Semisubmersible & Drillship Hull Patents: Leaders & White Space 2026
- Concentrated at the top. The five leading assignees hold 313 of 705 records in scope (44.4%), and the leading ten hold 58.4% — a field where a handful of shipyards and drilling contractors set the terms.
- Filings have pulled back hard from the 2017 peak. From 2021 to 2024, the last year that can be treated as complete, filings fell 84%, from 19 to 3 — a real contraction in new claim activity, not a data artefact.
- Hull and drilling classes dominate jointly. E21B (earth & rock drilling) appears on 73.8% of records and B63B (ships & marine vessels) on 43.1%, showing that most filings sit at the intersection of drilling function and hull structure rather than in either alone.
Filing growth compares 2021 (19 records) with 2024 (3) — 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 705 records in scope (CR5), not by the ranked leaders only.
What this landscape covers
This landscape tracks patent filings at the intersection of semisubmersible drilling units, drillships and column-stabilised units with the specific engineering problems that make them work offshore: heave response, variable deck load, ballast control, station keeping, moonpool design and pontoon buoyancy. It is a structural and operational landscape, not a generic drilling-rig one — a record only enters scope if it addresses both the vessel type and one of these load-handling or motion-control mechanisms.
The 705 records in scope span 2015 through the 2026 cut-off, with the United States, the European Patent Office and the PCT route carrying the largest share of receiving-office activity, followed by South Korea, the United Kingdom and Australia. That office mix reflects where hull design and drilling-contractor engineering work is actually filed and defended, not just where rigs operate.
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
Two views of the same 705-record dataset: how filing volume has moved year over year, and which IPC subclasses the records actually sit in.
Filings peaked in 2017 and have since fallen sharply
Filings reached a peak of 71 in 2017. From 2021 (19 filings) to 2024 (3 filings) — the last year that can be treated as complete given an 18-month publication lag — filings dropped 84%. Years after 2024 are still filling in and should not be read as continued decline.
Drilling and hull classes carry the field jointly
E21B (earth & rock drilling) appears on 73.8% of the 705 records and B63B (ships & marine vessels) on 43.1%. Smaller classes — pipe fittings, fluid flow control, marine propulsion, ship auxiliaries, non-electric control and pumps — each sit at or below 5.1%, marking the auxiliary systems that ride alongside the core hull and drilling claims rather than driving filing volume on their own.
Shares are the percentage of the 705 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Semisubmersible and Drillship Hulls with Eureka
This page is one run against one query. Ask Eureka your own question about semisubmersible and drillship hulls and every answer comes back with the patent numbers behind it.
Try EurekaA representative record: moonpool geometry on a drillship
Moonpool and drillship having the same
The moonpool includes a first space penetrating from the bottom surface through the upper deck of the drillship to carry out drilling operations, and a second space formed alongside the first space along the drillship's length, with the bottom of the second space open toward the lower side of the vessel. Extending the moonpool through this second space increases its overall length without a matching increase in deck footprint.Filed by Samsung Heavy Industries; illustrates the moonpool-geometry claim style common across drillship hull filings in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US4398487A | Fairing for elongated elements | 157 |
| 2 | US6155748A | Deep water riser flotation apparatus | 141 |
| 3 | US20050061546A1 | Method for pressurized mud cap and reverse circulation drilling from a floating drilling rig using a sealed m… | 114 |
| 4 | US7237623B2 | Method for pressurized mud cap and reverse circulation drilling from a floating drilling rig using a sealed m… | 113 |
| 5 | US5044672A | Metal-to-metal sealing pipe swivel joint | 112 |
| 6 | US20110300008A1 | Compact cable suspended pumping system for lubricator deployment | 107 |
| 7 | US6766860B2 | Multi-activity offshore drilling facility having a support for tubular string | 106 |
| 8 | US5439321A | Interruptive mobile production system | 103 |
| 9 | US6439936B1 | High retraction marine thruster | 94 |
| 10 | US4509448A | Quick disconnect/connect mooring method and apparatus for a turret moored drillship | 89 |
Citation counts favour older records simply because they have had longer to accumulate citations inside this corpus — treat them as a signal of influence on later filings, not of current commercial relevance.
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 numbers say about this field
Four read-outs from the dataset that matter for filing strategy and freedom-to-operate work.
A small group sets the claim baseline
The five leading assignees together hold 313 of the 705 records in scope, and the leading ten hold 58.4%. New entrants filing hull or ballast-control claims are almost certainly filing into space already occupied by these few players' portfolios.
Filing activity has contracted sharply
Filings fell from 19 in 2021 to 3 in 2024, the last year with complete data given the roughly 18-month publication lag. That is a real pullback in new claim activity from the 2017 peak of 71, not noise in the count.
Drilling function anchors most filings
E21B appears on 73.8% of the 705 records and B63B on 43.1%, confirming that most patents in scope combine a drilling-function claim with a hull or vessel claim rather than treating either in isolation.
Joint filing is rare and concentrated
Only ten co-assignee pairs appear across the dataset, with the strongest pairing appearing 15 times. Most filers in this field patent independently rather than through joint ventures, with the notable exception of one recurring shipyard-and-drilling-contractor pairing.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to semisubmersible and drillship hulls, with the prior art for and against each one.
Who holds the claim space, and where it thins out
The ranking covers 100 companies returned by the data endpoint — not a fixed top-50 or top-100 cut, just the whole ranked list this dataset produces. Filing counts run from a leader at 175 down through the fifth-ranked assignee at 25 and the tenth-ranked at 18, then into a long tail of single- and few-filing entrants.
One assignee dominates by volume
The leading assignee holds 175 of the 705 records in scope, well ahead of the fifth-place holder at 25 and the tenth-place holder at 18 — a steep drop-off rather than a gradual one.
A cluster of shipyards and drilling contractors
Between fifth and tenth place, filing counts sit in a narrow 18-to-25 band, pointing to a group of established shipbuilders and offshore contractors filing at a similar, steady pace rather than one runaway second player.
Many single- or few-filing entrants
Beyond the leading ten, the ranking extends to 100 companies, most holding only a handful of records each — a pattern consistent with engineering firms filing narrowly around one specific hull or ballast mechanism rather than building broad portfolios.
| Assignee | Recent year | YoY |
|---|---|---|
| Ensco International Inc. | 0 | — |
| Hanwha Ocean Co., Ltd. | 0 | — |
| A.P. Moller-Maersk | 0 | — |
| Fincantieri Oil & Gas S.p.A. | 0 | — |
| Samsung Heavy Industries Co., Ltd. | 0 | — |
| HD Hyundai Heavy Industries Co., Ltd. | 0 | — |
| ROTOJAR INNOVATIONS LIMITED | 0 | — |
| Rotojar Innovations Limited | 0 | — |
Where to take this analysis
The figures above establish the shape of the field. Turning that into a filing or freedom-to-operate decision means drilling into specific claims and specific assignees.
Check freedom-to-operate against the leading assignees
With 44.4% of records held by five assignees, any new hull, ballast or moonpool filing should be checked claim-by-claim against their granted portfolios before drafting.
Run an FTO search in Eureka →Track the under-claimed branches before they fill in
Sub-areas like active heave-compensated riser tensioning and closed-loop ballast control show lower filing density than the core hull classes — a narrowing window for a first-mover claim.
Explore white space in Eureka →Watch whether filing contraction continues past 2024
The 84% drop from 2021 to 2024 is confirmed, but 2025 and later years are still filling in behind the publication lag. Re-check the trend once those years mature.
Set a filing alert in Eureka →Common questions about semisubmersible and drillship hull patents
The dataset ranks 100 assignees by record count, with a single leader holding 175 of the 705 records in scope, well ahead of the fifth-ranked holder at 25 and the tenth-ranked holder at 18. The top five assignees together account for 44.4% of all records, and the top ten account for 58.4%. That steep drop-off from leader to fifth place means the field is best described as concentrated at the top with a long tail of smaller filers, rather than evenly split among a handful of comparable players.
Filings peaked at 71 in 2017 and fell to 3 by 2024, an 84% drop from the 2021 level of 19 filings. This pattern tracks the broader offshore drilling capital cycle, where new-build rig orders and associated hull engineering work slowed considerably after the mid-2010s downturn in oil and gas capital spending. It is worth noting that 2025 and 2026 figures are still incomplete because publication lags filing by roughly 18 months, so the true 2025 filing level will only become clear later.
The scope combines vessel-type terms — semisubmersible drilling unit, drillship, column-stabilised unit — with specific engineering mechanisms: heave response, variable deck load, ballast control systems, station keeping, moonpool design and pontoon buoyancy. In IPC terms, E21B (earth and rock drilling) appears on 73.8% of the 705 records and B63B (ships and marine vessels) on 43.1%, showing most filings claim both a drilling function and a hull or vessel structure together. Smaller classes covering pipe fittings, fluid control, propulsion, auxiliaries and pumps each appear on 5.1% or fewer records, marking narrower auxiliary-system claims.
Filing density is heaviest in the core drilling and hull classes, E21B and B63B, which together anchor most of the 705 records. Sub-areas that appear less frequently in the dataset — such as active heave-compensated riser tensioning, closed-loop ballast control tied to dynamic positioning, and pontoon buoyancy redistribution under variable deck load — carry comparatively lower filing density relative to those core classes. Lower density in a searched corpus is not proof a mechanism is unclaimed everywhere, but it does flag areas worth a closer freedom-to-operate check before committing to a first claim.
US20110197802A1, filed by Samsung Heavy Industries, claims a drillship moonpool with two adjoining spaces: a primary space penetrating the hull for drilling operations, and a second space alongside it that is open at the bottom, which together increase the effective moonpool length without expanding the deck footprint. It is included here as a representative record because its claim style — geometric moonpool configuration rather than a drilling-fluid or control-system claim — is common across drillship hull filings in this dataset. Anyone designing a moonpool layout with an extended or multi-part cavity should review it directly rather than relying on this summary alone.
Research Semisubmersible and Drillship Hulls in depth with Eureka
Go past this page: query the whole semisubmersible and drillship hulls 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.