Oilwell Cement Slurry Patents: Top Companies & Filing Trends 2026
- 68.4% of all 2,044 records sit with just five assignees, and 77.3% with ten — this is a field with a dominant core, not a fragmented one.
- Filings peaked in 2020 at 94 and the 2021-to-2024 span (a complete window) shows a 41% pull-back, from 75 to 44 filings a year.
- C09K and C04B classes cover most of the corpus at 70.6% and 65.8% of records respectively, while E21B well-drilling overlap sits at 37.0% — leaving smaller classes like G06F digital slurry control at just 0.8%.
Filing growth compares 2021 (75 records) with 2024 (44) — a three-year span. 2024 is the most recent year we treat as complete: publication lags filing by roughly 18 months, so 2025 onwards are still filling in and any growth rate that ends there would understate the field. Top-5 share is the combined record count of the five largest assignees divided by all 2,044 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Oilwell cement slurry design sits at the intersection of oilfield services chemistry and wellbore engineering: formulating cement retarders and extenders to control thickening time, limit free fluid, manage slurry rheology, and stop gas migration during the critical hours after a slurry is pumped downhole. The search scope combines cement-chemistry terms with performance criteria — thickening time, compressive strength development, fluid loss — so the corpus captures both formulation patents and the testing and control methods built around them.
The dataset spans 2,044 published records filed between 2015 and mid-2026, with publication naturally lagging filing by roughly 18 months, so the last one to two years understate true filing activity. Coverage draws on receiving offices led by the United States, alongside Canada, Australia, WIPO/PCT filings, China and the United Kingdom, reflecting where oilwell cementing activity and its associated IP protection are concentrated.
Filing trends and technology composition
Two views of the same 2,044-record corpus: how filing volume has moved year over year, and how records distribute across IPC subclasses.
Filing trend: rise, peak, and pull-back
Annual filings climbed from 60 in 2017 to a peak of 94 in 2020, then eased across the following complete years, with 2021's 75 filings falling to 44 by 2024 — a 41% decline over that three-year span. 2025 and 2026 figures are still filling in behind the publication lag and should not be read as a continued fall.
Where the claims sit
C09K (materials for miscellaneous applications) touches 70.6% of records and C04B (cements and ceramics) 65.8%, confirming that most activity is chemistry-first. E21B (earth and rock drilling) appears in 37.0% of records, marking the overlap with wellbore mechanics, while G01N testing, B28C mixing equipment, C07F organo-metallic compounds and G06F digital control each cover under 4% of records — these are the classes with the least claim density.
Shares are the percentage of the 2,044 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Oilwell Cement Slurry Design with Eureka
This page is one run against one query. Ask Eureka your own question about oilwell cement slurry design and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited prior art and a representative recent filing
US11555139B2 — Real time tailoring of cement slurry for downhole thickening time
A method of cementing may include: measuring a feeding rate of water and a feeding rate of cement blend into a cement blender; calculating a cement retarder feeding rate and/or an accelerator feeding rate using a thickening time model, wherein the thickening time model uses at least a thickening time requirement, the feeding rate of water, and the feeding rate of cement blend, to calculate the cement retarder feeding rate and/or the accelerator feeding rate; introducing a cement retarder at the cement retarder feeding rate and/or an accelerator at the accelerator feeding rate into the cement blender; mixing at least the water, cement blend, and at least one of the cement retarder and/or the…Filed by Halliburton Energy Services, Inc., published 2023-01-17 — illustrates the shift from static formulation claims toward real-time, feedback-controlled slurry dosing.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4234344A | Lightweight cement and method of cementing therewith | 282 |
| 2 | US4557763A | Dispersant and fluid loss additives for oil field cements | 249 |
| 3 | US6832652B1 | Ultra low density cementitious slurries for use in cementing of oil and gas wells | 228 |
| 4 | US6145591A | Method and compositions for use in cementing | 213 |
| 5 | US6626243B1 | Methods and compositions for use in cementing in cold environments | 209 |
| 6 | US6729405B2 | High temperature flexible cementing compositions and methods for using same | 204 |
| 7 | US3499491A | Method and composition for cementing oil well casing | 201 |
| 8 | US20100044043A1 | Methods of Cementing in Subterranean Formations Using Cement Kiln Dust in Compositions Having Reduced Portlan… | 192 |
| 9 | US4340427A | Well cementing process and gasified cements useful therein | 191 |
| 10 | US7559369B2 | Well treatment composition and methods utilizing nano-particles | 183 |
Citation counts favour older filings simply because they have had more time to accumulate citations within the searched corpus — treat this table as a map of influential prior art, not of current filing activity.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Browse MCP servers →What the numbers mean for a filing decision
Three observations that go beyond the raw counts and speak to where new claims can and cannot land.
The core chemistry space is largely occupied
With 68.4% of all records held by five assignees and 77.3% by ten, foundational retarder, extender and fluid-loss-additive claims in this corpus are heavily pre-empted. New entrants filing broad composition claims in this space are filing into dense prior art.
Filing pace has cooled from its 2020 peak
Activity rose to a peak of 94 filings in 2020, then declined across the next complete filing years to 44 in 2024, a 41% drop. That reflects either claim-space saturation in core chemistry or a shift in R&D investment toward adjacent method and control claims rather than new base formulations.
Digital and testing classes are thin
Compared with C09K and C04B chemistry classes above 65%, digital data-processing overlap (G06F) sits at just 0.8% of records and analytical testing methods (G01N) at 1.9%. Real-time control approaches like the representative featured filing are a small minority of the corpus rather than the mainstream approach.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to oilwell cement slurry design, with the prior art for and against each one.
Who is filing, and where the gaps sit
A small group of oilfield services majors accounts for most activity, but the ranked list also surfaces smaller regional players filing narrower, more specific claims.
One assignee dominates by volume
The leading assignee's filing count alone exceeds half of the entire 2,044-record corpus, a scale gap that separates it from the rest of the ranked field even at fifth place (51 records) and tenth (27 records).
A steep drop-off after the top ten
Filing counts fall sharply outside the leading names — tenth place sits at 27 records against a leader with 1,113 — indicating that most of the ranked 100 companies hold only a handful of families each, often around specific regional or niche formulations.
Momentum has slowed even at the top
Recent-year filing counts for the largest assignees are low in absolute terms, with leading names logging single-digit filings in the latest tracked year and one major assignee showing a -100% year-on-year change, consistent with the broader post-2020 pull-back in the trend data.
| Assignee | Recent year | YoY |
|---|---|---|
| Halliburton Energy Services, Inc. (USA) | 2 | 0% |
| Schlumberger Technology LLC | 1 | — |
| Schlumberger Technology Corporation | 1 | — |
| Saudi Arabian Oil Co (Saudi Aramco) | 0 | -100% |
| Halliburton Company | 0 | — |
| Baker Hughes Holdings LLC | 0 | — |
| Hercules Incorporated | 0 | — |
| China National Petroleum Corporation | 0 | -100% |
Taking this further
The figures above establish where filing is concentrated and where it thins out. The next step is usually a closer read of specific claim sets.
Map claim scope against your formulation
Run your specific retarder, extender or fluid-loss chemistry against the most-cited records to see whether your composition or method falls inside existing claim boundaries before committing to a filing strategy.
Explore in Patsnap EurekaTrack momentum by assignee over time
Watch year-on-year filing changes among the leading assignees to spot whether the post-2020 pull-back continues or reverses as 2025-2026 data completes.
Set up monitoring in Patsnap EurekaInvestigate the under-claimed branches
Real-time dosing control and digital slurry feedback loops show thin filing density today — a closer prior-art read may reveal whether that reflects true white space or simply narrower claim drafting.
Search white space in Patsnap EurekaCommon questions on oilwell cement slurry patents
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.
The thinnest IPC classes in this corpus — G06F digital data processing at 0.8% of records, C07F organo-metallic compounds at 1.1%, and B28C mixing equipment at 1.4% — point to under-claimed branches relative to the dominant chemistry classes. Real-time, feedback-controlled dosing systems, of the kind illustrated in the representative recent Halliburton filing, remain a minority approach against the broader base of static formulation claims. That said, thin filing density in a class can reflect narrow drafting rather than genuine open space, so any white-space read needs a claim-level check before relying on it.
US11555139B2, assigned to Halliburton Energy Services, Inc. and published in January 2023, claims a method for calculating cement retarder or accelerator feeding rates in real time using a thickening time model driven by water and cement blend feed rates. It sits in the smaller, growing corner of the field built around real-time control rather than fixed-ratio formulation. Anyone building automated slurry dosing or feedback-based thickening time control should review this claim family closely, since it stakes out a method-level position rather than a composition, which can be harder to design around by simply reformulating the slurry itself.
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Disclaimer. This page is generated from Patsnap Eureka data drawn from a limited snapshot of global patent and scientific-literature records, and is provided for general information and reference only.
Patent data carries inherent limitations: recent filings (typically the most recent 18–24 months) are under-counted due to standard publication lag; counts may be reported at either a patent-family or a patent-record basis and are not always directly comparable; classification, applicant-name, and citation data may contain errors, duplicates, or omissions; and the underlying search query defines and constrains the scope shown. As a result, the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing on this page constitutes an exhaustive prior-art, novelty, freedom-to-operate, or validity search, nor does it constitute legal, financial, investment, or professional advice, and it should not be relied upon as such. Any patent, commercial, or strategic decision should be verified independently and reviewed with qualified patent, legal, and domain professionals. Patsnap makes no warranties, express or implied, as to the accuracy, completeness, or fitness for any particular purpose of the information presented.
Machine translation. Assignee and organisation names originally recorded in Chinese, Japanese or Korean have been rendered into English by an AI translation step so that the tables stay readable. These renderings are best-effort and may not match a company’s registered English name; the original name is what the underlying patent record carries, and it is what any Eureka query launched from this page uses.