In this landscape it covers any claimed method or system for keeping injected CO2 below the fracture pressure of a storage formation while sustaining injectivity, including injection timing, brine or water co-production, monitoring instrumentation and well completion design. Because the search terms also catch general reservoir and pressure language, the 192-record corpus includes adjacent filings from oilfield operations, water treatment and thermal cycles that use the same pressure-control mechanics outside a storage context. Readers doing freedom-to-operate work should expect to filter by the specific mechanism they care about rather than treat the whole set as CO2-specific.

The ranking is led by a single assignee with 22 records, with the top 5 assignees combined holding 23.4% of all 192 records in scope and the top 10 holding 35.9%. Beyond the leader, holdings drop off quickly, with the fifth-ranked assignee at 5 records and the tenth at 4 — a pattern of one clear leader followed by a long tail of smaller filers rather than a concentrated oligopoly. Anyone assessing competitive risk should look at the leader's claim scope specifically, since the rest of the field is fragmented.

Filings rose from 4 records in 2017 to a peak of 27 in 2021, then declined to 14 by 2024, a 48% drop over that three-year span. Because publication lags filing by roughly 18 months, 2025 and 2026 figures are still incomplete and should not be read as continued decline. The honest reading is a first wave of broad filings around 2020-2021 followed by a smaller, more targeted second wave rather than a field losing interest.

Earth and rock drilling claims (IPC class E21B), covering wellbore and injection equipment, are the largest single category at 17.2% of the 192 records. Biocide and agrochemical-classed filings (A01N) and body-fluid device claims (A61M) also appear at meaningful shares, reflecting the breadth of the underlying search terms rather than CO2-specific activity. Water treatment, thermal power, data processing, fuels and refrigeration each sit in a similar band between roughly 6% and 7%, suggesting no single adjacent technology has pulled decisively ahead once wellbore hardware is set aside.

The technology composition shows wellbore and injection hardware (E21B) as the most heavily claimed area, so novel mechanism-level claims there face the densest prior art. Areas represented at lower, roughly even shares — data processing, refrigeration cycles, thermal power integration — carry fewer records each and are worth a closer look for underclaimed combinations, particularly where a claim ties a monitoring or control method specifically to storage-site pressure limits rather than to general oilfield use.