Petrobras Morpho Samples Test at 35 to 40 API, Matching Guyana Crude Quality

Preliminary analysis of samples from the Morpho well in the Foz do Amazonas basin points to crude with an API gravity between 35 and 40, a light grade whose quality is described as similar to oil produced in Guyana. Petrobras identified the light oil at Morpho and has begun analysing the characteristics of the crude found off the coast of Amapa state.

API gravity is the measure used worldwide to determine the density of crude. Oil in the 35 to 40 band commands a higher commercial value because it requires less complex refining processes. The material found at Morpho is compared to light crudes, which carry a higher market value since they are easier to refine and process.

An industry source with knowledge of the tests run by the state-controlled company said the Morpho samples indicate good quality oil, classed as light by industry standards. The samples are undergoing detailed evaluation at the Petrobras research centre, Cenpes, in Rio de Janeiro, to confirm the physical and chemical properties of the find. The final result of those analyses is due in the coming weeks, according to Cidade091.

For traders reading the equatorial margin, the quality read is the variable that matters. Brasil em Folhas reported that the characteristic of the crude identified in the Amapa region is similar to that found in Guyanese deposits. That comparison sets the reference point for how a future Foz do Amazonas barrel would be positioned against an established light sweet stream already moving into Atlantic basin refining systems.

The discovery follows Petrobras's official announcement of the presence of hydrocarbons in the Foz do Amazonas basin. The company had confirmed the oil discovery at the Morpho well on August 21.

Drilling activity is set to widen. Ibama authorised three further wells in block FZA-M-59 in response to the results. Exploration in the Foz do Amazonas is treated as a new frontier for the state company, though advancing to commercial scale depends on strict environmental licensing.

President Luiz Inacio Lula da Silva highlighted the potential of the discovery during a visit to Amapa state.

The reporting sits across several outlets. Brasil em Folhas published its account under the byline of Carla Fernandes, with a last update timestamped September 5, 2026 at 04:30. Daily Journal published on September 6 at 09:01, citing InfoMoney coverage from the same day at 08:52. Cidade091 carried its explainer under the byline of Lucas Contente, published September 6, 2026 at 17:50.

Until Cenpes returns confirmed physico-chemical properties, the 35 to 40 API figure remains a preliminary reading. It is the number that will determine where a Foz do Amazonas barrel prices relative to the Guyanese benchmark it is being measured against.