Filing in this field is highly concentrated: the leading assignee alone holds 1,113 of the 2,044 records in scope, and the top five assignees combined account for 68.4% of all records. This reflects the fact that major oilfield services companies have been filing continuation and multi-jurisdiction applications around core cement chemistry for decades. Smaller assignees in the ranked list typically hold only a handful of families each, often centred on regional formulations or niche additive chemistries rather than broad composition claims.

Filing peaked at 94 records in 2020 and has since eased, with the last fully comparable years showing 75 filings in 2021 falling to 44 in 2024 — a 41% decline. That does not necessarily mean R&D activity itself has slowed; publication lags filing by roughly 18 months, so 2025 and 2026 figures are still incomplete and should not be read as confirming a continued drop. The clearer signal is that the 2018-2020 filing surge has not been sustained at the same pace since.

Materials chemistry dominates: C09K (materials for miscellaneous applications) appears in 70.6% of the 2,044 records and C04B (cements, ceramics and refractories) in 65.8%, meaning most patents are chemistry-first formulation claims. E21B (earth and rock drilling) overlaps with 37.0% of records, reflecting patents that combine slurry chemistry with wellbore mechanics. Digital control (G06F) and analytical testing (G01N) are minor by comparison, each under 2% of records, indicating that software-driven or instrumentation-heavy approaches are a small slice of the field.