Meeting up to expectations

At the EAGE annual meeting in Vienna Andrew McBarnet discerned a mood of surprising equanimity in the marine seismic community.

Some titles are hard to live up to. So, even though the recent annual meeting of the European Association of Geoscientists in Vienna adopted the somewhat portentous theme of ‘Unconventional Resources and the Role of Technology', there wasn't much unconventional going on. That's not to say that the event was not a success. It was very well attended, there was plenty of positive talk about the health of the seismic business, the EAGE's legendary conference evening was held in the palace of the enlightened despot, Hapsburg Emperor Joseph II, and Vienna basked in sunshine all week.

Regarding that unconventional label, however, even a forum of distinguished industry speakers convened to discuss the topic didn't show much sign of thinking outside the box, preferring to stick with current corporate messages. The platform was pretty impressive including the bosses of Schlumberger (Andrew Gould), CGGVeritas (Robert Brunck) and Petroleum Geo-Services – PGS (Jon Eric Reinhardsen) plus oil company notables from Shell (Matthias Bischel), Total (Marc Blaizot), Eni (Luca Bertelli) and Statoil (Arnd Wilhems). The wild card was Cornelius Matthes from Desertec, a German organization which apparently has visions of bringing to Europe solarpowered energy from the North African desert. In a sense you had to sympathise with the contractors on the panel: none of their current business models stretches further than exploiting unconventional shale gas resources. So when asked point blank whether they were advancing technology for alternative energy, there was an inaudible response.

In fact Reinhardsen, a little disingenuously, suggested that the latest developments launched by PGS were unconventional. In this way he was able to boost the benefits of the PGS product GeoSource, which was the only significant technology launch during the week in Vienna. GeoSource is the promised sequel to the company's GeoStreamer, which in the last couple of years or so has given the company a marketing and arguably a performance edge over its chief rivals.

For PGS it's all about removing the ghost from towed-streamer marine acquisition in order to improve imaging of higher and lower frequencies, an advantage for data resolution involving complex geological settings such as the subsalt found offshore Brazil, West Africa and the Gulf of Mexico. The ghost exists in conventional marine towed seismic acquisition because the hydrophone sensor embedded in the streamer at a depth below the water surface, records both the upgoing wavefield coming from the earth, but also an undesirable downgoing wavefield (which constitutes the ghost) reflected from the water surface.

In the GeoStreamer, a velocity sensor (or geophone, as used in land seismic operations) is also deployed in the streamer, together with the hydrophone. This is so both the pressure wavefield (via the hydrophone) and the vertical particle velocity wavefield (via the geophone) can be recorded in order to eliminate the receiver ghost. In addition the streamer is towed at a lower and hence quieter depth (15–25m) than the conventional streamer depth. Using its proprietary processing of the recorded wavefields PGS can separate upgoing and downgoing signals and remove the receiver ghost. According to the company, the result is broadband seismic data capable of imaging deeper and more complex structures, and producing a clearer image capable of significantly reducing the uncertainty in exploration and development decisions.

At Vienna PGS introduced GeoSource which applies the same principles to remove ghosting by the airgun shooting source in marine seismic acquisition. PGS has a rather neat photographic representation of the full Geostreamer and GeoSource effect. By reducing the extended combined ghost function of the source and receiver to a single spike, the resultant effect on the resolution of the seismic data is obvious as illustrated in the photographs. The top photograph has two ghosts which have been added with exactly the same polarity reversal as the two sea surface ghosts. The vertical structures clearly show two distinct bands (one black and one white) to their right hand side. The centre photograph contains only a single ghost (white band on the right). This picture is clearer but is still unclear because of the single ghost. The bottom photograph is ghost free, and the resolution in this case is only limited by the intrinsic bandwidth (pixel resolution) of the photograph. Removing one ghost is an improvement, but the combination of removing both ghosts brings the picture into complete clarity. The effect in seismic data is said to be completely analogous.

Not to be totally outdone, CGGVeritas announced during the meeting the first commercial deployment in the Americas of its BroadSeis deghosting solution which was introduced at the Barcelona EAGE meeting in June 2010. The company said that the CGGVeritas Viking would be acquiring a 3000km2 3D survey with BroadSeis for Bahamas Petroleum off the southwest of the Bahamas. The full range of frequencies recorded by BroadSeis are expected to provide higher resolution imaging of Tertiary and Upper and Lower Cretaceous formations as well as helping to illuminate the deep Cretaceous-Jurassic reservoir targets which lie beneath the major thrust structures.

BroadSeis leverages the performance of the Sercel Sentinel solid streamer, which is recognized for its extremely low noise characteristics and can be deployed in configurations allowing the recording of an extra octave or more of low frequencies. Sentinel streamers are designed to record data while being towed at greater depths and are quieter than other streamers. The Sentinel advantages are combined with specific geometry configurations and data processing techniques. An example of conventional seismic data compared with BroadSeis can be seen in the illustration. According to the company, BroadSeis data has now been acquired in eight locations around the world, from Australia to the Arctic, in a range of water depths and geological basins.

Some say that these high-tech routes to deghosting taken by PGS and CGGVeritas illustrate a welcome technological differentiation and, among other things, deter any categorisation of geophysical service companies as mere commodity providers. To date the other significant players in marine seismic such as WesternGeco, Fugro and Polarcus have not specifically addressed the deghosting issue. What we do know is that WesternGeco is promising a revised version of its Q-Marine acquisition system although the timing is uncertain.

Comeback technology
One acknowledged technology comeback story spoken about in Vienna was the strong revival of interest in marine controlled source electromagnetic (CSEM) surveys led by Electromagnetic Geoservices (EMGS) which virtually has the field to itself. The company appears to have negotiated its way through a prolonged sticky patch when oil companies recoiled from the initial hype about the technology's capabilities as a helpful direct hydrocarbon indicator used in association with seismic data, especially in deepwater environments. In the last six months or so there have been a number of complimentary articles, one of special significance coming from Statoil which started the company off 10 years ago. The articles provide compelling evidence, based on numerous well results, that EM surveys have established a track record of predicting likely locations for successful drilling.

The turnaround in the company's fortunes was punctuated by last year's confidence boosting $150 million contract with Pemex. The work programme in the Mexican sector of the Gulf of Mexico consists of some 30 deep water 3D EM surveys. Data acquisition is being performed using the purpose-built 3D EM vessel BOA Thalassa, and new depth records for operations have been set during the ongoing contract. Other work seems to be coming in sufficiently for the company to charter a third vessel, Atlantic Guardian, in addition to its two purpose-built vessels. EMGS says that it has five months backlog for the vessel worth some $20 million.

Then there is the new joint industry partnership with Shell to look into next generation CSEM solutions to which another as yet unnamed major oil company has joined. It should be noted that Shell has commissioned nearly 100 EM surveys over the past eight years, so its apparent enthusiasm for the technology is based on experience at the sharp end.

On top of all this positive energy is the alliance with Fugro, agreed when the company's fortunes did not look as rosy as they do today. Part of the cooperation agreed two years ago involved a loan which Fugro has been able to convert into a near 15% of the company's outstanding shares. The move has of course prompted speculation about Fugro's ultimate intentions. A full takeover would not be a surprise from a company that has grown by acquisition of niche ‘geo' technologies where it can be the dominant player.

If Fugro was to make a bid any time soon, it would find itself with an almost unchallenged monopoly. Currently WesternGeco seems to be playing a waiting game and PGS is hoping to bring out a towed streamer EM acquisition technique, but the timeline is still uncertain and the industry will want quite a lot of convincing that it actually works.

That leaves OHM Surveys. This is the operations company that has surfaced in the revamp of the OHM Group including Rock Solid Images which came close to going under last year. The company is believed to be mobilising its OHM Leader vessel for work this summer, but will clearly take a while to become a potent competitor to EMGS. If Fugro executives are contemplating a bid, they probably should act sooner rather than later because on current trends EMGS is only going to become more expensive.

On the exhibition floor at EAGE Vienna it was hard to avoid the big booth statement being made by the newbie marine seismic company Dolphin Geophysical (‘G&G Notebook', OE June). Competitors seemed resigned to the inevitable impact on the market of an aggressive newcomer with its sights on becoming a major player in double quick time. Ten days after the EAGE meeting the Norwegian shipowning company Sanco announced it was ordering a new state-of-the-art 3D seismic vessel from Kleven Maritime in Norway with an option for a second vessel. Newbuilds like this are not what the business wants to hear about as it tries to absorb what is already seen as chronic over-capacity in the world fleet. However Sanco may have drawn the legitimate conclusion that there is a lot of older vessel inventory out there, and that oil companies will always take the new and shiny over a more experienced vessel. There has been no seismic contractor name attached to this latest construction, ie on the surface it is a spec build. However, plenty of people in the business are putting two and two together and surmising that the vessel will end up with Dolphin Geophysical, assuming it can continue to raise capital from its Norwegian investor base.

Gulf frustrations
The other frustration voiced last month by the marine seismic community was the continuing uncertainty over future seismic exploration surveys in the US Gulf of Mexico in the aftermath of Macondo. There are two issues currently muddying the waters. The government agency Bureau of Ocean Energy Management, Regulation & Enforcement (BOEMRE) continues to dither over its supplemental environmental impact statement (SEIS) required before any leasing in the western and central areas of the Gulf of Mexico can be conducted under the five year planning programme. No resolution is expected before the end of the year, leaving oil companies with little choice but to keep their pocket books closed with regard to spending on marine seismic ahead of leasing sales.

More ominously BOEMRE is currently handling a post-Macondo lawsuit which may directly affect seismic survey operations in the Gulf of Mexico. The Natural Resources Defense Council and other environmentalist organisations lobbying for more protection for ocean mammal life are challenging the adequacy of the environmental assessment performed in 2004 with respect to the conduct of seismic surveys in the Gulf of Mexico. They are challenging the Government's right to issue permits with respect to geophysical activities in the Gulf without additional environmental review and the imposition of additional limitations on the conduct of seismic operations. Rather than end up in court, BOEMRE is going for a negotiated settlement which is causing the marine seismic community grave concern. It fears that seemingly innocuous concessions could seriously jeopardise the market for seismic services in the Gulf of Mexico. For example, one demand is for the cessation of seismic surveys at night: if agreed, multi-client surveys, typical in the Gulf of Mexico, could be rendered unviable. There is talk of more exclusion zones and use of weaker seismic sources which would jeopardise surveys over salt bodies, one of the chief areas of exploration interest. The feeling is that BOEMRE wants to settle in order to avoid further public discussion, but this could be at considerable cost to the seismic business in the region.

Around the time of the EAGE meeting CGGVeritas announced that it had received a permit for a wide-azimuth multi-client seismic survey where it will also use its BroadSeis technology. The company said it was in discussion with a number of E&P companies regarding the final design of the programme scheduled for the fourth quarter of the year.

However, there has got to be a question mark over the realisation of this project. Both PGS and WesternGeco have similar projects in the making for the very good reason that these are high margin affairs. But it seems unlikely that oil companies will actually commit to financing such surveys until they know more about the government's intentions, while the contractors themselves will be cautious about proceeding until they know about any new government imposed limitations on their survey methods.

Ultimately no one can really believe that the US government will sanction too much further restriction on the search for oil and gas, given the country's enormous oil import bill. But putting the seismic business in the Gulf of Mexico back on track does not seem like a priority. Fortunately, with the price of oil well over the $100 mark, worldwide spending on seismic is providing adequate compensation. OE

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