latest Permian upgrades). In contrast, 21st century deepwater projects tend to start with high recovery factors.
If global recovery rates could be increased by a percentage or two from the average of around 30%, reserves growth might contribute another 5 to 6 million b/d in the 2030s. It’s just a scenario, and perhaps makes sweeping assumptions. But it’s one that should keep conventional explorers disciplined and focused only on the best new prospects.
Global oil supply through 2040
Things just keep getting more dire for Venezuela’s PDVSA – once a crown jewel among state energy firms, and now buried under debt and a government in crisis. With new American sanctions weighing down on its operations, PDVSA is buckling. For now, with the support of Russia, China and India, Venezuelan crude keeps flowing. But a ghost from the past has now come back to haunt it.
In 2007, Venezuela embarked on a resource nationalisation programme under then-President Hugo Chavez. It was the largest example of an oil nationalisation drive since Iraq in 1972 or when the government of Saudi Arabia bought out its American partners in ARAMCO back in 1980. The edict then was to have all foreign firms restructure their holdings in Venezuela to favour PDVSA with a majority. Total, Chevron, Statoil (now Equinor) and BP agreed; ExxonMobil and ConocoPhillips refused. Compensation was paid to ExxonMobil and ConocoPhillips, which was considered paltry. So the two American firms took PDVSA to international arbitration, seeking what they considered ‘just value’ for their erstwhile assets. In 2012, ExxonMobil was awarded some US$260 million in two arbitration awards. The dispute with ConocoPhillips took far longer.
In April 2018, the International Chamber of Commerce ruled in favour of ConocoPhillips, granting US$2.1 billion in recovery payments. Hemming and hawing on PDVSA’s part forced ConocoPhillips’ hand, and it began to seize control of terminals and cargo ships in the Caribbean operated by PDVSA or its American subsidiary Citgo. A tense standoff – where PDVSA’s carriers were ordered to return to national waters immediately – was resolved when PDVSA reached a payment agreement in August. As part of the deal, ConocoPhillips agreed to suspend any future disputes over the matter with PDVSA.
The key word being ‘future’. ConocoPhillips has an existing contractual arbitration – also at the ICC – relating to the separate Corocoro project. That decision is also expected to go towards the American firm. But more troubling is that a third dispute has just been settled by the International Centre for Settlement of Investment Disputes tribunal in favour of ConocoPhillips. This action was brought against the government of Venezuela for initiating the nationalisation process, and the ‘unlawful expropriation’ would require a US$8.7 billion payment. Though the action was brought against the government, its coffers are almost entirely stocked by sales of PDVSA crude, essentially placing further burden on an already beleaguered company. A similar action brought about by ExxonMobil resulted in a US$1.4 billion payout; however, that was overturned at the World Bank in 2017.
But it might not end there. The danger (at least on PDVSA’s part) is that these decisions will open up floodgates for any creditors seeking damages against Venezuela. And there are quite a few, including several smaller oil firms and players such as gold miner Crystallex, who is owed US$1.2 billion after the gold industry was nationalised in 2011. If the situation snowballs, there is a very tempting target for creditors to seize – Citgo, PDVSA’s crown jewel that operates downstream in the USA, which remains profitable. And that would be an even bigger disaster for PDVSA, even by current standards.
Infographic: Venezuela oil nationalisation dispute timeline