In response to the high potential of the presalt section in the basin and the success of its original Cluster survey, the company is now acquiring a new 6,178-sq-mile (16,000-sq-km) “Cluster Extension” survey (pink areas on map).
In light of recent discoveries announced in the “Cluster” blocks offshore Brazil, the petroleum industry is seriously reexamining the geology of the Santos Basin.

Multiclient prestack time-migrated (PSTM) data acquired and imaged by CGGVeritas in the deepwater Santos Basin, known as the “Cluster” survey (yellow areas on map), led to the Tupi, Jupiter, and Carioca discoveries, along with numerous others in the presalt sediments.

Due to the geological complexity of this area, the Cluster survey was reprocessed into depth to help E&P companies better analyze, understand, and quantify the petroleum system in the Santos presalt section. Technologies such as controlled-beam migration, reverse-time migration, and 3-D tomography were used to build the models. As a result of this reprocessing, 8,880 sq miles (23,000 sq km) of prestack depth-migrated (PSDM) data have just been made available to the industry.

Prior to the delivery of the final PSDM products from the Cluster survey, preliminary work began to reveal previously unseen details that are changing the industry’s understanding of the evolution of the Santos Basin. Using the base-of-salt surface required in the depth migration, a second, deeper surface within the presalt section was constructed to delineate the presalt structural grain.

“The structural fabric now visible in the presalt stratigraphy is significantly different from what would be predicted from bathymetric or top-salt structural patterns,” said Dr. Carl Fiduk, chief geologist for CGGVeritas in the Americas.

“Identification and mapping of this structural fabric will be a critical part of future successful exploration efforts. By significantly enhancing the image of the reservoir interval beneath the evaporite section, we expect these high-quality depth data to help companies reduce their exploration risk in the Santos Basin.”

In response to the high potential of the presalt section in the basin and the success of its original Cluster survey, the company is now acquiring a new 6,178-sq-mile (16,000-sq-km) “Cluster Extension” survey (pink areas on map). The survey is being acquired in six swaths over open acreage to the south of the original survey. Swaths three and four (outlined in green on the map) are expected to be finalized, with fast-track PSTM, and available to the industry by Q3 2009. The acquisition of all six swaths is slated for completion by March 2010 and will be processed directly to depth.

This extension has already attracted numerous E&P companies eager to be involved in the area. The expanded survey will potentially reveal the extent of newly imaged structural patterns in the presalt stratigraphy. Final deliverables offered for the Cluster Extension include fast-track PSTM after each swath, controlled-beam migration PSDM, Kirchhoff PSDM, and reverse-time migration PSDM. These deliverables will be merged with the PSDM products of the original Cluster survey, creating 14,670 sq miles (38,000 sq km) of depth volumes.

“We launched our Cluster Extension in response to the current, intense industry interest in the Santos Basin offshore Brazil and in anticipation of the next big presalt discovery,” said Luc Schlumberger, executive vice president for the Latin America region at CGGVeritas. “The Tupi, Jupiter, and Carioca discoveries found within our Cluster survey heightened attraction to the area and to both our Cluster and Cluster Extension surveys.

“We are committed to ensuring that our clients have the most advanced tools at their disposal to increase their chances of finding the next Tupi.”