This dataset’s assignee ranking covers 30 companies, and the leading assignee holds 23 families, well ahead of the fifth-place holder at 17 and the tenth-place holder at 6. The names behind these totals are dominated by long-established oilfield-service groups with decades of wireline and formation-evaluation filing history, several of which appear under related corporate entities. That structure means genuine white space is more likely to be found by checking specific claim elements against the leader’s portfolio rather than assuming the field is fragmented.

The clean, comparable figure this dataset supports is a 33% rise in filings from 2021 to 2024, from 3 to 4 records. Filing counts for 2025 and 2026 look lower, but that is expected: publication typically lags actual filing by around 18 months, so recent years are always undercounted at the time a search is run. Read the 2021-2024 span as the reliable growth signal and treat anything after 2024 as still filling in rather than as a genuine decline.

US6470274B1 covers a tensorial dual water saturation model that derives laminar shale volume and sand conductivity from multi-component induction log data, combined with NMR-derived measurements of clay-bound water in shale and formation. It is the most-cited record in this dataset behind a small group of hydrocarbon-production patents, with 124 citations, making it a foundational reference point for laminated-reservoir saturation work. It does not block every saturation approach, but any model relying on tensorial resistivity components plus NMR clay-bound water measurement in laminated shaly sands should be checked against its specific claim language before filing.