Zonal Isolation Patents: Who Leads, Where the Gaps Are 2026
Zonal isolation and cement evaluation patents: who holds the claim space and where it opens up
86.4% concentration. The top five assignees alone account for 2,008 of the 2,325 records in scope — a field with almost no middle tier between the leaders and a long tail. Annual filings rose from 101 in 2017 to a peak of 106 in 2022, then eased to 35 by 2024 — a complete-year decline of 31% from the 2021 level of 51. 2025 and 2026 counts are still filling in as publication catches up with filing, so they should not be read as a continued drop.
- 1HALLIBURTON ENERGY SERVICES INC1,630
- 2SCHLUMBERGER TECHNOLOGY BV121
- 3SCHLUMBERGER TECH CORP102
- 4SAUDI ARABIAN OIL CO78
- 5SERVICES PETROLIERS SCHLUMBERGER SA77
See the full zonal isolation and cement evaluation analysis in Eureka
- The complete ranking, not just the top five
- Every IPC branch with its share of the corpus
- The most-cited records, and where claim space is still thin
Common questions on this landscape
Who holds the most patents in zonal isolation and cement evaluation?
One assignee dominates this dataset, holding 1,630 of the 2,325 records in scope, far ahead of the next four combined. The top five assignees together account for 86.4% of all records, and the top ten reach 96.6%, leaving very little share for the remaining ranked companies. This concentration reflects how the field grew around a small number of large oilfield service companies rather than a broad base of independent inventors.
Is patent filing in this field growing or shrinking?
Filings peaked at 106 in 2022 and had fallen to 35 by 2024, a 31% decline from the 2021 level of 51. That said, 2025 and 2026 figures are still incomplete because publication typically lags filing by about 18 months, so the most recent years understate real activity. Based on the last fully comparable years, filing volume has cooled from its 2022 high rather than stopped.
What technology areas are most heavily claimed in cement evaluation patents?
Cement and treatment-fluid chemistry (IPC class C09K) appears in 62.1% of the 2,325 records, and earth and rock drilling methods (E21B) in 55.7%, making these the densest claim areas. Cement and ceramics materials (C04B) follow at 44.4%. By contrast, classes tied to sensing, geophysical analysis and data processing each cover under 5% of records, indicating that the evaluation and monitoring side of the field carries far less claim density than the chemistry and hardware side.
Disclaimer. This analysis is based on Patsnap Eureka data drawn from a limited snapshot of global patent records and is provided for general information and reference only. Patent data carries inherent limitations — recent filings are under-counted because of publication lag, counts may be on a record or family basis, classification and applicant-name data may contain errors or duplicates, and the underlying search query defines the scope shown — so the analysis may be incomplete or inaccurate and may not reflect the full technology landscape.
Nothing here is an exhaustive prior-art, novelty, freedom-to-operate or validity search, nor does it constitute legal, financial or professional advice, and it should not be relied upon as such. Verify independently and review with qualified patent and legal professionals before acting on it.
Method: Filing trend and technology composition. Derived from a Patsnap search on Zonal Isolation and Cement Evaluation covering 2015–2026, data cut-off 2026-07-31. Counts reflect published records only and shift as new filings publish. Every share divides by all records in scope. Data: Patsnap Eureka. See the full landscape report.