Petrobras will carry out a formation test on its ultra-deepwater Iara presalt discovery in the Santos basin offshore Brazil after hitting a 310-m (1,017-ft) hydrocarbon column.

The company said in a press release it had completed the drilling of the fifth exploration well in Block BM-S-11, which contains Iara. Well 3-RJS-715D (3-BRSA-1181D-RJS), informally known as Iara Alto Ângulo (Iara High Angle), is located 225 km (140 miles) off the coast of Rio de Janeiro in a water depth of 2,128 m (6,982 ft). The well was drilled in the central area of the concession’s discovery evaluation plan, around 4 km (2.5 miles) to the north of the original Iara discovery well 1-RJS-656 (1-BRSA-618).

The latest appraisal was designed and executed with a subhorizontal geometry and reached a total depth of 6,672 m (21,891 ft), after drilling approximately 900 m (2,953 ft) of carbonate rock below the salt layer. Petrobras said in the release a 310-m hydrocarbon column was identified, with the reservoir featuring characteristics similar to those found in the original Iara discovery well, which was drilled vertically and where good-quality oil was identified (28ºAPI).

Given the geometry used in the well, a formation test will be conducted at the location to evaluate the productivity of the oil-bearing reservoirs, the company added. The consortium will proceed with the activities outlined in the evaluation plan approved by the National Petroleum, Natural Gas, and Biofuels Agency (ANP).
Petrobras is the operator of the consortium (65%) in partnership with BG E&P Brasil (25%) and Petrogal Brasil (10%).