OREANDA-NEWS. Brazil's state-controlled Petrobras and its partners, Portugal's Galp and Brazilian independents QGEP and Barra, have made another light oil discovery in the Santos basin's Carcar? field, which is now being called one of the most significant subsalt discoveries in Brazil.

The Carcar? NW well, 3-SPS-104DA, confirmed the presence of a 320m (1,049ft) column of 31? API crude, a continuity of an accumulation identified in the Carcar? N well early this year. The field is located in the BM-S-8 block of the prolific Santos basin.

"It is also extremely significant that the pre-salt limestone reservoirs in the Carcar? NW well are in the same pressure gradient of those in the two other wells, indicating the reservoir communication across different structural compartments," Barra said in a statement.

Carcar? could have as much oil as the 8bn-12bn bl Lula subsalt field in the same basin, according to Petrobras.

The consortium will drill an exploration well at the Guanxuma prospect elsewhere in the BM-S-8 block in 2016.

Petrobras operates the block with a 66pc stake. Galp holds 14pc, and QGEP and Barra each hold 10pc.

Earlier this year, the BM-S-8 consortium requested and obtained from Brazilian oil regulator ANP an extension of the appraisal period in Carcar? up to March 2018 in order to gather additional information from the reservoir and better support the definition of the future development plan.

The field was originally expected to draw first oil in 2018, according to Petrobras' 2014-18 business plan, but is now only expected to start after 2020, according to the company's recent $130.3bn 2015-19 plan.