Putting seismic in perspective

Andrew McBarnet
Friday, July 9, 2010

Andrew McBarnet provides a commentary on seismic matters at the EAGE's Annual Meeting held in Barcelona last month.

The European Association of Geoscientists & Engineers (EAGE) can rarely be faulted for its choice of venue for its annual meetings. Certainly no one was complaining at this year's event held in Barcelona, a happening city if ever there was one, which also has excellent conference and exhibition facilities. The capital of the Catalonian region appears to be defying some of the gloom affecting Spain's economy, largely thanks to the inspired rejuvenation process prompted by the infrastructure spending associated with the 1992 Olympics. Tourists flock to the city, and the port is now the self-styled cruise capital of Europe.

Venues for these meetings may be more significant than we suppose, even the anticipation of attending. It is a matter of setting the mood, and in this respect EAGE certainly has an unfair advantage over the Society of Exploration Geophysicists (SEG), its US counterpart. SEG members are locked for the most part into a circuit of Houston, Denver, San Antonio and New Orleans, with an occasional foray to Dallas or Las Vegas. This doesn't quite compare with great European cities such as Amsterdam, Paris, London, Vienna, Rome, Florence and Madrid which have featured on the EAGE calendar in recent years.

There also seems to be a difference between the approaches to annual meetings between the two professional societies. With the exception of its outing to Las Vegas last year (to be repeated in 2012), SEG seems to put priority on ensuring that its venues have some oil industry relevance. The thinking is that individual members, exhibiting companies and sponsors have a reasonable expectation of local support and are not stuck in some outlandish place where only the most dedicated will visit. This was somewhat the case for Salt Lake City in 2002, compared with the other SEG visit outside its usual routine to Calgary, Canada's oil capital.

EAGE, on the other hand, believes that a desirable European city will counter any worries about whether the venue has a local oil industry. Some years ago it pushed the limit of tolerance by holding the annual meeting in Helsinki, admittedly in 1999 just when the E&P industry and seismic in particular had just started spiralling downward. That event was not well attended, but otherwise its venue strategy has been largely vindicated.

It helps too that EAGE invests more in the social events where members can mix in a less formal setting.

So when everyone arrived in Barcelona last month, the unfolding Deepwater Horizon disaster in the Gulf of Mexico seemed curiously distant even if its impact on the seismic business is expected to be detrimental, at least in the short term. Dignitaries at the opening ceremony session certainly didn't want to get into that, talking platitudinously instead about how geoscientists and engineers could lead the way in meeting the world's energy requirements in an environmentally friendly way. Tim Cejka, ExxonMobil Exploration president, only made oblique reference to the catastrophe.

At the CGGVeritas client evening, chairman and CEO Robert Brunck said what most people admit off the record, that the accident could have happened to any company. It was a time, he added, for the industry to come together and find solutions for the future. The evening was actually something of a special occasion as Brunck is handing over the CEO reins to Jean-Georges Malcor, formerly senior vice president at Thales. During Brunck's 11 years in charge, Compagnie Générale de Géophysique (CGG), as it was, grew dramatically, working to a strategy laid down in the late 1990s to expand all its services - especially the contribution to the group made by Sercel, its subsidiary which manufactures marine and land seismic acquisition equipment.

The 1999-2002 downturn in the seismic business did not deflect the company from its objectives, some of which were realised by acquisition, most notably the 2007 tie-up with competitor Veritas DGC. Brunck's contribution to the industry was acknowledged by the president of the EAGE, Mahmoud Abdulbaqi, with the presentation of a guitar which Brunck then gamely agreed to play, accompanied by a Flamenco band on hand. Scarcely had a rather Latin version of Let it be finished when Brunck was stunned by the introduction of special guest Manitas de Plata, now 89 years old and as legendary to Flamenco guitar as Eric Clapton is to rock.

Data quality
On its stand at the exhibition, CGGVeritas attracted plenty of attention with the launch of its BroadSeis acquisition technique, clearly meant to be the company's answer to Petroleum Geo-Services' (PGS) very successful introduction of its GeoStreamer technology. PGS is so confident about the improvements in data quality achievable with GeoStreamer that it is upgrading the imaging of key producing North Sea areas with a series of multi-client 3D surveys. Over 5000km2 of 3D data will be acquired in the Viking and Central Grabens this summer.

PGS says that recent North Sea GeoStreamer data sets offer expanded frequency bandwidth by combining data from co-located pressure and particle velocity sensors. The dual sensor system enables far better imaging of deeper structures, whilst retaining very high frequency detail in the shallower sections. Another benefit is that the data is sampled in the quieter and operationally more efficient environment of a deeper tow. PGS-patented processing of the wavefields allows the separation of upgoing and downgoing signals and removal of the receiver ghost, an important breakthrough.

CGGVeritas says that its BroadSeis system uses notch diversity and patented processing technology to yield a broadband spectrum taking full advantage of the low noise and low-frequency response of its Sentinel solid streamer manufactured by Sercel. The notch diversity from a variable streamer depth profile creates an exceptionally sharp and clean wavelet for interpretation which can be tuned for different water depths, target depths, and desired output spectra.

As it is said to require only a single streamer and uses a fully 3D deghosting algorithm, BroadSeis is equally suitable for 2D, 3D and wide-azimuth recording. There are apparently no complications in either the data acquisition or the deghosting technique, particularly in the crossline direction. Because BroadSeis needs no new equipment where solid streamers are already deployed, it will be immediately available on 75% of CGGVeritas vessels.

Timing of the BroadSeis launch at the EAGE was vaguely reassuring, demonstrating that companies are not unnerved by happenings in the Gulf of Mexico and continue to seek a technology edge for their operations around the world.

In other words, business as usual. There was certainly no definitive word on what marine seismic contractors can expect in the aftermath of the Deepwater Horizon disaster. From a market perspective, the main concern continues to be the fate of the wide-azimuth (WAZ) multi-client survey programmes being conducted in the Gulf of Mexico by the major players. These multi-vessel seismic surveys are operationally complex and expensive to carry out, but are deemed valuable as they provide fresh insight into complex geological settings such as the difficult-to-image subsalt.

The fear is that if deepwater Gulf of Mexico leasing or operations in general are slowed or suspended for any length of time, then oil companies will not continue to invest in the WAZ surveys being planned or in the data already available. In theory this would leave some of the marine contractors' best vessels looking for work elsewhere in the world. The optimists suggest that the impact of this unexpected addition of available vessels might not be too harmful to the market if some potentially valuable WAZ projects outside the Gulf of Mexico were brought forward, thereby creating some sort of continuity for WAZ crews.

In Barcelona, some were also suggesting that marine geophysical surveys could be in greater demand in the Gulf of Mexico and anywhere else in the world where regulators and oil companies are reviewing their operational methods.

The fact is that seismic and other geophysical techniques are increasingly being developed to better image potential drilling hazards such as unstable shallow gas pockets. Indeed, it is not so far-fetched to speculate that regulators may insist on the highest resolution possible imaging of planned drilling locations before operations can be sanctioned.

Given the uncertainty and the competition for surveys, Polarcus must have been pleased to announce two new contracts immediately after the Barcelona event. The Dubai-based marine geophysical contractor with a fleet of new vessels being launched is to co-operate with the Russian company Dalmorneftegeophysica (DMNG) in a project for Rosneft to carry out a 1030km2 3D seismic acquisition project in the Russian sector of the Black Sea. The 40-day survey is to be acquired by Asima, the third and largest vessel to date in the Polarcus fleet. The company says it is also to acquire a 3D seismic survey for OMV in the Norwegian sector of the Barents Sea using its 12-streamer Naila vessel.

Although the work is not exactly flooding in for Polarcus, every project successfully completed adds to the company's resumé. It makes it just that bit easier to convince sceptical potential oil company clients that Polarcus may be a new company, but has state-of-the-art equipment and can get the job done.

Serious consideration
In Barcelona, controlled source electromagnetic survey (CSEM) specialists Electromagnetic Geoservices (EMGS) and Offshore Hydrocarbon Mapping (OHM) both hinted that oil companies were once again giving serious consideration to the potential benefits of the technology after a hiatus which has financially stretched both companies. EMGS announced last month a minimum $150 million multi-year 3D EM contract from what it coyly described as one of the largest oil companies in the world, but which sources say is ExxonMobil. The campaign will employ one of the company's purpose-built 3D EM vessels such as the BOA Galatea or BOA Thalassa continuously in order to maximise vessel utilisation levels.

Roar Bekker, EMGS CEO, called the contract award a giant step forward for EMGS. 'A long-term project such as this provides us with a solid platform for future growth and allows us to manage our vessel utilisation far more efficiently. EMGS has previously provided services for this customer, and this significant award is a major statement of confidence in our advanced 3D products and high-capacity vessels. More importantly, it is a sign that EM technology is entering the mainstream of exploration and production workflows.'

Rather more modestly, OHM has won some work for its OHM Express vessel worth in excess of $1 million. It will provide its WISE (well integration with seismic and electromagnetic) service to Bridge Energy UK consisting of a fully integrated dataset of seismic, CSEM and well information. Richard Cooper, OHM CEO, said that CSEM works best when tightly integrated within a framework constrained by seismic and well data.

PGS arrived in Barcelona with a significant feather in its cap regarding the future of fibre-optic solutions in life of field seismic reservoir monitoring. The company had just signed with Petrobras an agreement to install a permanent seismic reservoir monitoring system at Brazil's massive deepwater Jubarte field in the North Campos Basin. PGS is to provide and install its OptoSeis fibreoptic system, as well as perform seismic acquisition and data processing for the project. The only other fibre-optic system is being placed at ConocoPhillips' Ekofisk field using the CGGVeritas Optoplan system (previously owned by Wavefield Inseis before its merger).

The contract is something of a coup for PGS as it was won against all the other main contenders offering fibreoptic solutions to life of field seismic. The initial project covers a portion of the Jubarte field that is over 245km2 in water depths of 1240-1350m.

Depending on the results the project could grow to cover the entire field. This could herald a significant step forward in claims for the value of fibre-optic in life of field seismic given that the original systems developed by BP for the Valhall, Clair and Azeri-Chirag-Guneshli fields are based on buried conventional ocean bottom cable recording equipment.

The fact that Petrobras, destined to be a major deepwater producer for many decades, is instigator of this project could be good news for advocates of life of field seismic, which has still not caught on even with many of the largest oil companies. Sceptics suggest that companies are not particularly interested in investing in such reservoir surveillance over a long period with uncertain outcome when towed streamer and non-permanent ocean bottom recording systems may offer a more affordable and less risk-laden solution.

Meanwhile Stingray, which had hoped to be the fibre-optic solution provider for the Jubarte project, announced in time for Barcelona that it was linking up with another British company, Ikon Science, to develop new time-lapse technology and services. OE

Categories: Technology Engineering Geophysics Geology

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