G E O S C I E N C E S Sarah Parker Musarra • Houston
GoM surveys heat up
The waters of the Gulf of Mexico are once again seeing major
seismic surveying activity. TGS and Schlumberger recently started
the full-azimuth multi-client Revolution XII and XIII surveys.
The surveys will cover approximately 7,150 sq km ( 2,761 sq mi)
in the Green Canyon, Atwater Valley, and Ewing Bank protraction
areas of the central Gulf of Mexico.
They will be acquired using the Schlumberger WesternGeco Q-Ma-
rine point-receiver marine seismic system combined with the propri-
etary multi-vessel, Dual Coil Shooting acquisition technique. This will
provide broadband, long-offset, full-azimuth data. This combination of
technology and technique, the companies claim, will improve illumina-
tion and imaging of the subsalt and other complex geologic features.
The two companies have a history of cooperation in the Gulf of
Mexico, starting in 2008 with acquisition of the Freedom WAZ sur-
vey followed later by the Liberty WAZ and Patriot M-WAZ surveys.
These new Revolution Dual Coil Shooting full-azimuth surveys
will record offsets of more than 14 km ( 9 mi) for imaging below the
salt in the deepwater Gulf of Mexico.
Also, autonomous marine vehicles (AMV) are being deployed.
These AMVs will simultaneously acquire ultra-long offsets of more
than 20 km ( 12 mi), which benefit full waveform inversion in the
accurate velocity model building over such complex subsalt areas.
Maurice Nessim, president of WesternGeco, added: “With these
new techniques, we expect to see further improvements in subsalt
imaging and amplitude fidelity for reservoir characterization providing value for our customers.”
Elsewhere in the Gulf, TGS also recently updated on its progress
in the acquisition of its Gigante 2D survey, a 186,000-km (115,575-
mi) regional 2D seismic survey covering areas in Mexico’s proposed
license rounds in the Perdido, Campeche, and Mexican Ridges regions. TGS will also perform line ties to its previously acquired US
Gulf of Mexico regional grids.
As of early August, the program has acquired more than 160,000
km (99,419 mi) of 2D data and almost 150,000 km (93,205 mi) of fast-track data has already been delivered to clients.
In parallel, TGS is acquiring the Gigante multi-beam, coring and
geochemical survey over a 600,000-sq km (231,661-sq mi) area.
The company increased the multi-beam fleet to two vessels during 2Q with coring operations continuing from a third vessel. By
mid-year more than 50% of the data was in with the remainder of the
project expected to be complete in 4Q.
Interpreted results will be integrated with the 2D seismic survey.
Both surveys are supported by industry funding.
COSL completes survey jobs
China Oilfield Services Ltd. (COSL) recently completed two jobs,
in the Far East and the Barents Sea.
Faced with the persistent low oil price, while meeting demand
for oil and gas exploration and development in domestic waters in
China, COSL said it has been accelerating its strategy to actively
compete in the international oilfield service market. It is now deriving 40% of its revenue from overseas.
The 12-streamer vessel HYSY 720 completed an operation in the
Barents Sea, more than 900 km (559 mi) above the Arctic Circle.
COSL said the survey was noteworthy for several reasons. It is said to
be China’s first attempt in performing 3D seismic data collection in ultra-high latitude and ultra-low-temperature waters. The company also
claimed it recorded a new monthly seismic data acquisition record of
1,820.58 sq km (703 sq mi), saying this was also a record in China.
The operation lasted for 100 days and concluded in August. The
environment was very complicated, with sea water mostly frozen,
There is only a short window of four to five months in a year for
operations in the Arctic waters, COSL said. The crew implemented
a round-the-clock operation routine and tackled the impact on team
members from the prolonged daylight.
In addition, HYSY 720 is the first deepwater seismic vessel propri-
etarily built in China, the company claims. COSL said it is “the first
12-streamer dual-source large-scale seismic vessel in China driven
by diesel-electric propulsion system capable of sailing to Class 1 un-
limited navigation zone around the world.”
COSL also completed its first exploration operation in the Far East,
finishing a 3D seismic acquisition survey first announced in June.
“The operation situation was complicated, including the complex
fishery and year-round foggy weather. Also, operating in the shallow-water zone is a threat to the under water equipment,” COSL said.
To counteract these challenges, the company said it created what
it called a “seamless solution:” preparing protection measures for
the equipment according to weather and tidal cycles to lower the
operation risks. COSL used the Hai Yang Shi You 718 (HYSY 718) to
complete the Far East campaign.
Europa: Potential in Padraig
Europa Oil & Gas claims its recently awarded three-year licensing option (LO) 16/22 offshore western Ireland could hold 300-600
MMboe of resources. The concession covers 992 sq km (383 sq mi)
in the Padraig basin. Following the completion of a work program,
Europa has the option to apply to the Irish authorities for conversion
to a full frontier exploration license (FEL).
The company plans to further mature the prospect inventory and
will seek a farm-in partner for the FEL conversion and in due course
drill an exploration well, subject to a positive technical and commercial outcome from a 2D seismic reprocessing campaign.
LO 16/22 is on the eastern margin of the Rockall basin and contains numerous exploration leads in water depths of 800-2,000 m
( 2,624-6,562 ft). It is 300 km (186 mi) west of Ireland and 150 km (93
mi) west of the Spanish Point and Burren discoveries.
The Pre-rift oil play comprises Lower and Middle Jurassic sandstone reservoirs in large tilted fault block structures with Jurassic
source rocks, with further potential for a Triassic gas play. •
The 12-streamer vessel HYSY 720 just completed a 3D seismic survey in
the Arctic Circle, said to be China’s first attempt in collecting 3D seismic
data in ultra-high latitude and ultra-low-temperature waters. (Photo courtesy COSL)