Colombia made headlines in December when Petrobras and Ecopetrol announced results from Sirius-2, an appraisal well that confirmed the most significant gas discovery in the country’s history, a find projected to increase Colombia’s reserves by around 200 percent.
Sirius-2 is located in maritime block GUA-OFF-0, 31 kilometers off the Northern Caribbean coast and 77 kilometers from Santa Marta, capital of the Magdalena department. Drilling started in June 2024 at a water depth of 804 meters.
Significance of the Discovery
Antonio Velásquez, AAPG member and Ecopetrol offshore manager, said the discovery is significant for two primary reasons: materiality and distance from existing infrastructure.
“The Sirius-2 appraisal well proved nearly 6 (trillion cubic feet) of gas in place, while current Colombia’s total gas reserves are less than half that amount,” he said.
“Additionally, Sirius is located close to existing gas processing and transportation facilities connected to the Colombian market, a unique condition for a new deepwater discovery.”
Sylvia Anjos, AAPG member and exploration and production director at Petrobras, said Colombia exploration is part of the company’s 2025-29 Business plan, which outlines an investment forecast in exploration amounting to (U.S.) $7.9 billion from 2025 to 2029.
“Of this amount, $3.2 billion will be invested in Brazil’s Southern and Southeastern margins, $3 billion in the Equatorial Margin, and $1.7 billion in basins with foreign assets,” she said.
“Despite this significant investment in domestic assets, it is crucial to seek new exploratory opportunities in alignment with Petrobras strategy for oil and gas reserve replacement,” Anjos said.
She credited Petrobras with 71 years of exploratory success, and described how the company has spent the past 50 years refining its oil and gas operations in offshore Brazil and other countries, including Colombia.
“The Petrobras-Ecopetrol alliance has been crucial in achieving our current position,” she said. “Petrobras has maintained 39 years of continuous investment and activity in oil and gas projects in Colombia, with a particular focus on offshore ventures in the past two decades.”
Ecopetrol has a history in Brazil. The company opened an office in Rio de Janeiro in 2023 and has participated in the Pau Brasil and Saturno exploration projects. Ecopetrol has share of blocks in the Santos Basin and a 30 percent interest in the Gato de Mato discovery in Brazil’s Pre-Salt.
A New Phase
Velásquez spent three years working in the Ecopetrol Brasil office before returning to Bogotá and assuming the offshore exploration manager position in December 2022.
He said incorporating offshore projects into the portfolio represents an exciting phase for the company.
“The leap into the offshore universe has been challenging for Ecopetrol, which has traditionally been involved in Colombian onshore projects. However, passion and commitment of Ecopetrol’s professionals has fostered an accelerated learning curve that is already paying dividends,” he said.
“Ecopetrol self-prepared by progressively adding technical capabilities and corporate guidelines to adapt its talent and business ambition to offshore needs.”
While Ecopetrol has explored the offshore with multiple partners, including big deepwater players like Anadarko, Oxy, Shell and Repsol, the partnership with Petrobras has special significance, he said.
“Petrobras and Ecopetrol share the values and objectives of being prominent Latin American NOCs, which is the main reason why it is one of our partners of choice for deepwater endeavors,” he said.
“The collaboration has allowed the exchange of technical expertise and operational experience of Petrobras and the subsurface technical knowledge of Ecopetrol in the Colombian basins,” he said.
A High-Impact Initiative
For Anjos, Sirius represents more than just a discovery.
“The project embodies many years of collaborative effort, perseverance and, most importantly, multidisciplinary and multicultural teamwork,” she said. “All the stakeholders involved recognized this discovery as a high-impact initiative, and it truly is. The Sirius gas project positions Petrobras and Ecopetrol among the elite group of offshore gas field operators.”
The Sirius-2 well announcement came juxtapositioned with another announcement. Also in December 2024, Colombia was obligated to import natural gas for the first time in 40 years.
The somber milestone resulted from multiple factors. Production declines in the onshore Piedemonte area and offshore in Chuchupa-Ballena – fields that sustained natural gas production for five decades, were accompanied by increased demand for natural gas. The El Niño weather phenomenon arrived in 2024, severely depleting reservoirs, leading to water rationing measures in Bogotá and other cities that depend on hydroelectric power for energy. The country’s largest natural gas provider announced price increases of up to 35 percent in natural gas charges starting in February 2025.
Anjos said bringing Sirius online will help to avoid supply shortages in the future.
“This discovery, with an in-place gas volume exceeding 6 TCF, is comparable to the Chuchupa Field and has the potential to supply a portion of Colombia’s internal gas market demand. This could reduce reliance on imports, improve energy stability and foster economic and social development in the country,” she said.
“The discovery of Sirius gas is crucial for Colombia, confirming a substantial volume of natural gas that significantly enhances the country’s energy security,” she added.
The production project, involving four production wells with an innovative “subsea to shore” design, is expected to reach approximately 13 million cubic meters per day for 10 years.
The Petrobras-Ecopetrol consortium plans to invest $1.2 billion in the exploration phase and $2.9 billion in the production development phase, further contributing to the country’s social and economic development.
“The Sirius project is expected to generate around $3.94 billion in benefits for Colombia between 2029 and 2050, considering royalties, withholding from foreign suppliers, economic rights and income taxes,” Anjos said.
Challenges
Juan Carlos Mosquera, AAPG member and offshore manager for Petrobras Colombia, said operational success resulted from surmounting multiple operational and technical challenges.
“The Colombian Caribbean offshore basin is considered a frontier basin from an exploratory perspective, characterized by many geological models that have been tested and rejected over the years, leading to the ongoing development of technical knowledge,” he said. “This situation requires to the oil and gas companies to analyze every piece of data carefully and integrate it into their exploratory prospectivity models for the region.”
He noted that frontier basin poses challenges for investing companies, as they need to develop specialized services in the industry, particularly in the offshore sector.
Overcoming technical challenges is just the first step.
“Socio-environmental permitting challenges are significant, as Petrobras’ principles emphasize that respect for people and the environment is non-negotiable,” Mosquera said.
Velásquez agreed.
“The biggest challenge at this stage will undoubtedly be the social and environmental licensing of the project,” he said.
Social and environmental challenges are nothing new for Ecopetrol or for Colombia, whose internal conflict and strained relationships between communities and operators has impacted onshore oil and gas operations for decades.
The protests moved offshore in September last year when an order from a local judge in Santa Marta led to the suspension of all exploratory activity on the Tayrona block, home to the Sirius, formerly called Uchuva, well, and to local indigenous communities ruled by the Taganga Council. The order asserted that offshore operations would affect communities in the Sierra Nevada mountains and required consultation with local authorities to move forward.
After a series of negotiations with the ministries of Energy and Environment and the National Environment Licensing Authority, Ecopetrol proposed changing or removing references to “Uchuva” and “Tayrona” for the project and the Block, respectively, in the Colombian Caribbean.
Ecopetrol and Petrobras received approval from Colombia’s National Hydrocarbon Agency to use the names “Sirius” to refer to the project (formerly Uchuva) and “Gua-Off-0” for the Tayrona asset.
A Promising Future
Velásquez puts a positive spin on change from “Uchuva,” a Colombian fruit, to “Sirius,” the star in the Canis Major constellation that shines 25-times brighter than the sun.
“It is the most significant deepwater gas discovery ever made in the offshore Caribbean – the brightest star,” he said.
For Velásquez, Sirius lights the way to promising future for Colombia’s offshore industry.
“Sirius is just one of a large exploration portfolio with enormous potential that we have just unlocked,” he said. The offshore Caribbean has the potential not only to meet Colombia’s future gas needs, but also to enable the country to compete in the international LNG market,” he said.
Anjos said the Sirius project will provide tangible benefits to all Colombians.
“Petrobras’ operations in Colombia are deeply committed to socio-economic development. For the years 2024-25, the project’s social investments are projected to reach $2.9 million, focusing on strategic areas such as species and ecosystems conservation, payment for environmental services, fostering institutional relationships and promoting socio-economic development,” she said.
Next Steps
Anjos emphasized Petrobras’s long-term commitment to Colombia.
“Petrobras has maintained a continuous presence in Colombia for several decades and aims to sustain this presence through its O&G projects,” she said.
“Through its wholly owned subsidiary PIB-COL and in partnership with Ecopetrol, Petrobras has made significant progress in exploration, with the expectation that the Sirius Project will progress from the evaluation phase to natural gas production over the coming decades. The consortium will continue conducting essential studies to advance with the Appraisal Plan and the production development project,” she added.
The project involves a range of technical and operational activities, including installation of infrastructure for gas transportation and production systems on the seabed and obtaining the necessary environmental licenses.
Companies expect first gas production to commence three years after receiving all environmental licenses.
In addition to the Sirius discovery, Petrobras and Ecopetrol will continue exploration activities, drilling additional exploration and appraisal wells to evaluate other opportunities identified in Block Gua-Off-0.
The Role of Geoscientists in Offshore Discoveries
The Sirius project benefits from the hard work of geoscientists and AAPG members, including Velásquez, who has supported multiple AAPG events and educational programs over the past decade and Juan Mosquera, Petrobras exploration manager, who is a frequent participant in AAPG events.
Anjos was vice president of AAPG’s Latin America and Caribbean Region from 2015-17 and currently serves as general chair of the AAPG International Conference and Exhibition 2025 taking place in Rio de Janeiro Sept. 30-Oct. 3.
Anjos said geoscientists are the keystone to the success of offshore oil and gas exploration projects, particularly in frontier basins.
“Geoscientists working in frontier exploration activities require open-minded optimism and no fear of facing risks, along with a robust theoretical geological and geophysical foundation while keeping pace with advanced technical and technological tools,” she said. “This combination allows them to effectively integrate available data and information, develop reliable models, and continuously enhance and consolidate their expertise in areas of exploratory opportunities investigation.”
She noted that specialized training in seismic interpretation, AVO (amplitude versus offset) analysis, and natural gas geochemistry is crucial for geoscientists involved in exploratory projects like the Sirius discovery. This expertise empowers them to deliver critical interpretation that enhances business activities related to geoscience.
“Different scenarios are built and evaluated and hypotheses checked to evaluate risks and opportunities. Each new data acquired is vital for validating and refining geological and geophysical models to understanding deep water siliciclastic system,” she said. “Geoscientists’ contributions are not just important; they are foundational to making informed decisions that drive exploration success in the oil and gas industry in deep waters of frontier basins.”
Velásquez credits Ecopetrol and Petrobras geoscientists with laying the groundwork for the Sirius success.
“As with every game-changing discovery, geoscientists have played a key role, bringing knowledge, talent, diligence, perseverance, passion and creativity,” he said.
“Long before recent major discoveries such as Sirius, Gorgon or Glaucus, geologists and geophysicists were able to manage geological knowledge acquired over decades of exploration in the offshore Caribbean, to improve exploration performance that has led to a remarkable increase in exploration performance, achieving a record success rate of over 50 percent in this frontier basin.”
The Role of Professional Associations
He encouraged fellow geoscientists join AAPG and other societies that provide both technical training and professional development opportunities.
“Professional associations provide vital spaces for technical learning, science promotion and exchange, networking and leadership. All the dimensions you need to succeed in your career,” he said.
Mosquera said AAPG and other professional associations play a vital role in the oil and gas industry by documenting and promoting the evolution of geosciences through various channels.
“Associations facilitate platforms for sharing technical information and organize congresses and training programs specifically designed for geoscientists,” he said. “These initiatives are aimed at fostering integration and advancing expertise within the field, ensuring that geoscientists are well-equipped to meet the challenges of the industry.”
Mosquera said oil and gas exploration is a great option for geoscientists who want to make a meaningful impact on communities.
“I encourage the geoscience community to persevere in this rewarding and multifaceted profession, which offers the industry opportunities that translate into meaningful contributions to society and the environment,“ he said.
Velasquez has advice for students and young professionals who are considering careers in the energy industry.
“Find a balance between what you are passionate about and what you are good at; your skills and desires all working towards the same goal. This makes you unique, motivates you and helps you persevere when the challenges you face seem out of reach,” he said.
The world benefits when geoscientists, and explorers, find their passion.
“Thanks to the perseverance of explorers, Colombia is now dreaming of offshore gas,” he said. “The promising potential reflected in these recent successes should focus industry attention on this new world-class energy frontier.”
Sharing the Discovery
Petrobras and Ecopetrol will discuss the Sirus-2 discovery as a part of the 30th AAPG Discovery Thinking Forum taking place at the International Meeting for Applied Geoscience and Energy in Houston on August 27.
To learn more and to register, visit ImageEvent.org.