Tall City Exploration Funding, Investors & Competitors

Saudi Aramco is the national oil company of Saudi Arabia and holds the exclusive right to explore for, produce, and refine the country’s hydrocarbons. It is the largest oil and gas producer in the world with a production volume of 12.4 mmboe/d in 2024, including 10.8 mmboe/d of liquids. Its 4.1 mmb/d in net refining capacity makes it the world’s fourth-largest refiner. It also owns 57.6 million metric tons of chemical manufacturing capacity, placing it among the top five global chemical companies.

ExxonMobil is an integrated oil and gas company that explores for, produces, and refines oil worldwide. In 2025, it produced 3.3 million barrels of liquids and 8.4 billion cubic feet of natural gas per day. At the end of 2025, reserves were 19.3 billion barrels of oil equivalent, 69% of which were liquids. The company is one of the world's largest refiners, with a total global refining capacity of 4.1 million barrels of oil per day, and is one of the world's largest manufacturers of commodity and specialty chemicals.

Chevron is an integrated energy company with exploration, production, and refining operations worldwide. It is the second-largest oil company in the United States with production of 3.0 million of barrels of oil equivalent a day, including 7.7 million cubic feet a day of natural gas and 1.7 million of barrels of liquids a day. Production activities take place in North America, South America, Europe, Africa, Asia, and Australia. Its refineries are in the US and Asia for total refining capacity of 1.8 million barrels of oil a day. Proven reserves at year-end 2024 stood at 9.8 billion barrels of oil equivalent, including 5.1 billion barrels of liquids and 28.4 trillion cubic feet of natural gas.

PetroChina, the national champion that inherited the majority of Chinese onshore oil and gas assets, has developed into an international supermajor. In 2024, it produced more than 1.7 billion barrels of oil equivalent of oil and gas, and processed 1.4 billion barrels of crude oil. It also has more than 22,000 service stations. The fluctuations in the prices of crude oil, refined products, chemical products, and natural gas have a significant impact on PetroChina’s revenue. State-owned China National Petroleum Corp is PetroChina’s controlling shareholder with a stake of more than 82%.

Shell is an integrated oil and gas company that explores for, produces, and refines oil around the world. In 2024, it produced 1.5 million barrels of liquids and 7.7 billion cubic feet of natural gas per day. At year-end 2024, reserves stood at 9.6 billion barrels of oil equivalent, 48% of which consisted of liquids. Its production and reserves are in Europe, Asia, Oceania, Africa, and North and South America. The company operates refineries with a capacity of 1.6 mmb/d located in the Americas, Asia, and Europe, and sells about 12 million tons per year of chemicals. Its largest chemical plants, often integrated with its local refineries, are in Central Europe, China, Singapore, and North America.

TotalEnergies is an integrated oil and gas company that explores for, produces, and refines oil around the world. In 2024, it produced 1.5 million barrels of liquids and 5.2 billion cubic feet of natural gas per day. At the end of 2024, reserves stood at 11.1 billion barrels of oil equivalent, 54% of which are liquids. During 2024, it had LNG sales of 39.8 million metric tons. The company owns interests in refineries with a capacity of nearly 1.8 million barrels a day, primarily in Europe, distributes refined products in 65 countries, and manufactures commodity and specialty chemicals. At year-end, its gross installed renewable power generation capacity was 26 gigawatts.

Reliance Industries Ltd is engaged in hydrocarbon exploration and production, refining and marketing, petrochemicals, financial services, retail, and communications. The Group has five principal operating and reporting segments: Oil to Chemicals (O2C), Oil and Gas, Retail, Digital Services, and other services. Reliance's refineries produce a range of petroleum products that find use as fuel variants, feedstock, and fuel for power and cement plants. Fuels produced in refineries are exported to several countries and can be processed into any grade of gasoline or diesel. The Oil to Chemicals segment, which derives the majority of revenue, includes Refining, Petrochemicals, fuel retailing through Reliance BP Mobility Limited, aviation fuel, and bulk wholesale marketing.

ConocoPhillips is a US-based independent exploration and production firm. Its operations are primarily in Alaska and the Lower 48, with footprints in Canada, Europe, Asia-Pacific, the Middle East, and Africa. It also has substantial integrated LNG production and marketing activities across geographies.

CNOOC is China's main offshore oil and gas exploration and production company. Through its parent company, it has exclusive rights to partner with foreign companies in offshore China projects. Net production for 2024 reached 726.8 million barrels of oil equivalent (78.0% oil), and year-end proven reserves were 7.27 billion barrels of oil equivalent. Assets outside China make up around 32.2% of production.

China Shenhua Energy Co Ltd is a globally integrated coal-based energy company, mainly engaging in business segments: Coal, Power generation, Shipping, railway, port, and Coal chemical. Focusing on its core coal mining operation, China Shenhua leverages its self-developed transportation and sales network as well as downstream power plants, coal-to-chemicals facilities, and new energy projects to achieve cross-sector and cross-industry integrated development and operation.

Petrobras is a Brazil-based integrated energy company controlled by the Brazilian government. The company focuses on exploration and production of oil and gas in Brazilian offshore fields. Production in 2024 was 2.7 million barrels of oil equivalent a day (80% oil production), and reserves stood at 11.4 billion boe (85% oil). At end-2024, Petrobras operated 10 refineries in Brazil with capacity of 1.8 million barrels a day and distributes refined products and natural gas throughout Brazil.

Valero Energy is one of the largest independent refiners in the United States. It operates 15 refineries, with a total throughput capacity of 3.2 million barrels a day in the US, Canada, and the United Kingdom. Valero also owns 12 ethanol plants with capacity of 1.6 billion gallons a year and holds a 50% stake in Diamond Green Diesel, which can produce 1.2 billion gallons per year of renewable diesel.

Marathon Petroleum is an independent refiner with 13 refineries in the mid continent, West Coast, and Gulf Coast of the United States with total throughput capacity of 3.0 million barrels per day. Its Dickinson, North Dakota, facility produces 184 million gallons a year of renewable diesel. Its Martinez, California, facility has the ability to produce 730 million gallons a year of renewable diesel. The firm also owns and operates midstream assets primarily through its listed master limited partnership, MPLX.

BP is an integrated oil and gas company that explores for, produces, and refines oil around the world. In 2024, it produced 1.2 million barrels of liquids and 6.9 billion cubic feet of natural gas per day. At the end of 2024, reserves stood at 6.2 billion barrels of oil equivalent, 59% of which are liquids. The company operates refineries with a capacity of 1.6 million barrels of oil per day.

Repsol Upstream is the exploration and production division of Repsol S.A., concentrating on discovering and extracting oil and natural gas reserves worldwide. Headquartered in Madrid, Spain, it manages assets across more than 15 countries including Brazil, Venezuela, Libya, and the North Sea. Repsol Upstream produced 389,000 barrels of oil equivalent per day in 2023, with significant operations in the Eagle Ford shale in Texas and the Peru LNG project. The division partners with companies like YPF in Argentina and focuses on deepwater developments off the coast of Colombia.

Cepsa is a Spanish integrated energy group that refines crude oil, sells fuels through its own service-station network and manufactures petrochemicals including phenol, acetone and linear alkylbenzene. Refining is concentrated in Andalusia, at Huelva and San Roque, and the group also holds upstream oil and gas interests outside Spain. More recent capital spending has shifted toward renewable hydrogen, biofuels and electric-vehicle charging, and the group adopted the Moeve brand in 2024. Abu Dhabi's Mubadala has been the controlling shareholder since 2011.

QGC is an Australia-based natural gas company focused on coal seam gas exploration and production in the Surat and Bowen Basins of Queensland. The firm operates 16 pilot wells and extensive appraisal programs supplying gas to domestic power stations and the Curtis Island LNG export facility near Gladstone. QGC processes raw gas through compression and treatment plants before pipeline transmission, converting reserves into liquefied natural gas for markets in Asia. Acquired by Shell in 2009, it contributes significantly to Queensland's energy sector with over 1,500 production wells developed.

Hyundai Oilbank is a Seoul-headquartered petroleum refiner in South Korea. The company operates the Daesan refinery complex, producing gasoline, diesel, jet fuel, lubricants, and petrochemicals like benzene and paraxylene. It supplies fuel to domestic automotive, aviation, and industrial sectors while exporting refined products to Asia and the United States. Hyundai Oilbank invests in clean fuel technologies, including low-sulfur marine fuels and renewable diesel blends.