E21B 21/08
Controlling or monitoring pressure or flow of drilling fluid
Official title: Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure (valve arrangements therefor E21B21/10)
E21B21/08 (Controlling or monitoring pressure or flow of drilling fluid) appears on 1,721 US grants and 1,763 published applications in this corpus.
Search patents in E21B- Granted patents
- 1,721
- Published applications
- 1,763
- Assignees
- 483
- Inventors
- 3,016
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 8 | 0 |
| 1977 | 6 | 0 |
| 1978 | 6 | 0 |
| 1979 | 5 | 0 |
| 1980 | 5 | 0 |
| 1981 | 12 | 0 |
| 1982 | 4 | 0 |
| 1983 | 6 | 0 |
| 1984 | 8 | 0 |
| 1985 | 10 | 0 |
| 1986 | 10 | 0 |
| 1987 | 7 | 0 |
| 1988 | 9 | 0 |
| 1989 | 10 | 0 |
| 1990 | 5 | 0 |
| 1991 | 11 | 0 |
| 1992 | 7 | 0 |
| 1993 | 8 | 0 |
| 1994 | 9 | 0 |
| 1995 | 2 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 6 | 0 |
| 1999 | 13 | 0 |
| 2000 | 13 | 0 |
| 2001 | 18 | 6 |
| 2002 | 21 | 18 |
| 2003 | 18 | 31 |
| 2004 | 19 | 50 |
| 2005 | 30 | 28 |
| 2006 | 24 | 36 |
| 2007 | 41 | 30 |
| 2008 | 18 | 32 |
| 2009 | 15 | 47 |
| 2010 | 32 | 29 |
| 2011 | 27 | 50 |
| 2012 | 35 | 54 |
| 2013 | 42 | 65 |
| 2014 | 45 | 79 |
| 2015 | 55 | 80 |
| 2016 | 63 | 92 |
| 2017 | 60 | 94 |
| 2018 | 79 | 79 |
| 2019 | 86 | 89 |
| 2020 | 96 | 138 |
| 2021 | 138 | 153 |
| 2022 | 143 | 104 |
| 2023 | 134 | 127 |
| 2024 | 128 | 113 |
| 2025 | 99 | 81 |
| 2026 | 75 | 58 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Depth activated downhole adjustable bend assemblies22 Sep 2026US 12,742,360 B2National Oilwell Varco, L. P.
- Integrated line system for a mineral extraction system15 Sep 2026US 12,735,951 B2Schlumberger Technology Corporation
- Calculating pull for a stuck drill string15 Sep 2026US 12,735,953 B2Landmark Graphics Corporation
- Wellbore tripping advisor15 Sep 2026US 12,735,979 B2Schlumberger Technology Corporation
- Jetting system for drilling operations8 Sep 2026US 12,729,588 B1Saudi Arabian Oil Company
- Drilling in hot zones on coiled tubing8 Oct 2026US 2026/0309004 A1Eavor Technologies Inc.
- Temperature management of downhole tools8 Oct 2026US 2026/0309023 A1Eavor Technologies Inc.
- De-risking subsurface fluid prospects1 Oct 2026US 2026/0299151 A1Schlumberger Technology Corporation
- Drilling a multilateral closed-loop geothermal well24 Sep 2026US 2026/0286781 A1Eavor Technologies Inc.
- Method for obtaining measurement and logging while drilling survey in adverse conditions24 Sep 2026US 2026/0286828 A1MS Directional, LLC
Most cited
By later US patents
- Drilling systems with sensors for determining properties of drilling fluid downhole402US 6,176,323 B1Baker Hughes Incorporated · 2001
- Method and apparatus for deepwater drilling283US 4,813,495 AConoco Inc. · 1989
- Method and system for drilling and completing underbalanced multilateral wells utilizing a dual string technique in a live well205US 6,065,550 A2000
- Subsea hydraulic choke193US 4,046,191 AExxon Production Research Company · 1977
- Drilling fluid bypass for marine riser193US 4,291,772 AStandard Oil Company (Indiana) · 1981