Special core analysis (SCAL) covers laboratory measurements that go beyond routine porosity and permeability testing to characterise multiphase flow behaviour in reservoir rock, including relative permeability, capillary pressure curves, wettability index and residual oil saturation. It typically uses steady-state or centrifuge displacement methods, or spontaneous imbibition, to model how oil, gas and water move through the same rock sample under reservoir-like conditions. Routine core analysis, by contrast, measures single-phase properties like porosity and absolute permeability and is far less time- and cost-intensive. Patent filings in the SCAL space concentrate on measurement apparatus, test protocols and the software used to interpret the resulting curves.

Filing activity in this dataset is concentrated: the top 5 assignees together hold 49.6% of all 258 records in scope, and the top 10 hold 75.6%. The single leading assignee holds 37 records, well ahead of the fifth-placed company at 19 and tenth place at 12. This points to a field dominated by a handful of large oilfield-services and national-oil-company filers rather than a broad base of small specialist entrants, though the ranked list runs to 69 companies in total.

Publication typically lags the actual filing date by around 18 months, so any year close to the data cut-off will always show fewer records than were actually filed. In this dataset the 2026 figure is a single partial-year record, and several leading assignees show zero filings in the latest tracked year — that is a publication-lag effect, not evidence that activity in the field has stopped. The more reliable read is the completed-year trend, which peaked in 2018 at 31 records.