Petroleum Refineries (United States) — NAICS 324110

An investor's primer. Figures are U.S.-specific unless noted. Reported facts are cited; forward-looking statements are labeled in the wording as judgments or outlooks.

1. Overview

Petroleum refineries take crude oil and turn it into the fuels and feedstocks a modern economy runs on: gasoline, diesel, jet fuel, heating oil, asphalt, and the building blocks for plastics and chemicals. It is a capital-intensive, cyclical, commodity-processing business — a refinery is a multibillion-dollar chemical plant that profits from the spread between what it pays for crude and what it earns selling refined products, not from the price of oil itself.

Why an investor cares: refining is one of the most cash-generative — and most volatile — links in the energy chain. Margins can swing from record profits (2022) to outright losses (2020) within a couple of years, and the survivors return enormous amounts of cash to owners through dividends and buybacks. It is also a structurally shrinking U.S. industry: no major new refinery with significant downstream conversion capacity has been built since Marathon's 1977 Garyville plant (though a 45,000-barrel-per-day Galveston refinery began operating in 2022). [23] Capacity is closing faster than it is added, and long-term gasoline demand faces pressure from vehicle efficiency and electric vehicles (EVs). That combination — tight, shrinking supply against still-large demand — is the central investment debate.

• Public-market ways in: shares of independent refiners such as Marathon Petroleum, Valero, and Phillips 66, or diversified exposure through the integrated majors (ExxonMobil, Chevron) that run refining as one segment. [17][4]
• Private ways in: direct refinery ownership is the province of foreign national oil companies (Saudi Aramco's Motiva), private conglomerates (Koch's Flint Hills Resources), and institutional buyers of distressed assets (the 2025 Citgo auction). This is not a retail-accessible private market. [15][16][24]

2. What it is, and how it's structured

Scope (NAICS 324110): establishments primarily engaged in refining crude petroleum into refined petroleum products — gasoline, distillate (diesel/heating oil), jet fuel/kerosene, residual fuel oil, lubricant base stocks, asphalt, LPG, petroleum coke, waxes, solvents, and petrochemical feedstocks — through processes such as fractionation, straight distillation, and cracking. [25]

What it excludes (adjacent NAICS codes):

• 211120 — Crude Petroleum Extraction: pumping oil out of the ground (upstream). Refining is "downstream."
• 325110 — Petrochemical Manufacturing: making ethylene, propylene, benzene, etc. Many refineries are integrated with petrochemical plants next door, but the chemical units are a separate code.
• 324121/324122 — Asphalt paving and roofing; 324191 — Lubricating oils and greases; 324199 — Other petroleum & coal products: downstream product manufacturing that buys refinery output.
• 486110 / 486910 — Pipeline transportation of crude oil / refined products and 424710 — Petroleum bulk stations & terminals: the "midstream" that moves and stores the barrels.
• 457110 — Gasoline stations with convenience stores: fuel retail. Some refiners (Marathon, Phillips 66) also own marketing/retail networks, but the pump is a different code.

How a refinery works: A refinery is a continuous-process conversion plant. Atmospheric distillation first separates heated crude into fractions by boiling point. Vacuum distillation processes the heavier residue. Conversion units — fluid catalytic crackers, hydrocrackers, cokers, reformers, and alkylation units — turn lower-value streams into gasoline, distillate, jet fuel, and blending components. Hydrotreaters remove sulfur; hydrogen plants, sulfur-recovery units, utilities, storage tanks, and wastewater systems support the process. Products are blended to seasonal and regional specifications before leaving by pipeline, vessel, rail, or truck. [26]

Joint products and limited flexibility: Refineries cannot freely choose to make only the highest-margin product. Gasoline, diesel, jet fuel, coke, gases, and residual streams are joint outputs, and the ability to alter yields is limited by crude type and equipment. Even when diesel's wholesale price exceeded gasoline's by about $0.50 per gallon in 2022, the industry's diesel yield moved only from 29.7% to 30.3%. [27]

Ownership mix: unusually concentrated for a manufacturing industry. A handful of owners control most capacity, and they come in three flavors: (1) publicly traded pure-play/independent refiners; (2) publicly traded integrated majors where refining is one division; and (3) private and foreign-owned operators. The largest single U.S. refinery — Motiva's Port Arthur, Texas plant — has EIA calendar-day capacity of approximately 654,000–656,400 barrels per day, though Motiva describes total throughput capability of 730,000 barrels per day (a different measure). [15][28] It is owned by Saudi Aramco, not a U.S. public company.

3. How big it is

Our federal statistics (U.S. Census Bureau / SBA):

How to read these numbers. This is a small-headcount, enormous-revenue industry: about 55,000 workers but $825 billion in shipments in 2022 — roughly $15 million of output per employee, reflecting extreme capital intensity. The concentration figures confirm it: just four firms account for 52% of receipts and twenty firms for 95%. The HHI of 853 sits below the 1,500 threshold the antitrust agencies treat as "moderately concentrated," but the top-heavy CR4 tells the real story.

Important caveats:

• The receipts figure is price-inflated. 2022 was a record-high year for crude prices and refining margins, so $825 billion overstates a "normal" year. Revenue in this industry rises and falls with oil prices and is not a stable gauge of profitability or physical size. Shipment value is not economic value added — petroleum-refinery sales can surge merely because crude and products become more expensive, even as per-barrel margins contract.
• Federal business statistics do not materially undercount this industry — it is dominated by large corporate establishments that Census captures well. This is the opposite of industries dominated by tiny operators. The "50 firms" is genuinely close to the real number of distinct refining companies.
• But ownership is partly invisible in these counts. Several refineries belong to integrated majors (ExxonMobil, Chevron) whose primary classification is not refining, and to foreign/state owners (Saudi Aramco) and private firms (Koch). So the pure-play public "refining sector" an investor sees on a stock screener is only part of the picture.
• Establishment vs. refinery counts differ. Census counts 143 establishments (2023) [1]; the Energy Information Administration (EIA) counts 130 operable refineries (128 operating, 2 idle) as of January 1, 2026 [4]. The gap reflects different definitions (Census includes some non-production and administrative units; EIA counts physical operable plants). EIA's universe also includes some nontraditional processing facilities — its 2025 report, for example, included an alkylate-only facility without a traditional crude-distillation column. [29]

Physical scale (EIA operating data): U.S. operable atmospheric distillation capacity was 18.160 million barrels per calendar day across 130 operable refineries on January 1, 2026 — down from 18.423 million b/cd and 132 refineries a year earlier. [4][30] Calendar-day capacity incorporates normal planned and unplanned downtime; stream-day capacity (assuming optimal full operation) was 19.157 million barrels per day. [30] Refineries run hard when margins justify it: full-year utilization averaged about 90.6% in 2024 and rose to 92.0% in 2025, with weekly summer peaks above 95%. [21][31] High utilization spreads fixed costs across more barrels, but it also leaves less slack when a refinery suffers an outage.

Geographic concentration: The Gulf Coast (PADD 3) is the system's center, holding approximately 9.877 million barrels per calendar day of capacity on January 1, 2026 — 54.4% of the national total. [32][30] This concentration reflects access to crude production, ports, pipelines, salt-cavern and tank storage, petrochemical customers, and export markets.

4. The investable universe

Refining is one of the few industrials where a general investor can get relatively "pure" exposure through several mid-to-large public companies — plus diversified exposure via the majors. Scale below is U.S. refining capacity or market value as noted; capacity figures shift with closures.

Capacity concentration by owner (EIA, Jan 1, 2026): Marathon Petroleum controlled 2.986 million barrels per calendar day, Valero 2.231 million, ExxonMobil 1.967 million, and Phillips 66 1.220 million. Their combined 8.404 million barrels per day equaled 46.3% of U.S. capacity. Chevron followed with 1.060 million and PBF Energy with 1.042 million barrels per day. [33]

Publicly traded independent / refining-led companies

Publicly traded integrated majors (refining is one segment)

Major private / foreign / other owners (not directly investable)

Bottom line: unlike many industries, there are several clean public plays here — but the very largest single asset in the country is foreign-owned, and a meaningful slice of capacity sits with private and state owners a public investor cannot buy.

5. How the money works

Refiners do not bet on the price of oil going up. They earn a margin — the gap between the cost of crude going in and the value of products coming out — multiplied by how many barrels they run. The most frequent error is treating a high crude-oil price as good for "oil companies" generally. Refiners buy crude; what matters is the product-minus-feedstock spread, not the crude price alone.

The crack spread. The industry's core profit gauge is the "crack spread," named for the cracking process that breaks heavy crude molecules into lighter fuels. The most-quoted benchmark is the 3-2-1 crack spread: the gross margin from turning 3 barrels of crude into 2 barrels of gasoline and 1 barrel of distillate, calculated as [(2 × gasoline price) + (1 × distillate price) − (3 × crude price)] ÷ 3. [7] When product prices are high relative to crude, the spread widens and refiners make money; when crude is expensive relative to products, the spread narrows and refining can lose money. [7] A crack spread is not refinery EBITDA — it omits substantial costs (secondary products, freight, energy, environmental credits, maintenance, depreciation) and may use a crude benchmark or product slate different from the plant's actual barrel. [35]

Volume and utilization. Refineries have high fixed costs, so running them full is essential. Owners chase high utilization (throughput ÷ capacity) — the industry averaged ~90.6% in 2024, ~92.0% in 2025, and topped 95% in peak summer weeks. [21][31] Scheduled maintenance ("turnarounds") and unplanned outages (fires, storms) cut throughput and directly hit earnings.

Complexity and the crude discount. Crude quality and refinery configuration are inseparable. Light, low-sulfur crude is easier to process; heavy or "sour" (high-sulfur) crude requires more conversion capacity, hydrogen, energy, and sulfur removal. A refinery's Nelson Complexity Index scores its upgrading equipment: a simple "topping" plant is ~1.0, a "deep conversion" plant 9.0 or higher. Complex refineries can run cheaper heavy, sour crude and still make premium products, capturing the discount between heavy/sour and light/sweet crude. When that light-heavy differential widens, complex U.S. Gulf Coast refiners earn more; when the differential narrows, the return on that equipment erodes. [7][36]

Costs that eat the margin. Energy (natural gas to run the plant) is a large operating cost. So is RIN compliance — the cost of blending biofuels or buying credits under the Renewable Fuel Standard (see §7). [8] Refiners also pay for crude transport, catalysts, labor, and environmental compliance. BLS reported a 2025 median annual wage of $103,160 for petroleum pump-system operators, refinery operators, and gaugers within petroleum and coal products manufacturing. [37]

Putting it together — real examples. In the fourth quarter of 2025, Marathon Petroleum's Refining & Marketing segment earned about $18.65 per barrel of margin at 95% crude utilization, with refining operating cost of $5.70 per barrel (excluding planned turnarounds and depreciation), driving segment adjusted EBITDA of ~$2.0 billion — up from ~$559 million a year earlier. [18][38] That swing — a nearly 4x jump in one segment's profit year-over-year on a margin move — is cyclicality in a nutshell.

Company results show the cycle's severity more broadly. Valero's refining operating income fell from $15.803 billion in 2022 to $11.511 billion in 2023, $3.971 billion in 2024, and $4.040 billion in 2025. [39][40] In Valero's 2025 bridge, stronger gasoline margins contributed approximately $650 million and higher throughput approximately $340 million, while weaker crude differentials cost approximately $1.1 billion and weaker other-feedstock differentials approximately $600 million. Adjusted refining operating costs rose $430 million, including $197 million of energy, $84 million of employee compensation, and $69 million of maintenance. [40] HF Sinclair reported adjusted refinery gross margin of $15.37 per barrel sold in 2025, up from $10.43 in 2024. [41] These margin-per-barrel measures are not standardized across companies and should be used within each company, not compared mechanically.

What owners do with the cash. In good years refiners throw off large free cash flow and return most of it via dividends and share buybacks. Many are also integrated downstream into higher-value, steadier businesses — petrochemicals, fuel marketing/retail, and midstream pipelines (often held in separately traded partnerships, e.g. Marathon's MPLX) — to smooth the refining cycle.

6. What drives demand

Refined-product demand is ultimately demand for transportation and industrial energy:

• Gasoline — the biggest single product; U.S. demand was 8.906 million barrels per day in 2025, down from 8.967 million b/d in 2024 and still below the pre-pandemic 2019 level of ~9.4 million b/d. [11][42] Driven by miles driven, employment, and vehicle fuel efficiency.
• Distillate (diesel & heating oil) — 3.894 million b/d in 2025 (up from 3.792 million in 2024) [42]; tied to freight, agriculture, construction, and winter heating. A barometer of industrial activity.
• Jet fuel — 1.725 million b/d in 2025 (up from 1.690 million in 2024), sharply recovered from the pandemic collapse [42]; tracks air travel.
• Exports — the U.S. is a net exporter of refined products. Exports of gasoline, diesel, and jet fuel averaged ~2.4 million b/d in 2025, with gasoline exports of 902,000 b/d and jet-fuel exports of 219,000 b/d; Mexico received 54% of exported gasoline. [12][43] Exports let U.S. refiners sell into global demand even as domestic gasoline use plateaus.
• Seasonality — summer driving season and winter heating shape both volumes and product specs. Gasoline cracks usually strengthen around the summer driving season and the switch to more costly low-vapor-pressure gasoline (Reid Vapor Pressure limits); distillate demand tends to strengthen with autumn agriculture and winter heating. Planned refinery maintenance commonly peaks in late winter and early spring. [44]

Structural forces (forward-looking): The emerging demand mix is more nuanced than "oil demand is declining." Domestic gasoline appears mature and faces efficiency and EV substitution. Diesel remains linked to freight, industry, agriculture, and heating, while jet fuel benefits from air-travel growth and has fewer near-term substitutes. Asphalt, lubricants, coke, and petrochemical feedstocks have still different end markets. The likely industry problem is not that every refinery product disappears together; it is that marginal gasoline demand weakens while refineries still produce a joint barrel whose yields cannot be radically changed. Refiners increasingly view exports and petrochemical feedstocks as the growth outlets that offset flat-to-declining domestic gasoline.

7. Regulation

Refining is heavily regulated on environmental, safety, and fuel-quality grounds. Key regimes:

• Clean Air Act fuel standards (EPA): federal rules dictate fuel composition — Tier 3 low-sulfur gasoline, seasonal Reid Vapor Pressure (RVP) limits (how easily gasoline evaporates), and reformulated gasoline in smoggy metro areas. Meeting these specs requires expensive processing units. Beyond fuel specs, refineries face Clean Air Act requirements covering hazardous pollutants, sulfur oxides, volatile organic compounds, equipment leaks, wastewater systems, flares, and new-source performance. [45]
• Renewable Fuel Standard (RFS) — RINs (EPA): the RFS requires refiners and importers ("obligated parties") to blend rising volumes of biofuels or buy compliance credits called RINs (Renewable Identification Numbers), the "currency" of the program. [8] EPA's finalized total applicable renewable-fuel requirement is 26.81 billion RINs for 2026 and 27.02 billion for 2027, including partial reallocation of earlier small-refinery exemptions. [46] RIN costs are a material and volatile expense. Refiners with strong blending and retail systems can generate or capture credits; merchant refiners with deficits must buy them. Small Refinery Exemptions (SREs) can waive obligations for smaller plants; in August 2025 EPA acted on 175 petitions, granting full or partial relief on 140 of them and removing ~1.4 billion RINs from compliance demand — a decision that moves RIN prices and refiner economics. [9]
• State programs: California's Low Carbon Fuel Standard (LCFS) and CARB fuel rules are the strictest in the nation and have made West Coast refining structurally harder — a factor in recent California closures.
• Safety & emissions: OSHA Process Safety Management, EPA Risk Management Program, and greenhouse-gas rules govern operations. Refineries also carry water, hazardous-waste, soil-remediation, and eventual decommissioning liabilities. Legacy contamination can survive a change of ownership, making environmental diligence central to private transactions. Permitting a new refinery is effectively prohibitive.
• The Jones Act: a 1920 law requiring goods shipped between U.S. ports to move on U.S.-built, U.S.-flagged vessels raises the cost of moving fuel domestically (e.g., Gulf Coast to Northeast), shaping regional supply and pricing.

8. Competitive dynamics & consolidation

• Concentrated and consolidating. Four firms hold 52% of receipts and twenty hold 95% [2]. Decades of mergers (e.g., Marathon–Andeavor in 2018) built today's giants, and the top three independents each run 2–3 million barrels per day.
• A shrinking asset base. With no new refineries being built and permitting nearly impossible, the competitive game is about running existing assets better and rationalizing weak ones. Recent U.S. closures: LyondellBasell's ~264,000 b/cd Houston refinery (March 2025), Phillips 66's ~139,000 b/cd Los Angeles refinery (October 2025), and Valero's ~145,000 b/d Benicia, CA refinery (ceasing in 2026). [13][14] These removed roughly 400,000+ b/d and cut the count to 130 plants. [4][13]
• Regional imbalance. The Gulf Coast (PADD 3) produces far more fuel than it consumes and exports the surplus; the West Coast (PADD 5) is isolated, high-cost, and shrinking under California policy, tightening regional supply. National concentration does not determine local market tightness. California-grade gasoline, limited pipeline connectivity, and long marine resupply routes make West Coast capacity more locally consequential than the national ownership percentages imply. [14]
• Integration as strategy. The strongest players diversify into midstream, chemicals, marketing, and low-carbon fuels (renewable diesel) to dampen the refining cycle.

9. Risks

• Margin cyclicality. Crack spreads swing violently; a great year and a loss year can be 18 months apart. Earnings and share prices follow.
• Energy-transition demand risk (long-term). EV adoption and efficiency gains threaten gasoline volumes over time; the pace is the key uncertainty. Substitution risk is uneven: road gasoline is most exposed to electrification and efficiency, while aviation, heavy freight, asphalt, lubricants, and petrochemical feedstocks have slower substitution paths.
• Regulatory cost and policy shifts. RIN prices, SRE decisions, California LCFS, and GHG rules can each swing profitability and, in extreme cases (West Coast), force closures. [9][14]
• Operational hazards. Fires, explosions, corrosion, catalyst failures, hurricanes, freezes, floods, utility losses, cyberattacks, or a poor restart can remove an entire facility or conversion unit from service abruptly (e.g., PBF's 2025 Martinez refinery fire). [19] Because regional product specifications and pipeline connections differ, an outage can simultaneously hurt the affected owner and raise margins for competitors.
• Feedstock and geopolitical exposure. Access to advantaged crude, sanctions (the Citgo/Venezuela saga [16]), OPEC+ supply decisions, and crude-quality differentials all move the input side of the margin. Complex refiners benefit from discounted heavy crude only while the discount exceeds their extra conversion and operating costs.
• Capital intensity and fixed costs. High break-even volumes mean downturns bite hard; a plant that can't run near capacity becomes a closure candidate.
• Labor constraints. Labor is a smaller dollar cost than crude but a critical reliability constraint. Experienced operators, instrument technicians, inspectors, engineers, and turnaround contractors are difficult to replace quickly; retirements, union disputes, or contractor scarcity can delay maintenance and restarts. [37]

10. How to invest, and the outlook

Public-market routes

• Independent refiners — Marathon Petroleum (MPC), Valero (VLO), and Phillips 66 (PSX) offer the largest, most liquid pure exposure; PBF Energy (PBF), HF Sinclair (DINO), Delek (DK), CVR Energy (CVI), and Par Pacific (PARR) add smaller, higher-beta plays. [17][19][20] None is perfectly pure: Valero owns renewable-diesel and ethanol operations; Marathon owns a large interest in MPLX; Phillips 66 has midstream, chemicals, marketing, and renewable-fuel assets; HF Sinclair has lubricants and logistics.
• Integrated majors — ExxonMobil (XOM) and Chevron (CVX) give diversified exposure where refining is one cyclical segment inside a larger oil-and-gas business; upstream or chemicals can offset — or overwhelm — refining results. [5]
• Income angle — capital returns (dividends + buybacks) are central to the refiner thesis; midstream affiliates and partnerships (e.g., MPLX) offer steadier, yield-oriented exposure to the same value chain, though those businesses are outside NAICS 324110.
• The cyclical discipline — these are classic "buy when margins and valuations are depressed, harvest when the cycle turns" stocks, not steady compounders. Investors should model refinery-by-refinery capacity, complexity, crude access, regional cracks, turnaround schedules, and environmental-credit position rather than applying one national crack spread to consolidated earnings.

Private-market routes

• Direct refinery ownership is effectively closed to individuals — assets are held by public companies, foreign national oil companies (Saudi Aramco/Motiva), and private conglomerates (Koch/Flint Hills). Entry happens at the scale of the 2025 Citgo auction (~$5.9 billion), i.e., institutional capital and distressed-asset buyers only. [15][16][24] The apparent purchase price can be misleading: working capital, inventories, environmental remediation, required maintenance, RIN deficits, union obligations, logistics contracts, and eventual decommissioning can exceed headline consideration.

Near-term drivers (forward-looking):

• Tightening supply supports margins. Continued U.S. and global refinery closures against still-large fuel demand is the bull case for surviving refiners' crack spreads.
• Exports as the release valve. With domestic gasoline flat, refined-product exports (especially diesel from the Gulf Coast) are a key growth channel. [12][43]
• Policy swings. RFS volumes, RIN prices, and Small Refinery Exemption decisions can move earnings quarter to quarter. [9][46]
• West Coast squeeze. California closures tighten PADD 5 supply and can widen West Coast margins even as they shrink the asset base. [14]
• The transition clock. The long-term question — how fast EVs erode gasoline demand — hangs over terminal-value assumptions for every refiner, even as near-term cash flows stay strong.

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Sources

1. U.S. Census Bureau, County Business Patterns (CBP), 2023 — establishments (143), employment (55,064), annual payroll ($8.92B), Q1 payroll ($2.95B) for NAICS 324110. https://www.census.gov/programs-surveys/cbp.html
2. U.S. Census Bureau, 2022 Economic Census — Concentration Ratios / Selected Statistics by Industry — receipts ($825.2B), firms (50), CR4/CR8/CR20/CR50, HHI (853.2) for NAICS 324110. https://www.census.gov/programs-surveys/economic-census.html
3. U.S. Small Business Administration, Table of Small Business Size Standards, 2023 — 1,500-employee standard for NAICS 324110. https://www.sba.gov/document/support-table-size-standards
4. U.S. Energy Information Administration, "U.S. refining capacity decreased during 2025," Today in Energy, 2026 — 130 operable refineries, 18.16 million b/cd on Jan 1, 2026. https://www.eia.gov/todayinenergy/detail.php?id=67807
5. U.S. Energy Information Administration, Refinery Capacity Report 2025 (and BOE Report summary, June 2026) — Marathon ~2.99M bpd/16.4%, Valero ~2.23M bpd/12%, largest single refineries. https://www.eia.gov/petroleum/refinerycapacity/
6. Wikipedia, "Petroleum refining in the United States," 2026. https://en.wikipedia.org/wiki/Petroleum_refining_in_the_United_States
7. U.S. Energy Information Administration, "3:2:1 Crack Spread" explainer, 2025. https://www.eia.gov/todayinenergy/includes/crackspread_explain.php
8. U.S. Energy Information Administration, "The Renewable Fuel Standard Program, RVOs, and RINs explained," Today in Energy, 2019/2025. https://www.eia.gov/todayinenergy/detail.php?id=41975
9. U.S. Environmental Protection Agency, "August 2025 Decisions on Petitions for RFS Small Refinery Exemptions," 2025. https://www.epa.gov/renewable-fuel-standard/august-2025-decisions-petitions-rfs-small-refinery-exemptions
10. [Superseded by [46] — see finalized RFS standards.]
11. U.S. Energy Information Administration, "Transportation fuel demand remains below pre-pandemic levels," Today in Energy, 2025 — gasoline ~8.9M b/d, distillate ~3.8M b/d, jet ~1.8M b/d. https://www.eia.gov/todayinenergy/detail.php?id=66005
12. BIC Magazine / U.S. Energy Information Administration, "U.S. gasoline export increased slightly in 2025," 2025 — refined-product exports ~2.4M b/d. https://www.bicmagazine.com/industry/refining-petrochem/us-gasoline-export-increased-slightly-in-2025/
13. Oil & Gas Journal / EIA, "U.S. refinery capacity declines in 2025 amid plant closures," 2026 — Valero Benicia ~145,000 b/d ceasing 2026. https://www.ogj.com/refining-processing/refining/capacities/news/55387379/
14. Houston Public Media, "LyondellBasell's Houston-area refinery to begin closure," 2025 — Houston ~264,000 b/cd; regional/PADD effects. https://www.houstonpublicmedia.org/articles/news/energy-environment/2025/01/23/511770/
15. Bloomberg, "Aramco's Motiva Expands Texas Refinery to Become Largest in US," Feb 2025 — Port Arthur ~654,000 bpd, Saudi Aramco ownership. https://www.bloomberg.com/news/articles/2025-02-11/
16. Fortune, "$10 billion Citgo auction…," Sept 2025, and reporting on the November 2025 Amber Energy (Elliott) ~$5.9B winning bid; PDVSA/Venezuela background. https://fortune.com/2025/09/19/citgo-auction-venezuela-elliott/
17. Disfold, "Top largest US Oil & Gas Refining & Marketing Companies 2026" — market caps: Phillips 66 ~$52.8B, Valero ~$51.4B, Marathon ~$50.2B, Delek ~$1.79B. https://disfold.com/united-states/industry/oil-gas-refining-marketing/companies/
18. Yahoo Finance / StockTitan, Q4 2025 refiner earnings — Marathon R&M adjusted EBITDA ~$2.0B, margin ~$18.65/bbl, 95% utilization. https://finance.yahoo.com/news/refiners-quiet-winners-2026-wall-152554757.html
19. PBF Energy, corporate refineries page and 2025 10-K (Martinez fire, RIN costs) — ~1.0M bpd across ~7 refineries. https://www.pbfenergy.com/refineries/
20. PitchBook / SeekingAlpha, HF Sinclair company profile, 2026 — ~678,000–716,000 bpd across 7 refineries. https://pitchbook.com/profiles/company/41039-56
21. BOE Report / EIA, "US refinery utilization hits highest in over two years," 2025 — 2024 annual utilization ~90.6%, weekly peaks >95% in 2025. https://boereport.com/2025/07/23/us-refinery-utilization-hits-to-highest-in-over-two-years-eia-says/
22. NS Energy / Wikipedia, "ExxonMobil Baytown Refinery" — ~584,000 bpd; Baton Rouge ~522,000 bpd. https://www.nsenergybusiness.com/projects/exxonmobil-baytown-refinery/
23. U.S. Energy Information Administration, "When was the last refinery built in the United States?" FAQ — 45,000 bpd Galveston refinery in 2022; Marathon Garyville 1977 newest with significant conversion capacity. https://www.eia.gov/tools/faqs/faq.php?id=29&t=10
24. Flint Hills Resources, "Who We Are" — Pine Bend refinery stated crude capacity of 375,000 bpd; Koch Industries ownership. https://www.fhr.com/who-we-are
25. U.S. Census Bureau, NAICS 324110 definition, 2022 — official scope of petroleum refineries. https://www.census.gov/naics/?details=324110&input=324110&year=2022
26. U.S. Energy Information Administration, "Refining crude oil — the refining process" — fractionation, conversion units, hydrotreating process description. https://www.eia.gov/energyexplained/oil-and-petroleum-products/refining-crude-oil-the-refining-process.php
27. U.S. Energy Information Administration, "U.S. refineries' ability to increase diesel production" — diesel yield flexibility limited to 29.7%–30.3% even with $0.50/gal premium. https://www.eia.gov/finance/markets/products/production.php
28. Motiva Enterprises, "About Us" — Port Arthur total throughput capability of 730,000 bpd. https://www.motiva.com/about-us
29. U.S. Energy Information Administration, "U.S. refinery capacity increased during 2024," Today in Energy, 2025 — refinery count includes alkylate-only facility. https://www.eia.gov/todayinenergy/detail.php?id=65624
30. U.S. Energy Information Administration, Refinery capacity data series — national capacity 18.160 million b/cd, stream-day 19.157 million b/d, Jan 1, 2026. https://www.eia.gov/dnav/pet/pet_pnp_cap1_dcu_nus_a.htm
31. U.S. Energy Information Administration, Annual utilization data series — 92.0% in 2025, 78.9% in 2020. https://www.eia.gov/dnav/pet/PET_PNP_UNC_A_%28NA%29_YUP_PCT_A.htm
32. U.S. Energy Information Administration, Gulf Coast (PADD 3) refinery capacity data — 9.877 million b/cd, 54.4% of national capacity. https://www.eia.gov/dnav/pet/pet_pnp_cap1_dcu_R30_a.htm
33. U.S. Energy Information Administration, Refinery Capacity Report Table 5 — capacity by company: Marathon 2.986M, Valero 2.231M, ExxonMobil 1.967M, Phillips 66 1.220M, Chevron 1.060M, PBF 1.042M b/cd. https://www.eia.gov/petroleum/refinerycapacity/table5.pdf
34. Delta Air Lines, 2025 Form 10-K — Monroe Energy/Trainer refinery ownership, jet-fuel cost hedging strategy. https://www.sec.gov/Archives/edgar/data/27904/000002790426000013/dal-20251231.htm
35. U.S. Energy Information Administration, "What is the crack spread?" Today in Energy — crack spread does not equal refinery profit, excludes secondary products and operating costs. https://www.eia.gov/todayinenergy/detail.php?id=1630
36. U.S. Energy Information Administration, "Crude oil quality affects refinery operating costs," Today in Energy — heavy/sour crude processing requires more conversion capacity. https://www.eia.gov/todayinenergy/detail.php?id=33012
37. U.S. Bureau of Labor Statistics, NAICS 324 Industry-at-a-Glance — 2025 median wage $103,160 for refinery operators/gaugers. https://www.bls.gov/iag/tgs/iag324.htm
38. Marathon Petroleum, Q4 2025 Earnings Release — refining margin $18.65/bbl, operating cost $5.70/bbl excluding turnarounds/depreciation. https://www.sec.gov/Archives/edgar/data/1510295/000151029526000003/mpcq42025earningsrelease.htm
39. Valero Energy, 2023 Form 10-K — refining operating income $11.511B (2023), $15.803B (2022). https://www.sec.gov/Archives/edgar/data/1035002/000103500224000007/vlo-20231231.htm
40. Valero Energy, 2025 Form 10-K — refining operating income $4.040B (2025), $3.971B (2024); margin bridge analysis. https://www.sec.gov/Archives/edgar/data/1035002/000162828026011499/vlo-20251231.htm
41. HF Sinclair, 2025 Form 10-K — adjusted refinery gross margin $15.37/bbl (2025), $10.43/bbl (2024). https://www.sec.gov/Archives/edgar/data/1915657/000191565726000016/dino-20251231.htm
42. U.S. Energy Information Administration, Product supplied data series — 2025 gasoline 8.906M b/d, distillate 3.894M b/d, jet 1.725M b/d. https://www.eia.gov/dnav/pet/pet_cons_psup_dc_nus_mbblpd_a.htm
43. U.S. Energy Information Administration, "U.S. transportation fuel exports grew in 2025," Today in Energy — gasoline exports 902,000 b/d, jet 219,000 b/d; Mexico 54% of gasoline exports. https://www.eia.gov/todayinenergy/detail.php?id=67304
44. U.S. Energy Information Administration, "Refinery seasonality and product prices" — summer/winter demand patterns, turnaround timing. https://www.eia.gov/finance/markets/products/prices.php
45. U.S. Environmental Protection Agency, "Clean Air Act Standards and Guidelines for Petroleum Refineries" — CAA requirements for refineries. https://www.epa.gov/stationary-sources-air-pollution/clean-air-act-standards-and-guidelines-petroleum-refineries-and
46. U.S. Environmental Protection Agency, "Final Renewable Fuel Standards for 2026 and 2027" — finalized RVOs 26.81B RINs (2026), 27.02B (2027). https://www.epa.gov/renewable-fuel-standard/final-renewable-fuel-standards-2026-and-2027

Note: the Nelson Complexity Index description (§5) reflects standard industry definitions as summarized by refining-margin references (e.g., BrentChart, RBN Energy, EIA crack-spread materials).