Dual Gradient Systems, LLC
Records under this name other than patents Dual Gradient Systems, LLC holds now: patents now held by others, patents whose terms have ended, and its applications, pending or abandoned.
Back to Dual Gradient Systems, LLC
| Patent | Title | Status | Expires | Confidence |
|---|---|---|---|---|
| US 6,843,331 | Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications Term ended Term ended May 20, 2021 · From the USPTO record | Term ended | Term ended May 20, 2021 | From the USPTO record |
| US 8,393,403 | Drill string flow control valves and methods Formerly held Lapsed on the fee record Ended Mar 12, 2021 · From the USPTO record | Lapsed on the fee record | Ended Mar 12, 2021 | From the USPTO record |
| US 6,536,540 | Method and apparatus for varying the density of drilling fluids in deep water oil drilling applications Term ended Term ended Mar 10, 2021 · From the USPTO record | Term ended | Term ended Mar 10, 2021 | From the USPTO record |
| US 8,066,079 | Drill string flow control valves and methods Lapsed on the fee record Ended Nov 29, 2019 · From the USPTO record | Lapsed on the fee record | Ended Nov 29, 2019 | From the USPTO record |
| US 7,992,654 | Dual gradient drilling method and apparatus with an adjustable centrifuge Lapsed on the fee record Ended Aug 9, 2019 · From the USPTO record | Lapsed on the fee record | Ended Aug 9, 2019 | From the USPTO record |
| US 7,992,655 | Dual gradient drilling method and apparatus with multiple concentric drill tubes and blowout preventers Lapsed on the fee record Ended Aug 9, 2019 · From the USPTO record | Lapsed on the fee record | Ended Aug 9, 2019 | From the USPTO record |
| US 8,844,653 | Continuous circulating sub for drill strings Lapsed on the fee record Ended Sep 30, 2018 · From the USPTO record | Lapsed on the fee record | Ended Sep 30, 2018 | From the USPTO record |
| US 7,093,662 | System for drilling oil and gas wells using a concentric drill string to deliver a dual density mud Lapsed on the fee record Ended Aug 22, 2018 · From the USPTO record | Lapsed on the fee record | Ended Aug 22, 2018 | From the USPTO record |
| US 7,090,036 | System for drilling oil and gas wells by varying the density of drilling fluids to achieve near-balanced, underbalanced, or overbalanced drilling conditions Lapsed on the fee record Ended Aug 15, 2018 · From the USPTO record | Lapsed on the fee record | Ended Aug 15, 2018 | From the USPTO record |
| US 7,762,357 | Dual gradient drilling method and apparatus with an adjustable centrifuge Lapsed on the fee record Ended Jul 27, 2018 · From the USPTO record | Lapsed on the fee record | Ended Jul 27, 2018 | From the USPTO record |