Drilling Fluid Rheology Patents: Who Leads, Where the Gaps Are 2026
- 63.7% concentration. The top 5 assignees hold 1,206 of the 1,892 records in scope — filing here is dominated by a small group of oilfield services majors, not a fragmented field.
- Filings down 69% since the last complete peak. Publications fell from 64 in 2021 to 20 in 2024; 2025-2026 figures are still filling in due to publication lag and should not be read as a continued decline yet.
- Two IPC classes carry the field. E21B (53.9%) and C09K (51.7%) between them cover most records, while control-systems and data-processing classes stay under 2% — a sign hydraulics modelling is still thinly claimed.
Filing growth compares 2021 (64 records) with 2024 (20) — 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 1,892 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
Drilling fluid rheology and hydraulics patents span the physics of how mud behaves in the wellbore annulus and the engineering used to control it: Herschel-Bulkley and other yield-stress models, equivalent circulating density (ECD) calculations, gel strength and barite sag management, and surge/swab pressure prediction during pipe movement. The search set combines rheology-model terms with hydraulics terms so that records must address both the fluid behaviour and its pressure consequence in the well.
Coverage runs from 2015 through the 2026 cut-off, drawing on 1,892 published records. Because publication trails filing by roughly 18 months, the most recent one to two years understate real filing activity and are best read as provisional.
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Filing trends and technology composition
Two views of the same 1,892-record set: how filing activity has moved year over year, and which IPC subclasses carry the technical weight.
A field that peaked in 2020 and has since cooled
Annual publications rose to a peak of 83 in 2020, then declined; the last complete comparison shows 2021 at 64 falling to 2024 at 20, a 69% drop over that three-year span. 2025 and 2026 counts will rise as the publication backlog clears, so treat the tail of the chart as incomplete rather than as evidence of a further slide.
Two classes anchor the field, the rest are thin
E21B (earth and rock drilling, 53.9% of records) and C09K (materials for miscellaneous applications, covering fluid formulations, 51.7%) dominate. Everything else drops sharply: material testing (G01N, 4.0%), geophysics (G01V, 2.2%), cement and ceramics (C04B, 1.7%), control systems (G05B, 1.5%), polymer additives (C08K, 1.4%) and digital data processing (G06F, 1.4%) each cover a small slice, pointing to modelling, control-loop and real-time-computation angles that are far less crowded than the core fluid-formulation and wellbore-mechanics claims.
Shares are the percentage of the 1,892 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Drilling Fluid Rheology and Hydraulics with Eureka
This page is one run against one query. Ask Eureka your own question about drilling fluid rheology and hydraulics and every answer comes back with the patent numbers behind it.
Try EurekaMost-cited records and a representative filing
Real-time equivalent circulating density of drilling fluid (US20200362695A1, Saudi Arabian Oil Company)
The filing calculates a cuttings concentration in the annulus, derives an effective mud weight from it, and uses that effective mud weight to compute equivalent circulating density in real time, then feeds the ECD value back into control of a drilling-system component.Abstract condensed from the original filing for length.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US20140116776A1 | Methods and systems for improved drilling operations using real-time and historical drilling data | 304 |
| 2 | US20040149431A1 | Method and apparatus for a monodiameter wellbore, monodiameter casing and monobore | 251 |
| 3 | US7066284B2 | Method and apparatus for a monodiameter wellbore, monodiameter casing, monobore, and/or monowell | 233 |
| 4 | US5826669A | Drilling fluid loss prevention and lubrication additive | 188 |
| 5 | US6374925B1 | Well drilling method and system | 181 |
| 6 | US20090294174A1 | Downhole sensor system | 146 |
| 7 | US9557438B2 | System and method for well data analysis | 137 |
| 8 | US4275788A | Method of plugging a well | 136 |
| 9 | US20060157282A1 | Managed pressure drilling | 130 |
| 10 | US6281172B1 | Quaternary nitrogen containing amphoteric water soluble polymers and their use in drilling fluids | 126 |
Citation counts accumulate over time and favour older filings; use them as a signal of influence within this corpus, not of current technical 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-outs from the concentration, trend and jurisdiction data that matter more for strategy than the raw counts alone.
Core hydraulics claims are locked up by a handful of majors
With 1,206 of 1,892 records held by five assignees, freedom-to-operate work in core ECD and gel-strength claim territory should assume dense prior art from the same small set of oilfield services companies, not a fragmented landscape.
Publication volume has receded from its 2020 peak
Filing activity peaked at 83 in 2020 and has fallen through the last fully comparable years. That decline predates any effect of publication lag and reflects a genuine slowdown in new filings reaching this corpus, not a data artefact.
Filing strategy still centres on the US, with PCT and Canada close behind
The United States receives more filings than any other office (587), with PCT (218), Canada (215), EPO (201), the UK (165) and Australia (157) forming a secondary tier. A filer targeting only the US misses a meaningful share of the activity captured through the PCT route.
Real-time computation claims remain a minority track
Despite the prominence of real-time ECD and hydraulics-modelling filings among the most-cited records, digital-data-processing (G06F) and control-systems (G05B) IPC tags each cover under 2% of records, suggesting the computational layer around rheology models is still lightly claimed relative to the formulations and mechanical apparatus it supports.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to drilling fluid rheology and hydraulics, with the prior art for and against each one.
Who is filing, and where the field is thinning
The ranked leaders in this set are dominated by oilfield services and national oil companies; recent-year momentum figures show several of them at zero in the latest tracked year, consistent with the broader publication-lag effect rather than an exit from the field.
One assignee holds close to 40% of the leader tier's combined volume
The leading assignee's 719 records sit well above fifth place (63) and tenth place (29), a steep drop-off that marks this as a field led by one dominant filer rather than a tight cluster of peers.
Collaboration is limited and concentrated around national oil company partnerships
Only ten co-assignee pairings appear in the data, and the strongest of them link a national oil company to a university and to affiliated service partners. Most filing in this field happens under a single assignee name rather than through joint filings.
Latest-year counts near zero reflect publication lag, not withdrawal
Several of the largest historical filers, including the leading assignee, show zero records in the latest tracked year with year-over-year drops as steep as -100%. Given the 18-month publication lag, this is expected for any year close to the data cut-off and should not be read as those companies stepping back.
| Assignee | Recent year | YoY |
|---|---|---|
| Halliburton Energy Services, Inc. | 0 | -100% |
| M-I L.L.C. | 0 | — |
| Saudi Arabian Oil Company (Saudi Aramco) | 0 | -100% |
| Elementis Specialties, Inc. | 0 | — |
| Weatherford Technology Holdings, LLC | 0 | — |
| Weatherford Lamb, Inc. | 0 | — |
| M-I Drilling Fluids UK Ltd. | 0 | — |
| Sofitech N.V. | 0 | — |
Where to take this analysis
The dataset points to a concentrated core and a thinner computational layer around it. Two directions follow from that.
Map freedom-to-operate against the leader tier
Before drafting new ECD or gel-strength claims, run a focused search against the top-ranked assignees' active families rather than the field as a whole — that is where the density actually sits.
Explore assignee portfolios in EurekaTest the white space with a narrow first claim
The control-systems and data-processing classes are thin relative to formulation claims. A first claim tied to a specific real-time computation step, rather than the underlying fluid property, may clear more easily.
Draft and stress-test claims in EurekaCommon questions about this landscape
Filing in this field is concentrated: the leading assignee alone accounts for 719 of the 1,892 records in scope, and the top five assignees combined hold 1,206 records, or 63.7% of the total. The next tier drops off sharply, with the tenth-ranked assignee holding only 29 records. This pattern is typical of a field anchored by a small number of large oilfield services and national oil companies rather than spread across many independent filers.
Filings peaked in 2020 at 83 published records and have declined since; comparing the last two fully comparable years, 2021 (64) to 2024 (20) shows a 69% drop. Figures for 2025 and 2026 are still incomplete because publication typically lags filing by around 18 months, so the most recent one to two years will rise as more records publish and should not yet be read as a continuing decline.
Equivalent circulating density (ECD) is the effective density of drilling fluid in the wellbore annulus while circulating, accounting for friction and cuttings load, and it is one of the two search terms anchoring this dataset alongside annular pressure loss. It matters for IP because ECD calculation methods, especially real-time versions that feed back into drilling control, form one of the more heavily cited claim areas in this corpus, including the most-cited record in the set.
Two IPC subclasses dominate: E21B (earth and rock drilling, covering wells) appears in 53.9% of the 1,892 records, and C09K (materials for miscellaneous applications, covering fluid formulations) appears in 51.7%. Because a single record can carry multiple IPC classes, these two figures overlap substantially. Supporting classes such as material testing, geophysics, control systems and data processing each cover under 5% of records, indicating claim density is heavily weighted toward core drilling mechanics and fluid chemistry rather than modelling or control software.
The IPC composition data shows control systems (G05B, 1.5% of records) and digital data processing (G06F, 1.4%) are thin relative to the dominant formulation and mechanical-apparatus classes, even though real-time ECD calculation appears among the most-cited filings in the set. That gap suggests narrower opportunities around real-time control loops, barite sag prediction models, and parameter-estimation software for yield-stress models like Herschel-Bulkley, where fewer competing claims currently sit on record.
Collaboration is limited in this dataset: only ten co-assignee pairings were identified across 1,892 records. The strongest pairings link a national oil company to a university partner and to affiliated service companies, with the top pairing sharing 26 records. The overwhelming majority of filings in this field are made under a single assignee name, consistent with a field led by vertically integrated oilfield services and national oil companies rather than joint ventures or academic-industry consortia.
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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.