The assignee ranking for this dataset covers 52 companies, and it is heavily concentrated: the top 5 hold 520 of 662 records in scope, or 78.5%. The leading single assignee alone holds 235 records, far ahead of fifth place at 29. This means most of the mechanical pump architecture — fluid ends, plunger packing, manifolds — is already claimed by a small group, and any new filer should expect to encounter their prior art directly rather than file into open space.

Filings peaked at 144 in 2021 and fell to 54 by 2024, a 63% decline over that three-year span, with several leading assignees showing year-over-year drops of -82% to -100% in the most recent complete year. This likely reflects the initial wave of electric-fracturing-fleet patenting working through prosecution rather than the field disappearing. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so the most recent years should not yet be read as a continuing decline.

E21B (earth and rock drilling, wells) appears in 77.8% of the 662 records and F04B (positive-displacement pumps) in 55.4%, making mechanical pump architecture the dominant claim territory. Turbine and electric-drive-related classes are present but much thinner: F02C at 11.0%, F01D at 9.5%, and H02P (motor and generator control) at 4.5%. Because a single record can carry multiple IPC classes, these shares overlap and add to more than 100%.

Relative to the mechanical pump core, yes — classes tied to electric-drive integration and motor control (H02P at 4.5% of records) and turbine-to-pump power transmission (F02C and F01D, each under 12%) are far less densely claimed than E21B and F04B. That does not mean these areas are unclaimed outright, but claim density is lighter, and a first-filer strategy focused on supervisory control, cavitation/pulsation sensing, or modular hydration units is more likely to find room to draft around existing art.

US20210404308A1, assigned to BJ Energy Solutions, describes a supervisory controller that reads pump discharge pressure, suction pressure, speed and vibration signals along with blender flow rate and discharge pressure to detect and respond to cavitation and pulsation events during fracturing. Its scope centres on the sensing-and-intervention logic rather than the pump hardware itself, so it is most likely to constrain competing control-system and monitoring claims rather than fluid-end or manifold designs. Anyone drafting a supervisory control claim in this space should review its specific signal combinations closely before finalising claim language.