Well Completion Patents: Who Leads, Where the Gaps Are 2026
- Filing has cooled since its 2021 peak. 129 families in 2021 fell to 98 by 2022, and the trend line has kept sliding since — a maturing claim landscape rather than a growing one.
- China now outfiles the United States at the office level. 816 Chinese receiving-office filings against 635 US filings suggests where future contests over these claims are more likely to be litigated or licensed.
- Momentum has stalled even among the largest holders. Recent-year filings from the sector's most active assignees show flat-to-negative year-on-year movement, including multiple holders at zero or -100% YoY.
Filing growth compares 2021 (129 records) with 2024 (94) — 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 2,682 records in scope (CR5), not by the ranked leaders only.
What the well completion and intervention patent set covers
This landscape tracks patent families filed under E21B43, E21B33 and E21B23 that combine well completion or intervention terminology with hardware and technique keywords: packers, sand control screens, intelligent completion, zonal isolation and coiled tubing. The core subject matter — 2,648 of 2,682 records — sits inside E21B, the earth and rock drilling subclass, confirming this is a tightly bounded mechanical and downhole-tools field rather than a loosely adjacent search.
Secondary IPC activity is thin by comparison: materials for wellbore fluids (C09K), separation processes, marine vessel integration, digital processing and cyclone or spray equipment each register in the low double digits or teens. That pattern signals a field where the dominant claim territory — the physical completion hardware itself — is well staked out, while software, materials chemistry and offshore-vessel integration remain comparatively open.
Let an AI agent run this analysis on your own technology
Pick a task. Every answer cites the patents behind it.
Filing trend and technology composition
Publication data through the 2026-07-31 cut-off shows a field that expanded through the late 2010s, peaked in 2021, and has been giving back growth since. Because publication lags filing by roughly 18 months, the last one to two years in the chart will read lower than the eventual filed total once records catch up.
A single peak, then decline
Filings rose from 88 in 2017 toward a peak of 129 in 2021, held near that level at 98 in 2022, then trended down toward 9 by 2026 — partly a publication-lag artefact, but the multi-year slide from the 2021 high is a real signal of a field that has stopped expanding its claim footprint at pace.
E21B dominates; everything else is a footnote
E21B accounts for 2,648 of 2,682 records. The next largest classes — C09K materials (132), B01D separation (35) and B63B marine vessels (26) — are an order of magnitude smaller, meaning cross-disciplinary claims combining completion hardware with materials science or offshore integration are still comparatively rare.
Shares are the percentage of the 2,682 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Well Completion and Intervention with Eureka
This page is one run against one query. Ask Eureka your own question about well completion and intervention and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art in this space
USRE36723E1 — Spoolable coiled tubing completion system
A coiled tubing completion system built with completion apparatus flush to the coiled tubing outside diameter, avoiding upsets while remaining flexible and spoolable on a standard reel. The through-bore design is large enough to pass wireline tools for other operations, and the system is built from standard coiled tubing well control equipment usable in live wells, including a tubing retrievable safety valve, an annular control valve, concentric gas lift valves, a zone packer, a landing nipple and a sliding sleeve.Filed by Camco International Inc.; reissued 2000-06-06.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4714117A | Drainhole well completion | 282 |
| 2 | US5971072A | Inductive coupler activated completion system | 275 |
| 3 | US5375661A | Well completion method | 246 |
| 4 | US6605570B2 | Compositions and methods to control fluid loss in surfactant-based wellbore service fluids | 224 |
| 5 | US6003606A | Puller-thruster downhole tool | 208 |
| 6 | US5474131A | Method for completing multi-lateral wells and maintaining selective re-entry into laterals | 205 |
| 7 | US6868906B1 | Closed-loop conveyance systems for well servicing | 201 |
| 8 | US5945387A | Polymeric well completion and remedial compositions and methods | 198 |
| 9 | US5477923A | Wellbore completion using measurement-while-drilling techniques | 198 |
| 10 | US6419014B1 | Apparatus and method for orienting a downhole tool | 192 |
Citation counts inside a searched corpus favour older filings simply because they have had longer to accumulate citations — read this as a map of foundational art, not of current competitive strength.
Each row carries its publication number; clicking a row searches Eureka by that number.
Put your own technology through the same analysis
Eureka on the web
When you want the answer in the next five minutes.
The agent works the prompt against patents and technical literature, citing every source.
Run your analysis now →MCP server & REST API
When it has to run inside your own pipeline.
Patent search, landscape analysis and assignee resolution as MCP tools. Drop them into any agent framework, or call REST directly.
Browse MCP servers →What the filing pattern means for strategy
Three structural features of this dataset matter more than any single company ranking: where filings are concentrated, where they have gone quiet, and where the technology classes barely overlap.
Hardware claims are almost the entire field
Nearly the whole corpus sits inside a single IPC subclass covering earth and rock drilling wells. Adjacent classes — materials, separation, marine, software — each contribute a small fraction, which means most competitive collision happens over mechanical completion hardware design, not chemistry or control software.
Filing centre of gravity has shifted toward China
China's receiving office now leads the United States in raw filing count, with Canada, WIPO/PCT, EPO and the UK trailing well behind. Freedom-to-operate work that stops at the USPTO and EPO will miss where the largest recent volume of new claims has actually landed.
Even the largest holders have gone quiet
Recent-year filing counts at several of the most active historical assignees, including large state and oilfield-services players, show zero filings in the latest year or year-on-year declines as steep as -100%. That is consistent with the sector-wide slide from the 2021 peak rather than any single company's retreat.
Co-filing is limited and mostly intra-group
Only ten co-assignee pairs appear in the dataset, and the strongest ones link a parent company to its own subsidiary or research institute rather than to an external partner. Cross-company joint filing is not a common route to freedom-to-operate coverage in this field.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to well completion and intervention, with the prior art for and against each one.
Who holds the claim territory
The assignee ranking is dominated by a small set of oilfield-services majors and Chinese state petroleum entities, several of whose subsidiaries and research institutes file separately and co-assign back to the parent. None of the largest holders show filing growth in the latest recorded year.
Schlumberger's filing structure spans several legal entities
Schlumberger-affiliated assignees appear under several distinct corporate names in the ranking and co-file with each other at the highest pair strength in the dataset (36 shared families), reflecting a multi-entity IP structure rather than a single filer.
Sinopec files jointly with its internal engineering institutes
Sinopec's parent entity co-assigns repeatedly with its own petroleum engineering technology research institutes, indicating that R&D-institute-originated inventions are routed back through the corporate assignee for filing.
The largest historical filers have nearly stopped
Halliburton, Baker Hughes, Sinopec and PetroChina-affiliated assignees each show at most one filing in the latest recorded year, with several at zero and year-on-year drops of -50% to -100%. This is sector-wide deceleration, not a competitive vacuum being filled by a new entrant.
| Assignee | Recent year | YoY |
|---|---|---|
| Halliburton Energy Services, Inc. (USA) | 1 | -50% |
| PetroChina Company Limited | 0 | -100% |
| Schlumberger Technology Corporation | 0 | — |
| China Petroleum & Chemical Corporation (Sinopec) | 0 | -100% |
| Baker Hughes Holdings LLC | 0 | — |
| Schlumberger Technology LLC | 0 | — |
| ExxonMobil Upstream Research Company | 0 | — |
| Saudi Arabian Oil Company (Saudi Aramco) | 0 | -100% |
Where to take this analysis
The filing counts and rankings answer who and how much. The next questions are what specific claims block a given design and where a defensible first-filing position still exists.
Map claim scope against a specific design
Run a freedom-to-operate check on the highest-cited records against your own completion tool geometry, particularly where through-bore or flush-diameter claims overlap with coiled tubing deployment.
Explore claims in EurekaTrack the offices that matter now
Set up ongoing monitoring on Chinese and US receiving-office filings specifically, since together they account for the large majority of recent activity and either could originate a blocking claim first.
Set up monitoring in EurekaTest the under-claimed branches
Before investing in digital twin control or marine-integrated intervention systems, check current claim density in those specific IPC pockets rather than assuming the whole field is saturated.
Run a white space search in EurekaCommon questions on well completion and intervention patents
The ranking is led by a mix of major oilfield services companies and Chinese state petroleum entities, several of which file under multiple related legal-entity names that are grouped together in citation and co-assignment data. Schlumberger-affiliated entities and Sinopec-affiliated entities, including their internal research institutes, appear repeatedly and co-file with their own subsidiaries. No single assignee holds a dominant plurality of the 2,682 families in this dataset; the field is concentrated among a handful of large players rather than owned by one company.
No, filing activity peaked at 129 families in 2021 and has declined since, falling to 98 by 2022 and further in subsequent years. Some of the most recent years understate true filing activity because publication typically lags filing by around 18 months, so the very last data points should be read cautiously. Even accounting for that lag, the multi-year decline from the 2021 peak indicates a field that has stopped expanding its claim footprint at the pace it did in the late 2010s.
By receiving office, China leads with 816 filings, ahead of the United States at 635. Canada, WIPO under the PCT route, the European Patent Office and the United Kingdom follow at meaningfully lower volumes. This means a freedom-to-operate or white-space search limited to US and European offices will miss the largest current source of new filings in this technology.
USRE36723E1 is a reissued patent covering a spoolable coiled tubing completion system in which completion apparatus is built flush with the coiled tubing outside diameter, avoiding upsets while staying flexible enough to spool on a standard reel. Its through-bore design is wide enough to pass wireline tools for separate operations, and the system integrates a tubing retrievable safety valve, annular control valve, concentric gas lift valves, a zone packer, a landing nipple and a sliding sleeve, all usable with standard coiled tubing well control equipment in live wells. Anyone designing a flush-diameter, through-bore coiled tubing completion assembly with similar valve or packer integration should check this claim scope directly rather than assume it is expired boilerplate, given its reissue status.
The clearest gaps sit outside the dominant E21B hardware classification: digital control and monitoring for intelligent completions, cyclone-based downhole separation, marine-vessel-integrated intervention systems, and fluid-loss-control materials chemistry each register only in the low tens of records against the 2,648 in the core drilling-and-wells class. That imbalance suggests claim space around software-driven completion control and materials science is comparatively open, even though the physical hardware space is densely occupied. Any first filing in those adjacent branches should be checked against the specific IPC pockets rather than assumed to be open purely because the overall field looks saturated.
Research Well Completion and Intervention in depth with Eureka
Go past this page: query the whole well completion and intervention corpus yourself, in your own scope.
Every answer comes back with patent numbers you can open.
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.