Refining domestic crude oil: A path of great effort that continues to yield results 

SANTIAGO DE CUBA.— In 2024, Granma had already investigated the processing of heavy crude oil, which our country imported, using a solvent that brought it to 16 degrees API—created by a team of specialists at the Hermanos Díaz Oil Refinery—to convert it into medium crude and, once distilled, obtain the derivatives.
"That technological feat allowed our company to leave behind the period between 2016 and 2021, marked by losses, meager production, and the regrettable exodus of engineers, technicians, and service personnel," acknowledged engineer Irene Barbado Lucio, general director of this branch of the Cuban Petroleum Union (Cupet).
But in 2026, "the situation became extremely complex due to the energy blockade imposed by the Trump administration, preventing the oil we once purchased abroad from flowing through our facilities," the director lamented.
"Once again, the option was to become self-sufficient through our own efforts, as advised by the Commander-in-Chief in his concept of Revolution. He was the one who promoted the expansion and modernization of our plant in the 1980s, but I want to emphasize that it was designed to process light crude," specified Víctor Manuel Díaz Despaigne, director of the refining area.
THE BEGINNING OF THE TRANSFORMATIONS
When refining of imported heavy crude began, the Hermanos Díaz refinery—one of the country's four refineries—processed "naphtha, gasoline, fuel for drilling wells, fuel oil for thermoelectric power plants and distributed generation, as well as for asphalt production and the nickel industry," explained its CEO.

This was the result of the efforts of more than 700 workers, because the technological upgrades were numerous. Thanks to this collective ingenuity and the powerful movement of innovators and efficiency experts, profits were generated and distributed, and the emigration of skilled personnel to other Cupet companies and to centers in both the state and private sectors was prevented.
According to Barbado Lucio, "it was a complex process, involving much study and experimentation, in which our maintenance team—responsible, as its name indicates, for ensuring the operation of the industry—and Cupet's Refining Directorate also played a fundamental role."
"If at the end of the last decade we had resigned ourselves to the technological limitations that, obviously, made refining heavy crude impossible, the fate of this important industry would have been very uncertain. That is why, united, we overcame what seemed invincible," he affirmed.
With some seven decades of operation, work is underway at this site to improve infrastructure, production processes, and working conditions. In this regard, progress has been made on the flow measurement project to guarantee traceability of the processing, prevent fuel losses, and consequently strengthen fire suppression systems, lightning rods, and spill containment measures (which minimize environmental impacts in Santiago Bay).
ANOTHER TURNING POINT
Through coercion and blackmail, the U.S. government "dictated to our suppliers that they should no longer sell us crude oil. But the greatest risk was that the country would run out of naphtha, essential for continuing extraction in our oil wells," emphasized the member of the Party's Central Committee.
"If we were able to convert imported heavy crude into medium crude, given the urgency, we decided to do the same with domestic crude," stated the director of the refining area.
After intensive studies and adjustments, "we conducted an initial run of domestic crude in March; we obtained naphtha, diesel, and fuel oil, and, above all, the exploitation of our oil fields did not stop," the director pointed out.
Although these initial results were encouraging, the need for further adjustments to the plant also became apparent, given the viscosity and aggressiveness of Cuban oil due to its high sulfur and acidity levels.
That is why, in this initial stage, crude oil from the western region is being refined, as it "has better characteristics, flows better, and has lower viscosity," commented engineer Irenaldo Pérez Cardoso, deputy director of Cupet.
These actions were carried out in parallel with those developed by the Petroleum Research Center, based on thermoconversion, which were announced by the First Secretary of the Central Committee of the Party and President of the Republic, Miguel Díaz-Canel Bermúdez, along with members of the National Innovation Council.
According to the president, "we broke a precedent, a taboo that existed in the country, that national crude oil could not be used for other purposes, and we had practically condemned it to be used directly in a group of thermoelectric plants."
FOR GREATER AND BETTER RESULTS
Since the country has only received one Russian tanker in the last six months, Cupet continued working with domestic crude and processed 20,000 tons. Once again, the Hermanos Díaz team took on this colossal challenge, which happily "yielded results superior to the first run of this pilot phase, with the production of solvent naphtha destined for wells and fuel oil," said Irene Barbado Lucio.
Because the diesel obtained from domestic crude does not meet all the standards for commercialization, it was necessary to blend it with a higher-quality fuel to make it usable. The May run met the objectives; the extra-heavy fuel oil is even being used at the Antonio Maceo Thermoelectric Power Plant, with positive results, and its use in the nickel industry is being evaluated.
Even though the processed amount does not cover the country's demand, it represents a technological advancement for making more efficient use of endogenous energy resources. "Therefore, we reiterate that, given the high sulfur content, acidity, and viscosity of Cuban crude, specialists were required to perform calculations and adjustments to optimize and facilitate the refining process," stated Yanet Revé Luna, senior specialist in the Technology Department.
Thus, the crude oil washing systems were rehabilitated, "and the dosage of a new product called Vapen 220 pe was established. This product serves as a neutralizer at the top of the atmospheric distillation tower for the corrosive acids that form during the fractionation process," the specialist affirmed.
Taking into account the characteristics of Cuban oil, a line was constructed to collect the polluting gases released at the top of the vacuum distillation tower. These gases are then burned in the furnaces, thereby contributing to environmental protection and the health of the workers.
Since it was very difficult for the fuel to flow through the ten-inch diameter lines to reach the suction and processing unit, "we made an interconnection with a 20-inch line," Revé Luna noted.
And in complete accordance with the need to take a little bit away from the problems each day, this team—with many of its members working long hours and in complete anonymity—continues to apply science and innovation so that petroleum products—no longer imported, because they are denied to us—are present, to the extent possible, in the country's main activities.