The PGS Ramform Sovereign has already set numerous marine seismic records. (Image courtesy of PGS)

It’s hard to think of today’s oil prices as being “high,” but the fact is that until the banking crisis hit the US this fall, they were very high indeed, and few people anticipated the devastating impact a financial crisis would have on the price of a barrel of crude.

So most of 2008 was characterized by frenzied exploration spending as companies tried to keep their portfolios flush with new prospects. Geophysical contractors, eager to give their clients the best quality data in the shortest amount of time, stepped up to the plate and broke several records in the process.

Onshore

For years onshore seismic has seemed to be the poor stepchild of the seismic industry when it comes to innovation, but recent years have put that in the past. New technologies such as cableless land systems and new techniques such as slip-sweep acquisition are rendering better images than ever before.

CGGVeritas was awarded a large, ultra high-density high-resolution onshore seismic survey by Qatar Petroleum. The survey covers the Dukhan field in Qatar that extends under desert plains, coastal salt flats, transition zones, and shallow-water areas.

The company is providing the full range of acquisition and processing services, deploying a 40,000-channel seismic crew, 3-D vertical seismic profiling, and imaging services. This industry-first survey is expected to generate the highest possible resolution seismic image due to its volume, density, and technical requirements.

The company also has been awarded a multiyear contract for a similar survey in Oman.

ION Geophysical Corp. announced the recent completion of a multiclient seismic imaging project using its FireFly cableless land acquisition system, the first of its kind. The survey, shot in Colorado, encompassed about 30 sq miles (78 sq km) and employed more than 6,000 VectorSeis-enabled FireFly stations (Figure 1). Said Marty Williams of East Resources Inc., the primary underwriter for the survey, “We couldn’t have completed the project without FireFly.”

Land and marine

In February TGS-NOPEC announced that it was undertaking a major multiclient aeromagnetic study in Libya. The program will be acquired in several phases and will eventually provide data over all petroliferous basins in Libya. The initial phase includes more than 152,000 miles (250,000 km) of data to be acquired in a regional grid and will cover all of offshore Libya as well as several onshore basins.

Offshore

2008 may go down as the year 3-D electromagnetics (EM) became an industrial-scale exploration tool. The biggest 3-D EM breakthrough this year came in Norway. For the 20th license round EMGS acquired a 3-D EM project covering more than 3,475 sq miles (9,000 sq km) in the Barents Sea. At times as many as three vessels were used to acquire data at record production rates. The project was acquired using a 1.2- by 1.2-mile (3- by 3-km) grid. However, key lines over prospective structures were also acquired using a dense .4-mile (1-km) inline sampling to allow the application of inversion to create resistivity depth profiles (Figure 2). “What’s exciting about the Barents
Sea project is not just that it is the biggest 3-D EM survey ever acquired,” said Carl Hutchins, president of EMGS Multiclient Services.” The fact that this project was substantially prefunded speaks to the accelerating adoption of 3-D EM by the industry.”

EMGS also is performing an extensive multiclient EM scanning survey to search for commercial hydrocarbon deposits in the Krishna-Godavari basin, ahead of India’s 7th New Exploration Licensing Policy round (NELP 7). At 772 sq miles (2,000 sq km), the survey is the first of its kind.

PGS launched its latest Ramform vessel in April, the Ramform Sovereign (Figure 3). The boat was purpose-built to be able to tow more streamers and larger spreads, and already it has set several records.

The first record was set only a couple of months after launch. The vessel towed 17 streamers on a survey in the North Sea, the most streamers ever towed behind a single vessel. The next record, set offshore Norway, was for the widest spread. Fourteen streamers were spaced 330 ft (100 m) apart, for a total spread of almost a mile (1.3 km).

The final record was set offshore Brazil, where 14 4.9-mile (8.1-km) streamers were towed. “That’s the most streamer in the water ever,” said John Greenway, senior vice president of Marine Contract for PGS. “That’s 69 miles (113.4 km) of streamer.” He added that there were also more than 600 devices such as steerable streamer devices in the water.

The Ramform Sovereign is due to set another record in early 2009 when it tows 18 streamers on a survey offshore Brazil.

Wavefield Inseis also set a couple of “firsts” when it acquired surveys for BP. In July the Geowave Master undershot a survey around the Schiehallion floating production, storage, and offloading vessel using a new system of communication between vessels — a vessel-satellite-vessel link to eliminate line-of-sight issues, a high-bandwidth terrestrial radio link based on WiMAX technology to prioritize acquisition-critical traffic, and a low-bandwidth radio link to ensure communication at long range.

Another survey in the offshore Sirt Basin in Libya is one of the world’s largest proprietary narrow-azimuth 3-D marine surveys ever acquired, and BP confirms that it is the largest 3-D survey the company has ever acquired in terms of area. The survey, acquired with the Geowave Endeavour, is expected to take a year to complete.

Processing

Wavefield and its partner Geotrace completed one of the largest 3-D onboard processing projects for Marathon in the Makassar Straits offshore Indonesia.

The 1,158-sq mile (3,000-sq km) project was processed entirely on the vessel using a large compute facility and delivered to the client 10 days after the final shotpoint.
ION subsidiary GXT reported its largest processing job ever was awarded by Mobil Producing Nigeria Unlimited. The contract specifies that GXT and its Nigerian partner, Bulwark Services Ltd., will provide advanced imaging services for a series of 2-C and 4-C seabed surveys that will be acquired over the next several years.

Time-lapse

Nigeria’s first 4-D seismic acquisition in deepwater oil and gas operations was achieved at the SNEPCo-operated Bonga field, 73 miles (120 km) southwest of the Niger Delta. The 4-D seismic acquisition was achieved over a 76-day period, during which images of the subsurface were captured from one marine seismic acquisition vessel and three support vessels stationed in the field. The acquisition was carried out by a company based in Lagos, and the results will enable better well placements, resulting in maximization of Bonga field life-cycle production.

This is probably just a handful of the records that have fallen this year. In every case, E&P companies benefit from innovations that provide them with better images in less time.