34 patents currently held

Held is read from USPTO's recorded assignments; a transfer never recorded there does not appear.

The next term ends in Mar 2029. from the record

Free plan: 3 watched companies. Pro: unlimited.

Alerts on its grants, lapses and transfers.

Ending by 2030

Mar 2029

Next term end

Patent families

When these terms end

5 yrs10 yrs20 yrs

Held patents by the year their term ends

2026202720282029 2030 2031 203220332034 2035 2036 203720382039204020412042204320442045

notable patents fee due within 90 days all others Updated Nov 14, 2026 · includes USPTO assignment & status data published Nov 14, 2026 and grant & fee data published Nov 10, 2026 (weekly) · how we know

Notable: the highest-ranked patents in this portfolio by citations and family size. Fee due within 90 days: a maintenance fee is due within 90 days of when this page was computed and not yet paid.

Notable patents

Ranked by citations and family size, against patents of the same kind granted the same year. How we rank

Notable

Process of Removal of Hydrogen Sulfide in Downhole Oilfield Applications US 9,920,236

Cited by 15 later US patents, top 25% of utility patents granted in 2018 in our data, and renewed at every maintenance window due so far. Protection runs to 2032. A terminal disclaimer caps this term to an earlier patent's.

Ends Sep 2032 · Medium confidence Also notable

Solvent Composition and Process for Removal of Asphalt and Other Contaminant Materials US 11,053,464

Cited by 6 later US patents, top 25% of utility patents granted in 2021 in our data. Protection runs to 2034.

Ends Dec 2034 · High confidence Also notable

Sodium Nitrite Oxidation of Hydrogen Sulfide US 8,702,994

The largest patent family in this portfolio, 7 related applications, renewed at 3 of 3 maintenance windows. Protection runs to 2031.

Ends Oct 2031 · High confidence

Fee deadlines

Maintenance fees fall due 3.5, 7.5 and 11.5 years after grant. A missed fee ends a patent at the end of the six month grace period that follows, not on the due date.

1 fee due Jan 11, 2027
The maintenance fee for Solvent Composition and Process for Removal of Asphalt and Other Contaminant Materials (US 11,697,788) comes due Jan 11, 2027. Unpaid by Jul 12, 2027, it lapses early.
1 fee due Mar 12, 2027
The maintenance fee for Process for Decontamination of Hazardous Sulfur Compounds in Sour Water Tanks (US 11,753,320) comes due Mar 12, 2027. Unpaid by Sep 13, 2027, it lapses early.
1 fee due Apr 17, 2027
The maintenance fee for Solvent System for Cleaning Fixed Bed Reactor Catalyst in Situ (US 11,786,893) comes due Apr 17, 2027. Unpaid by Oct 18, 2027, it lapses early.
1 fee due Jun 26, 2027
The maintenance fee for Decontamination of Sulfur Contaminants from a Vessel (US 11,850,551) comes due Jun 26, 2027. Unpaid by Dec 27, 2027, it lapses early.
1 fee due Jul 7, 2027
The maintenance fee for Process for Removal of Hydrogen Sulfide in Downhole Oilfield Applications (US 10,526,527) comes due Jul 7, 2027. Unpaid by Jan 7, 2028, it lapses early.
1 fee due Sep 10, 2027
The maintenance fee for Decontamination of Sulfur Contaminants from a Vessel (US 10,583,392) comes due Sep 10, 2027. Unpaid by Mar 10, 2028, it lapses early.
1 fee due Oct 2, 2027
The maintenance fee for Solvent Composition and Process for Removal of Asphalt and Other Contaminant Materials (US 11,946,021) comes due Oct 2, 2027. Unpaid by Apr 3, 2028, it lapses early.

Which patents, and when each one lapses · Pro

Recent changes

Nothing was recorded against this company's patents in the last 90 days.

What they patent

The 5 largest of its 11 families, grouped by real patent family and labeled by the earliest filing in each. No technology classification is inferred from titles.

Sodium Nitrite Oxidation of Hydrogen Sulfide	6 in force	to Oct 2031
Process for Decontamination of Hazardous Sulfur Compounds in Sour Water Tanks	5 in force	to Oct 2032
Decontamination of Sulfur Contaminants from a Vessel	4 in force	to Apr 2036
Decontamination of Sulfur Contaminants from Hydrocarbons	4 in force	to Dec 2035
Solvent Composition and Process for Removal of Asphalt and Other Contaminant Materials	3 in force	to Dec 2034

Patents held now

Soonest term end first.

Patent	Title	Status	Expires	Confidence
US 9,682,878	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Term ends Mar 31, 2029 · High confidence	In force	Term ends Mar 31, 2029	High confidence
US 10,065,874	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Term ends Mar 31, 2029 · High confidence	In force	Term ends Mar 31, 2029	High confidence
US 10,723,641	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Term ends Mar 31, 2029 · High confidence	In force	Term ends Mar 31, 2029	High confidence
US 11,383,994	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Term ends Mar 31, 2029 · High confidence	In force	Term ends Mar 31, 2029	High confidence
US 12,391,588	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Ends no later than May 5, 2030 · Medium confidence	In force	Ends no later than May 5, 2030	Medium confidence
US 8,419,948	Wastewater Treatment In force Term ends Aug 24, 2030 · High confidence	In force	Term ends Aug 24, 2030	High confidence
US 9,505,641	Process for Decontamination of Hazardous Sulfur Compounds in Sour Water Tanks In force Term ends Jun 13, 2031 · High confidence	In force	Term ends Jun 13, 2031	High confidence
US 8,702,994	Sodium Nitrite Oxidation of Hydrogen Sulfide In force Term ends Oct 3, 2031 · High confidence	In force	Term ends Oct 3, 2031	High confidence
US 11,242,265	Process for Decontamination of Hazardous Sulfur Compounds in Oilfield Produced Waters In force Term ends Nov 7, 2031 · High confidence	In force	Term ends Nov 7, 2031	High confidence
US 10,526,527	Process for Removal of Hydrogen Sulfide in Downhole Oilfield Applications In force Term ends Feb 21, 2032 · Medium confidence	In force	Term ends Feb 21, 2032	Medium confidence

10 of 34 patents shown.

Pro members see all 34.

Pro members: see all 34 patents

Also on record, not counted in the 34: 7 applications pending. List them

Sources and methods

Compiled from USPTO application file histories, grants and recorded assignments, with the company's own names reviewed by hand. How this record was built

Portfolio grouped automatically from ownership conveyances to the names matched to this company, usually every name that begins with its own, so it counts patents an affiliate holds; each list row names the holder of record. Security interests are excluded and ambiguous records are not reviewed by hand.

Fee due within 90 days marks a patent with a maintenance fee due within 90 days of the date this page was computed and not yet recorded paid, so it can end earlier than the bar shows. A fee left unpaid ends the patent at the close of the six month grace period that follows its due date, not on the due date itself. It is not a prediction that the fee will be missed.

Computed patent terms end on the dates shown. Related patents and pending applications may cover overlapping subject matter.

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Zymeflow, Inc.