This landscape covers patents combining solvent injection mechanisms — such as vapour/vapor extraction and expanding-solvent SAGD (ES-SAGD) — with the operational problems that determine whether those processes are economic, including solvent retention, asphaltene deposition, surface solvent recovery and solvent-steam ratio control. It excludes pure steam-only thermal recovery patents that do not reference a solvent component. The 79 records in this dataset were matched against a search string requiring both a recovery-mechanism term and an operational-problem term.

The ranking in this dataset covers 25 companies, with the leading assignee holding 27 records versus 9 at fifth place and 1 at tenth — a steep concentration rather than an even spread. Major oilfield-service and oil-sands operating companies dominate the ranked list. This is the full ranking the dataset returns, not a truncated top-list, so no filer outside these 25 appears with a comparable volume.

Filing volume ran from 8 records in 2017 to a peak of 13 in 2018, then declined toward 0 in the most recently complete comparison years, 2021 to 2024, a -100% change over that span. However, patent publication typically lags actual filing by around 18 months, so 2025 and 2026 figures in the underlying data are still incomplete and should not be read as confirmation that R&D activity has stopped. A clearer picture of the true current trend will only be available once those later years finish publishing.

US20150083413A1, filed by ConocoPhillips and published in 2015, addresses reducing solvent retention specifically within Expanding Solvent-Steam Assisted Gravity Drainage (ES-SAGD) operations, framing solvent retention reduction as a process-economics lever. It sits inside the same E21B-dominated claim space that covers the large majority of records in this dataset, meaning new ES-SAGD process filings should be checked against it specifically for overlap on solvent-retention control methods. It does not, on its own, cover the broader vapour-extraction or surface solvent recovery branches, which are separately claimed elsewhere in the dataset.

The technology composition shows heavy concentration in E21B (93.7% of the 79 records) and C09K (24.1%), with much thinner coverage in areas like dilution viscosity reduction chemistry, real-time chamber growth rate monitoring, and asphaltene deposition mitigation additives. These thinner branches are candidates for new claims because the core mechanical and wellbore process space is already densely occupied by the leading assignees. A first claim in one of these branches would need to tie a specific measurable trigger, such as a chamber growth rate threshold, to a concrete control action rather than restating the general ES-SAGD process.