What Brazil patents and what the world publishes

A patent is a claim on a technique: it says someone judged an invention worth the cost of protecting it in this jurisdiction. A paper is a claim on attention: it says someone judged a problem worth working on and publishing. The two answer different questions, and an industry that reads only one of them mistakes the map for the territory.

Neither source has a field that says "this is oil and gas". In the INPI record the only sector proxy available is the IPC, the WIPO classification the office applies to the technical content of each filing, so the vertical is defined as a set of codes rather than as a keyword query. In OpenAlex the selection is a set of topics, chosen editorially and published together with what was rejected and why — methane hydrates, for instance, were left out because a sample of titles showed most of the literature is marine biogeochemistry rather than industry work, and including it would have grown the universe by more than a third.

The vertical holds 28,582 patents carrying at least one core IPC code, filed by 5,031 distinct entities and signed by 28,893 inventors. 4,428 of them are granted in the base, about 15% of the universe. Filing peaks in 2013 at 3,114 and settles near 700 a year through the early 2020s; the last two years always read low because a filing stays confidential for 18 months.

Corporate families make the concentration legible: Halliburton at 4,680 patents, Baker Hughes at 1,933, SLB at 1,460, Shell at 1,065 and Petrobras at 947. Four of those five are foreign service companies, and the count of legal entities behind each family says something on its own — Petrobras is fragmented across 108 spelling variants against Halliburton's 27, so any ranking built on raw filer strings understates the national operator more than it understates the foreign ones.

Origin points the same way. Foreign filers account for 11,016 patents with a declared country and a further 10,599 estimated from the legal form in the name, against 1,189 declared and 1,765 estimated Brazilian ones. Yet the market is not concentrated by the usual test: the Herfindahl index over normalised filers stays under 700 in every five-year window, and falls to 322 in 2020–2024. A single leader with 21.7% of the largest class coexists with a long tail of nearly a thousand filers per window.

Grant rates are where the operator and the service companies separate. Petrobras's main entity shows 332 grants on 659 filings; Halliburton's shows 298 on 4,515. Grants lag filings by years, so this is not a quality verdict — but it does mean the foreign volume in the record is largely a stock of pending claims, not of enforceable ones.

The panel profiles 355,111 works out of an estimated 771,387 in the 1990–2025 window; the collected years are 2016–2025, and the page says so rather than presenting a partial series as a complete one. That is the honest way to read it: absolute volume mixes real growth with indexing growth, while the composition of a year is immune to both.

China publishes 79,741 works to the United States' 52,916, and the five largest institutions in the corpus are all Chinese, including CNPC and Sinopec alongside the petroleum universities. Brazil holds 6,595 works, 2.67% of those with a declared affiliation.

The Brazilian slice is distinctive in shape, not in size. Its largest institution is Petrobras with 1,773 works, ahead of UFRJ at 799 and Unicamp at 766 — an operator outranking the universities. A third of Brazilian works have an international co-author against a quarter worldwide, and 22.6% pair academia with industry against 13.7% worldwide. By link of the chain, Brazil leans towards processing (9.3% against 5.1%) and away from transition topics (14.5% against 17.9%).

The two corpora disagree about who matters, and the disagreement is the finding. The patent record is dominated by foreign suppliers of well technology; the literature is anchored by a national operator that co-publishes with universities and with industry at rates above the world average. Brazil produces knowledge in this industry through a public company and its academic partners, and imports the protected techniques from service firms.

That has a practical consequence for anyone monitoring the sector: a technology becoming visible in the Brazilian literature does not imply it is being appropriated here, and a shift in filings does not imply a shift in local capability. Each panel answers for its own corpus, and a claim that crosses them needs to name which one it rests on.

The movement inside the patent record is worth watching on its own terms. Between the older and the more recent window, well-completion fluids (C09K 8) lose 2.96 points of share and production methods (E21B 43) lose 1.89, while control and monitoring of well operations (E21B 41) gains 1.57 — a drift from chemistry and mechanics towards instrumentation.