Lost Circulation Patents: Who Leads, Where the Gaps Are 2026
- 80.1% of the field sits with five filers. 1,106 of 1,381 records in scope belong to the top five assignees, with the leader alone holding 764 — a landscape where nearly every new filing lands adjacent to an incumbent's existing claims.
- Filing has cooled from its 2017 peak. Annual filings ran from 49 in 2017 down to 21 in 2021 and 14 in 2024, a -33% move over that three-year span — read cautiously since 2025 onward is still filling in behind an 18-month publication lag.
- Two IPC classes carry the whole field. C09K (materials) and E21B (drilling) cover 76.0% and 60.2% of all 1,381 records respectively; every other class, from cement chemistry to data processing, sits under 5%.
Filing growth compares 2021 (21 records) with 2024 (14) — 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 1,381 records in scope (CR5), not by the ranked leaders only.
What the lost circulation control patent record shows
Lost circulation control covers the materials and methods used to seal fractures, thief zones and weak formations while drilling — bridging particles, wellbore-strengthening fluids, squeeze treatments and the sealing-capacity models used to size them. The 1,381 records in scope run from 2015 through the current data cut-off, and the filing pattern is unusually top-heavy: five assignees account for 80.1% of everything filed, with a single leader holding more than half the total on its own.
That concentration means most of the addressable claim space around bridging-particle sizing, fracture-seal integrity testing and squeeze-plug formulation is already occupied by a small number of oilfield service majors. The open ground, where it exists, sits in the smaller IPC classes and in combinations the leaders have not yet claimed together.
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Filing trend and technology composition
Two views of the same 1,381-record dataset: how filing volume has moved year over year, and which IPC subclasses carry the technical substance of the field.
Filing trend: a 2017 peak, then a step down
Filings peaked at 49 in 2017 and have since settled lower, with the 2021-to-2024 window (a fair comparison since 2024 is the most recent complete year) running from 21 down to 14 filings, a -33% change. Years after 2024 will keep revising upward as publication catches up with filing, so the apparent recent drop should not be read as the field slowing down.
IPC composition: two dominant classes, a long thin tail
C09K (materials for miscellaneous applications) and E21B (earth and rock drilling) between them cover the great majority of records — 76.0% and 60.2% of the 1,381 in scope — because most lost circulation filings claim both a material and a drilling method. Everything else, including cement chemistry (C04B, 4.8%), testing methods (G01N, 3.9%) and polymer chemistries (C08L, C08F, C08G, each under 3%), is a minority share and a candidate for closer inspection when looking for open claim territory.
Shares are the percentage of the 1,381 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Lost Circulation Control with Eureka
This page is one run against one query. Ask Eureka your own question about lost circulation control and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited records in the field
EP3495606A2 — Wellbore strengthening and fracture-sealing method (Halliburton)
Wellbore strengthening fluids, sealing compositions, a sealing capacity characterization method for a fracture sealing composition, and a method for sealing a fracture of a weak zone of a wellbore with sealing particles in a wellbore fluid are provided. The wellbore strengthening fluids may contain a plurality of sealing particles selected on the basis of unit slot length spurt loss volume, with 5 to 35 percent of the particles by volume sized at 100 to 150 percent of a selected fracture sealing width.Abstract excerpted from the published filing.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20040244978A1 | Lost circulation material blend offering high fluid loss with minimum solids | 256 |
| 2 | US7284611B2 | Methods and compositions for controlling lost circulation in subterranean operations | 180 |
| 3 | US20100224365A1 | Method of treating a subterranean formation and forming treatment fluids using chemo-mathematical models and … | 166 |
| 4 | US3606924A | Well tool for use in a tubular string | 128 |
| 5 | US20090029878A1 | Drilling fluid, drill-in fluid, completition fluid, and workover fluid additive compositions containing therm… | 126 |
| 6 | US6017854A | Simplified mud systems | 120 |
| 7 | US20100230169A1 | Compositions and methods for inhibiting lost circulation during well operations | 105 |
| 8 | US4391925A | Shear thickening well control fluid | 97 |
| 9 | US20100230164A1 | Compositions and methods for inhibiting lost circulation during well operation | 92 |
| 10 | US20060096759A1 | Methods and compositions for controlling lost circulation in subterranean operations | 91 |
Citation counts favour older filings simply because they have had longer to accumulate references inside the searched corpus — treat them as a marker of influence on later filings, not of current commercial importance.
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 read-throughs of the concentration, trend and geography data that matter before drafting new claims in this space.
The leadership block is unusually tight
Five assignees hold 1,106 of the 1,381 records in scope, and the leader alone accounts for 764. A tenth-place filer holds only 19 records, so the drop-off from the leadership block to the rest of the field is steep rather than gradual.
Volume has stepped down from a 2017 peak
Filings ran at 49 in 2017 and have since eased to 14 by 2024. The most recent one or two years will revise upward as publication lag closes, so this is a real medium-term cooling, not a cliff.
Materials and drilling method claims dominate together
Most filings pair a C09K materials claim with an E21B drilling-method claim, which is why both classes show high shares against the same 1,381-record base. Smaller classes like C04B and G01N point to where sealing-integrity testing and cement-chemistry claims remain comparatively thin.
Filing offices track the operator base
The United States leads receiving offices with 421 records, followed by WIPO/PCT filings at 195 and Canada at 159 — a spread that mirrors where large-scale drilling programmes and their operators are concentrated.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to lost circulation control, with the prior art for and against each one.
The assignee landscape
A ranking of 100 companies, drawn from the full 1,381-record dataset, shows a small leadership group holding most of the field and a long tail of single- or few-filing entrants behind them.
One filer holds more than half the field
The leading assignee's 764 records against a 1,381-record total means over half of everything published in this space traces back to a single company's filing programme, spanning materials, sealing methods and characterization techniques.
The gap from top to fifth is already steep
Fifth place holds 26 records against the leader's 764 — the leadership block is front-loaded, and by tenth place the count is down to 19, meaning most of the ranked 100 companies hold only a handful of families each.
Momentum has gone quiet across the top of the table
Every one of the leading assignees shows zero filings in the latest year on record, consistent with the broader publication lag rather than a genuine stop in R&D — activity from the last 12-18 months has not yet cleared the pipeline.
Joint filings cluster inside corporate families
The strongest co-assignee pairs in the dataset link related entities within the same corporate group rather than independent partners, which limits how much cross-company collaboration signal can be read from the co-filing data.
| Assignee | Recent year | YoY |
|---|---|---|
| Halliburton Energy Services, Inc. | 0 | -100% |
| M-I L.L.C. | 0 | — |
| Saudi Arabian Oil Co. (Saudi Aramco) | 0 | — |
| BP Corporation North America Inc. | 0 | — |
| Weatherford Technology Holdings, LLC | 0 | — |
| Baker Hughes Company | 0 | — |
| ExxonMobil Technology & Engineering Company | 0 | — |
| Exxon Production Research Company | 0 | — |
Where to take this next
The dataset points to a field where the top claims are locked in but the smaller technical branches remain comparatively open.
Run a freedom-to-operate check on the smaller IPC classes
C04B, G01N and the polymer chemistry classes carry a fraction of the filing density of C09K and E21B, which is where a narrower claim is more likely to clear prior art.
Explore white space in EurekaTrack the leadership block's dormant filings
Zero latest-year filings across the top assignees likely reflects publication lag rather than a real pause — worth revisiting this trend line in 12 months.
Set up monitoring in EurekaMap the most-cited prior art before drafting
The five most-cited records anchor the field's foundational claims on bridging particles and wellbore strengthening; any new filing should be checked against them directly.
Review citations in EurekaCommon questions about lost circulation control patents
The assignee ranking for this dataset covers 100 companies, and it is heavily front-loaded: the leading filer holds 764 of the 1,381 records in scope, and the top five together hold 1,106 records, or 80.1% of the field. By the tenth-ranked company the count has fallen to 19 records, so beyond the leadership block the field is a long tail of companies with only a handful of filings each. This concentration means most of the well-known bridging-particle and wellbore-strengthening claim space is already occupied by a small number of oilfield service majors.
Filings peaked at 49 in 2017 and have eased since, with the 2021-to-2024 window running from 21 down to 14, a -33% change over that span. However, patent publication typically lags filing by around 18 months, so the last one to two years of any filing trend are always undercounted at the time of measurement. Treat the recent-year numbers as provisional and the 2021-2024 comparison as the more reliable read on direction.
Two IPC classes cover the great majority of filings: C09K, materials for miscellaneous applications, appears in 76.0% of the 1,381 records, and E21B, earth and rock drilling, appears in 60.2%. Because most filings claim both a sealing material and a drilling or treatment method, these two shares overlap heavily rather than being separate camps. Smaller classes such as cement chemistry (C04B), testing methods (G01N) and various polymer chemistries each cover under 5% of records and represent comparatively thinner claim territory.
EP3495606A2 is a Halliburton filing describing wellbore strengthening fluids and sealing compositions, together with a sealing capacity characterization method and a method for sealing fractures in weak wellbore zones. Its claims are built around particle sizing logic, specifically sealing particles selected so that 5 to 35 percent of them by volume have at least one dimension sized to 100 to 150 percent of a target fracture sealing width. Anyone drafting a bridging-particle or wellbore-strengthening claim in this space should check their sizing methodology against this filing directly, since it sits inside one of the most heavily-cited clusters in the dataset.
The clearest opportunities sit in the IPC classes with low record shares against the 1,381-record total, including cement squeeze plug formulation chemistry (C04B, 4.8%), fracture-seal integrity testing methods (G01N, 3.9%), and the smaller polymer chemistry classes (C08L, C08F, C08G, each under 3%). These are not necessarily easier to file because they are novel; they are less crowded because the incumbent leaders have concentrated their claims in materials and drilling-method combinations instead. A freedom-to-operate search focused on these smaller classes is a reasonable starting point before drafting.
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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.