Well Logging Patents: Who Leads, Where Filings Are Cooling 2026
- Filing has cooled since 2020. Annual filings peaked at 18 in 2020 and have declined since, with the midpoint year 2022 already down to 8 — a flat-to-declining trend, not a growing one.
- One family cluster dominates the field. The strongest co-assignee pairs are all Schlumberger-affiliated entities filing jointly, a pattern that points to a single corporate family holding a large, coordinated claim position.
- The largest incumbents show zero latest-year filings. Every top assignee tracked for recent-year momentum, including Halliburton (down 100% YoY) and Baker Hughes, shows no filings in the most recent year — consistent with publication lag, but also with a maturing claim base.
What this landscape covers
This dataset covers 600 patent families published between 2015 and mid-2026 that combine well logging, formation evaluation or wireline logging with core measurement techniques — resistivity, nuclear magnetic resonance (NMR) logging, porosity determination, borehole environment correction and interpretation modelling — under the IPC classes E21B47, G01V3 and G01V11. Filing offices span the United States, United Kingdom, Canada, the EPO, China and WIPO’s PCT route, reflecting a technology developed and litigated across multiple jurisdictions rather than concentrated in one.
Because publication typically lags filing by around 18 months, the last one to two years in any trend chart will look thinner than they eventually turn out to be. Read the recent-year dip alongside that lag, not as a definitive slowdown on its own.
Filing trends and technology composition
Two views of the same 600-family dataset: how filing volume has moved year over year, and which IPC subclasses carry the claim density.
A peak in 2020, then decline
Filings rose from 10 in 2017 to a peak of 18 in 2020, then eased back toward the high single digits by the early 2020s (8 at the 2022 midpoint) and continue trending down into the partial-year 2026 figure. This is a mature filing curve, not an emerging one.
G01V and E21B carry the bulk of the claims
G01V (geophysics and gravity surveying) appears in 532 of the 600 families and E21B (earth and rock drilling for wells) in 212, confirming this is fundamentally a downhole-measurement field. Smaller but non-trivial overlap with G01R (electric and magnetic measurement, 87), G06F (data processing, 43) and G01N (material analysis, 42) shows where logging interpretation increasingly leans on computation and lab-grade analysis techniques rather than sensor hardware alone.
Shares are the percentage of the 600 records in scope. A patent can carry several IPC classes, so the shares add up to more than 100%.
Go deeper on Well Logging and Formation Evaluation with Eureka
This page is one run against one query. Ask Eureka your own question about well logging and formation evaluation and every answer comes back with the patent numbers behind it.
Try EurekaThe most-cited prior art and a recent representative filing
Method for generating synthetic T1-T2 maps from marginal distributions of nuclear magnetic resonance logging tools (US12650535B2)
The method decomposes marginal distributions of T1 and T2 relaxation times into an initial sum of log-normal functions with matched amplitudes but different means and standard deviations, then fits those amplitudes, means and standard deviations so the sum reproduces the observed marginal distributions, producing a synthetic T1-T2 map from NMR logging tool data.Filed by Petróleo Brasileiro S.A. (Petrobras), published 2026-06-09 — one of the most recent grants in this dataset.
| # | Publication no. | Patent title | Citations |
|---|---|---|---|
| 1 | US5064006A | Downhole combination tool | 428 |
| 2 | US5498960A | NMR logging of natural gas in reservoirs | 407 |
| 3 | US5497087A | NMR logging of natural gas reservoirs | 369 |
| 4 | US5235285A | Well logging apparatus having toroidal induction antenna for measuring, while drilling, resistivity of earth … | 354 |
| 5 | US4899112A | Well logging apparatus and method for determining formation resistivity at a shallow and a deep depth | 307 |
| 6 | US5280243A | System for logging a well during the drilling thereof | 257 |
| 7 | US5230387A | Downhole combination tool | 257 |
| 8 | US5486762A | Apparatus including multi-wait time pulsed NMR logging method for determining accurate T2-distributions and a… | 240 |
| 9 | US4879463A | Method and apparatus for subsurface formation evaluation | 187 |
| 10 | US6229308B1 | Formation evaluation using magnetic resonance logging measurements | 181 |
Citation counts reflect influence within the searched corpus and skew toward older records; they are not a measure of current commercial relevance.
Each row carries its publication number; clicking a row searches Eureka by that number.
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Three patterns stand out once the family-level data is normalised: where claim density sits, how citations behave over time, and what the co-filing structure reveals about corporate consolidation.
Geophysical measurement claims are heavily occupied
With G01V present in the large majority of families and E21B in over a third, new filings aimed squarely at core resistivity or induction measurement are entering dense prior art. Differentiation is more likely at the interpretation-model or data-processing layer than at the raw sensor layer.
Influence rankings favour 1990s-era NMR and resistivity patents
The most-cited records in this corpus date from the early 1990s and cover foundational combination tools and NMR gas-detection methods. That reflects citation accumulation over three decades, not that those techniques remain the commercial frontier today.
The filing curve has turned down since its 2020 peak
Volume fell from a 2020 peak of 18 through a 2022 midpoint of 8, and the partial 2026 count is consistent with continued decline once the publication lag is accounted for. This looks like a field consolidating around existing claim positions rather than one attracting new entrants.
Co-filing concentrates inside one corporate family
All three of the strongest co-assignee pairs link Schlumberger-affiliated entities to one another, indicating that a large share of coordinated filing activity sits inside a single group's internal entity structure rather than across genuine industry partnerships.
Eureka can read the same corpus for gaps instead of for coverage: under-claimed branches adjacent to well logging and formation evaluation, with the prior art for and against each one.
Who holds the claim positions
Filing activity concentrates around a small number of large oilfield-services groups, with a long tail of smaller Chinese instrumentation firms and individual inventors filing narrower, single-purpose tools.
Schlumberger's entity structure dominates co-filing
Schlumberger Technology, Schlumberger Holdings, Schlumberger Canada and related entities appear repeatedly together across the strongest co-assignee pairs, consistent with a single group managing its portfolio across multiple jurisdictional filing entities.
Halliburton and Baker Hughes show no recent-year activity
Halliburton Energy Services shows a -100% year-on-year change and zero latest-year filings; Baker Hughes and Schlumberger's own principal entities show the same. This is likely amplified by publication lag but still marks a visible pause among the largest incumbents.
Smaller Chinese instrumentation firms fill the tail
Entities such as regional energy-technology institutes and county-level exploration-technology developers appear as single or low-count filers, typically around narrower borehole-instrumentation or measurement-tool claims rather than broad interpretation-model patents.
| Assignee | Recent year | YoY |
|---|---|---|
| Schlumberger Technology Corporation | 0 | — |
| Schlumberger Holdings Limited | 0 | — |
| Schlumberger Technology LLC | 0 | — |
| Halliburton Energy Services, Inc. (USA) | 0 | -100% |
| Baker Hughes Holdings LLC | 0 | — |
| Schlumberger Canada Limited | 0 | — |
| Schlumberger Limited | 0 | — |
| SCHLUMBERGER KK | 0 | — |
Where to take this analysis
The dataset points to a field where core measurement claims are dense but the interpretation and data-processing layer is comparatively open.
Map freedom-to-operate around the Schlumberger cluster
Given how much co-filing activity concentrates inside Schlumberger's entity structure, any new resistivity or NMR logging tool should be checked against that cluster's combined family before committing to a claim strategy.
Run a freedom-to-operate search in EurekaAssess the interpretation-model white space
G06F and G01N overlap with core logging IPCs at meaningfully lower counts than G01V and E21B, suggesting data-processing and material-analysis angles on formation evaluation are less crowded.
Explore adjacent IPC classes in EurekaTrack whether the 2026 dip is lag or a real slowdown
Zero latest-year filings across every major tracked assignee could reflect the roughly 18-month publication lag rather than an actual pause; revisit the trend once later filings publish.
Set a filing alert in EurekaCommon questions about well logging patents
Filing activity in this dataset concentrates heavily around Schlumberger's various filing entities, which also dominate the strongest co-assignee pairings, indicating coordinated portfolio management across multiple jurisdictional subsidiaries. Halliburton and Baker Hughes are the other major oilfield-services holders, though both show zero filings in the most recent tracked year. Beneath these incumbents sits a long tail of smaller Chinese instrumentation firms and individual inventors filing narrower, single-tool patents.
It is declining. Filings rose from 10 in 2017 to a peak of 18 in 2020, then fell to 8 by the 2022 midpoint and continued lower toward the partial 2026 count. Some of the most recent drop is an artefact of publication lag, since filings typically take about 18 months to publish, but the multi-year downward trend predates that lag window and looks like genuine consolidation rather than a data artefact.
Geophysics and gravity surveying claims (IPC class G01V) appear in 532 of the 600 families in this dataset, and earth and rock drilling claims (E21B) appear in 212, confirming the field centres on downhole measurement rather than surface processing alone. Smaller but meaningful overlaps with electric and magnetic measurement (G01R), digital data processing (G06F) and material analysis (G01N) show interpretation and computation becoming more prominent alongside the core sensor hardware.
US12650535B2, assigned to Petróleo Brasileiro S.A. (Petrobras) and published on 2026-06-09, covers a method for generating synthetic T1-T2 maps from marginal distributions produced by nuclear magnetic resonance logging tools. The method decomposes T1 and T2 relaxation-time distributions into sums of log-normal functions and fits their amplitudes, means and standard deviations to match observed data. It is one of the most recent grants in this dataset and sits in the NMR-interpretation branch of the field rather than in raw sensor hardware.
The comparatively thin overlap between core logging IPCs and G06F (data processing) or G01N (material analysis) suggests machine-learning-assisted interpretation models and cross-tool porosity reconciliation methods are less claim-dense than core resistivity or NMR sensor patents. Real-time borehole environment correction and T1-T2 map synthesis techniques, of the kind seen in the most recent Petrobras filing, also appear less crowded. These branches are worth checking specifically against the Schlumberger-linked cluster before filing, since that group's combined portfolio is the largest single claim block in the dataset.
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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.
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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.