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Petroleum Geoscience
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Introduction

As introduced in a previous Seismic Tech-Notes article on Separated Wavefield Imaging [‘SWIM’], SWIM uses both the up-going pressure wavefield (‘P-UP’) and down-going pressure wavefield (‘P-DWN’) from the dual-sensor wavefield separation of GeoStreamer 3D data to fundamentally change the way that seismic migration can image the subsurface, the first 1 km or so below the surface in particular. Broadband and continuous seismic images all the way up to, and including, the seafloor seismic event—even in areas with very shallow water and where the 3D seismic surveys have towed a very large streamer spread to optimise survey efficiency. Every receiver from every streamer becomes a ‘virtual source’, thereby greatly extending the spatial extent of the migrated images, most famously mitigating the cross-line acquisition footprint associated with all 3D streamer surveys, notably those in shallow water, using large streamer spreads and with shallow targets of interest. A common vernacular has also been to describe SWIM as imaging ‘All orders of surface multiples’, which it does, but a better description is that ‘The complete seismic wavefield is being imaged’.

I discuss the power of SWIM to contribute to shallow velocity model building, imaging and interpretation below, building a platform to discuss seismic inversion and quantitative interpretation (QI) in a future article.

Shallow Velocity Model Building

Figure 1 compares shallow image gathers imaged from GeoStreamer data with Kirchhoff PSDM versus SWIM. Anyone familiar with seismic processing will understand that the fold on shallow arrival times/depths is always very small because of the combination of the 3D multi-streamer acquisition geometry and the outer trace mute applied in processing. In the worst case at the outer streamer locations for wide-tow geometry and/or shallow water areas there will in fact be zero fold for shallow depths and a very strong acquisition footprint will corrupt the shallow seismic data. The upper part of Figure 1 displays this well-known lack of shallow fold using Kirchhoff pre-stack depth migration (PSDM). Almost unbelievably, the lower part of Figure 1 illustrates how the introduction of P-DWN into a modified form of depth migration (SWIM) enables all offsets for all depths to contribute useful information using the same (GeoStreamer) survey data.

Whilst the events in the upper part of Figure 1 appear to be ‘flat’ and would satisfy a seismic processing expert picking velocities, anyone can see that it is very challenging trying to assess the ‘flatness’ of such short seismic events. In contrast, every event in the lower part of Figure 1 enables a very accurate assessment of the offset-dependent quality of the velocity model at all two-way time (TWT) or depth. Indeed, it is apparent in the SWIM gathers that the velocity model used is in fact slightly inaccurate at the far offsets (‘undercorrected’), and more sophisticated high-order/multi-offset/anisotropic velocity corrections can be applied, tested and refined with confidence. The use of SWIM in ‘Complete Wavefield Imaging’ (CWI) velocity model building has now become commonplace.

It is worth reminding ourselves that the ‘structural stability’ of depth imaging is rather useless without very accurate shallow velocity control. The 3D spatial integrity of the structures imaged, the juxtaposition of events across faults, the pull-up/push-down influence of near-surface velocity heterogeneities upon seismic-to-well ties, the ability to accurately quantify the volumes of prospects, and so on, all depend upon the seismic depth range where we historically have the worst understanding—the first 1 km below the surface.

Near Angle Illumination

It is worth noting that all SWIM events are naturally zero phase at all depths, and the angle coverage/illumination is substantially improved by comparison to conventional image gathers—particularly in terms of near-angle coverage. These considerations contribute to the spatial resolution of shallow features associated with SWIM depth slices. Whilst minimum angles in excess of 25° are routinely observed in the first 0.5 seconds on conventional angle gathers in shallow water depths (less than 300 m), the minimum angles observed on SWIM angle gathers are routinely less than 5°. This becomes particularly relevant for seismic inversion and AVO studies. We also observe in the lower part of Figure 1 that stable far angle information is available past 42° in this particular example—both because the velocity model used to convert offset to angle can be more accurate and because significantly larger offsets are imaged.

Velocity model building in complex geological regimes is increasingly moving towards using angle domain common image gathers (ADCIGs) as the preferred platform rather than traditional offset domain gathers. The challenges observed in Figure 2 are therefore also relevant to shallow velocity model building in addition to seismic inversion where small minimum incidence angles are critical to derive accurate AVO incidence and gradient information—the application for angle stacks discussed in a future article. As we will see, SWIM image gathers have densely sampled angle information for all angles of interest and all depths of interest.

Seismic Survey Geoscience
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Your Weekly Update: 10 - 14 December 2018

Market Watch

Headline crude prices for the week beginning 10 December 2018 – Brent: US$62/b; WTI: US$52/b

  • Crude prices strengthened at the start of this week, with OPEC delivering an agreement that will see production across the OPEC+ alliance decline by 1.2 mmb/d beginning January 2019
  • Two-thirds or 800,000 b/d of the cut will be borne by OPEC – with most of it taken up by Saudi Arabia – while the non-OPEC group will take up a cut of 400,000 b/d, most of which will be taken up by Russia
  • Skepticism has reigned before the supply deal was reached, as the first day of the OPEC meeting in Vienna closed without consensus and the threads holding OPEC together showed some stress when Qatar decided to quit the group
  • Crude prices were also boosted by Libya declaring force majeure at its largest oil field at El Sharara over arm protests, while Canada’s Alberta province announced plans to pare back some 325,000 b/d of output to ease a huge glut
  • The coordinated supply deal by OPEC ‘was not easy’ according to UAE Minister of Energy and Industry, with Iran in particular balking at being asked to sign up to a symbolic cut; this might not augur well for future supply deals that might be necessary given current trends
  • However, the supply cut will only last until April 2019, when the terms are due for a review, which would give OPEC+ enough time to consider and deal with the expiration of American waivers for eight countries over continued import of Iranian crude in May
  • Meanwhile, America became a net oil exporter for the first time in almost 75 years, as the unprecedented boom in US crude oil fuelled by the shale revolution powers on, a development that could dilute OPEC+’s attempt to support global crude prices
  • The recent weakening of WTI prices saw the US lose 10 active oil rigs last week, however, the addition of 9 new gas rigs led to a net loss of only 1 in the Baker Hughes active US rig count
  • Crude price outlook: OPEC+’s decision might have provided some relief, but may not be enough to keep crude oil prices trending upwards. Expect prices to moderate to US$60-61/b for Brent and US$50-51/b for WTI

Headlines of the week

Upstream

  • ExxonMobil’s winning streak in Guyana continues, as it announces its 10th offshore discovery at the Pluma-1 well, boosting estimated recoverable resources in the Stabroek block by almost 1 mmb/d to over 5 mmb/d
  • Apache has initiated production at the Garten field in the UK North Sea, with an output rate of 13,700 b/d and 15.7 bcf/d of natural gas
  • Chevron has raised its capital expenditure for the first time since 2014 into US$20 billion, with a major focus on expanding operations in the Permian Basin as well as on the Tengiz megaproject in Kazakhstan
  • Canada’s Alberta province, weighed down by a supply glut caused by pipeline bottlenecks, has announced moves to reduce the region’s output by 325,000 b/d
  • Equinor and Faroe Petroleum have agreed to trade a number of assets in the Norwegian Sea and the Norwegian Continental Shelf North Sea, encompassing the Njord, Bauge Hyme, Vilje Ringhome, Marulk and Alve fields, with the deal described as a ‘balanced swap’ in terms of value with no cash consideration

Downstream

  • CNPC’s US$9.53 billion joint venture integrated 400 kb/d petrochemicals/refinery project with PDVSA in Jieyang, China has been reactivated, and is now expected to begin operations in late 2021
  • French president Emmanuel Macron has backtracked and suspended a planned fuel-tax hike, after weeks of violent riots by the so-called Yellow Vests grassroot groups of up to 300,000 protestors
  • Limetree Bay Ventures has secured US$1.25 billion in financing that paves the way for the Limetree Bay refinery in the US Virgin Islands to restart after being idled for years, partnering with BP Products North America on the project

Natural Gas/LNG

  • Equinor has received permission from the Norwegian government to proceed with the development of Troll Phase 3, delivering an additional 2.2 billion boe/d of natural gas with a planned start-up timeframe of 1H2021
  • Shell has completed the construction of Gibraltar’s first LNG regasification facility, a small-scale project that will feed a new power plant in the territory
  • Trinidad and Tobago has agreed to allow BP and Shell to extend the operational life of the Atlantic LNG Train 1 in Point Fortin by five years, with the country receiving the ability to sell LNG cargoes through its state gas firm
  • Tokyo Gas and the Philippines’ First Gen Corporation have signed a joint development agreement to build and operate an LNG receiving terminal, as the three-horse race narrows over the country’s first LNG import facility
  • American LNG player Tellurian has agreed to supply trader Vitol with some 1.5 mtpa of LNG over 15 years from its 27.6 mtpa Driftwood LNG export terminal currently being developed in Calcasiue River, Louisiana
  • Tanzania is opening talks with Equinor and ExxonMobil to launch the East African nation’s first LNG project, likely to derive gas from the Equinor-operated offshore Block 2
  • Shell is expecting to produce its first cargo of LNG from its Prelude FLNG facility in Australia before the end of 2018
December, 14 2018
Permian’s Pipeline Lifeline

The Permian is in desperate need of pipelines. That much is true. There is so much shale liquids sloshing underneath the Permian formation in Texas and New Mexico, that even though it has already upended global crude market and turned the USA into the world’s largest crude producer, there is still so much of it trapped inland, unable to make the 800km journey to the Gulf Coast that would take them to the big wider world.

The stakes are high. Even though the US is poised to reach some 12 mmb/d of crude oil production next year – more than half of that coming from shale oil formations – it could be producing a lot more. This has already caused the Brent-WTI spread to widen to a constant US$10/b since mid-2018 – when the Permian’s pipeline bottlenecks first became critical – from an average of US$4/b prior to that. It is even more dramatic in the Permian itself, where crude is selling at a US$10-16/b discount to Houston WTI, with trends pointing to the spread going as wide as US$20/b soon. Estimates suggest that a record 3,722 wells were drilled in the Permian this year but never opened because the oil could not be brought to market. This is part of the reason why the US active rig count hasn’t increased as much as would have been expected when crude prices were trending towards US$80/b – there’s no point in drilling if you can’t sell.

Assistance is on the way. Between now and 2020, estimates suggest that some 2.6 mmb/d of pipeline capacity across several projects will come onstream, with an additional 1 mmb/d in the planning stages. Add this to the existing 3.1 mmb/d of takeaway capacity (and 300,000 b/d of local refining) and Permian shale oil output currently dammed away by a wall of fixed capacity could double in size when freed to make it to market.

And more pipelines keep getting announced. In the last two weeks, Jupiter Energy Group announced a 90-day open season seeking binding commitments for a planned 1 mmb/d, 1050km long Jupiter Pipeline – which could connect the Permian to all three of Texas’ deepwater ports, Houston, Corpus Christi and Brownsville. Plains All American is launching its 500,000 b/d Sunrise Pipeline, connecting the Permian to Cushing, Oklahoma. Wolf Midstream has also launched an open season, seeking interest for its 120,000 b/d Red Wolf Crude Connector branch, connecting to its existing terminal and infrastructure in Colorado City.

Current estimates suggest that Permian output numbered around 3.5 mmb/d in October. At maximum capacity, that’s still about 100,000 b/d of shale oil trapped inland. As planned pipelines come online over the next two years, that trickle could turn into a flood. Consider this. Even at the current maxing out of Permian infrastructure, the US is already on the cusp on 12 mmb/d crude production. By 2021, it could go as high as 15 mmb/d – crude prices, permitting, of course.

As recently reported in the WSJ; “For years, the companies behind the U.S. oil-and-gas boom, including Noble Energy Inc. and Whiting Petroleum Corp. have promised shareholders they have thousands of prospective wells they can drill profitably even at $40 a barrel. Some have even said they can generate returns on investment of 30%. But most shale drillers haven’t made much, if any, money at those prices. From 2012 to 2017, the 30 biggest shale producers lost more than $50 billion. Last year, when oil prices averaged about $50 a barrel, the group as a whole was barely in the black, with profits of about $1.7 billion, or roughly 1.3% of revenue, according to FactSet.”

The immense growth experienced in the Permian has consequences for the entire oil supply chain, from refining balances – shale oil is more suitable for lighter ends like gasoline, but the world is heading for a gasoline glut and is more interested in cracking gasoil for the IMO’s strict marine fuels sulphur levels coming up in 2020 – to geopolitics, by diminishing OPEC’s power and particularly Saudi Arabia’s role as a swing producer. For now, the walls keeping a Permian flood in are still standing. In two years, they won’t, with new pipeline infrastructure in place. And so the oil world has two years to prepare for the coming tsunami, but only if crude prices stay on course.

Recent Announced Permian Pipeline Projects

  • September 2018 – EPIC Midstream Holdings – 675,000 b/d, 1125km, 24-30’ diameter, 4Q19 target opening
  • November 2018, Wolf Midstream Partners – 500,000 b/d, 65km, 16’ diameter, 2H2019 target opening
  • November 2018, Jupiter Energy – 1 mmb/d, 1050km, 36’ diameter, 2020 target opening
  • December 2018, Plains All American Pipeline – 575,000 b/d, 830km, 26’ diameter, 3Q19 target opening
December, 04 2018
Your Weekly Update: 3 - 7 December 2018

Market Watch

Headline crude prices for the week beginning 3 December 2018 – Brent: US$61/b; WTI: US$52/b

  • After falling down to fresh lows last week – with WTI prices dipping below US$50/b at one point – crude oil prices improved after the G20 meeting in Buenos Aires, where the US and China agreed to a temporary truce over their trade war
  • While no concrete agreements over energy were announced at the G20 summit, the slightly thawing in trade tensions allowed crude benchmarks to rise slightly, assisted by an announcement by Canadian producers in Alberta that output would be cut by 325,000 b/d beginning January
  • Russia and Saudi Arabia agreed at the G20 summit to extend the OPEC+ deal into 2019, suggesting that a coordinated oil output cut was in the works, also supported prices ahead of OPEC’s meeting in Vienna this week
  • Not present at the OPEC meeting, however, will be Qatar, which quit the oil cartel in a surprise move; the tiny sultanate said it was quitting due to its small oil production, choosing instead to focus on its LNG industry, but the move can be seen as a response to the Saudi-led boycott of Qatar, calling into question Saudi Arabia’s ability to hold the fragile OPEC coalition together
  • Consensus among analysts point to OPEC+ agreeing to remove some 800,000 b/d of crude oil from the market beginning January, aimed at establishing a floor for oil prices at some US$65/b
  • The downward spiral of crude prices has put the brakes on US drilling activity, with 2 new oil rigs offset by the loss of 5 gas rigs last week; analysts are expecting shale explorers to cut spending budgets in 2019 in response to weak prices, raising spectres of the 2015 price slump
  • Crude price outlook: Ahead of the OPEC meeting on December 6, crude should be kept up by expectations of a renewed supply cut, with Brent likely to trade rangebound around US$61-63/b and WTI at US$52-53/b

Headlines of the week

Upstream

  • Buoyed by the prolific nature of the Permian Basin, Shell has announced plans to nearly double its production in the shale patch with AI-powered technology
  • China and the Philippines have set aside sovereignty issues, signing an agreement for joint exploration and development in the South China Sea
  • Facing severe pipeline bottlenecks, Canada’s Alberta province is looking to purchase rail cars to ship more crude oil by train out of the province towards the US, as a temporary measure while new pipeline are proposed and built
  • Shell has completed the sale of Shell E&P Ireland to Nephin Energy Holdings, which includes a 45% in the Corrib gas venture, for US$1.3 billion
  • In Norway, Shell also sold its interests in the Draugen and Gjøa fields for US$526 million to OKEA AS, but retains its interests in the Ormen Lange and Knarr fields, as well as the Troll, Valemon and Kvitebjørn projects
  • Petrobras has sold its stake in 34 onshore production fields to Brazilian firm 3R Petroleum for US$453.1 million, as well as stakes in three shallow-water offshore fields off Rio de Janeiro to Perenco for US$370 million
  • Pemex tripled its estimated reserves in the Ixachi field to 1.3 billion barrels of oil, calling it the ‘most important onshore field in 25 years’ and expecting peak production of 80,000 b/d of condensate and 720 mscf/d of gas by 2022

Downstream

  • Uganda has pushed back the opening of its first oil refinery to 2023, in line with estimates by Total, CNOOC and Tullow Oil, as crude oil production is now only expected to begin in 2021
  • Malaysia will be introducing a B10 biodiesel mandate in December over a phased rollout, with complete implementation expected by February 2018
  • Pertamina expects to begin works on upgrading its Balikpapan refinery in early 2019, aimed to increasing fuel standards to Euro V and upgrading capacity to process sour crude together with its current medium heavies
  • ExxonMobil plans to upgrade its Rotterdam refinery to expand Group II base stock production, following the installation of a new hydrocracker
  • The US EPA has increased its annual blending mandate for advanced biofuels by 15% and kept conventional biofuels blending requirement steady for 2019, while maintaining waivers for selected refineries

Natural Gas/LNG

  • Petronas and Vitol Asia have signed a long-term LNG supply agreement, with Petronas providing LNG from the LNG Canada project in Kitimat, providing up to 800,000 tons per annum for 15 years beginning 2024
  • Eni and Anadarko have been giving a 2023 deadline to submit key development plans for the Area 1 and 4 LNG complex in Mozambique
  • Tullow Oil is backing the attempt by three former Cove Energy executives in the Comoros Islands by taking stakes in Discover Exploration’s blocks, hoping to repeat the trio’s success in discovering the Rovuma block
  • South Korea’s Posco Daewoo has signed a deal with Brunei National Petroleum Company to jointly explore LNG opportunities in Brunei, with specific focus on the development of the Dehwa area operated by Posco Daewoo
  • Rosnedt and the Beijing Gas Group have set up a joint venture focusing on building and operating a network of up to 170 CNG fuel stations in Russia, using LNG as motor fuel
December, 06 2018