E21B 33/061
Ram-type blow-out preventers
Official title: {Ram-type blow-out preventers, e.g. with pivoting rams}
E21B33/061 (Ram-type blow-out preventers) appears on 750 US grants and 680 published applications in this corpus.
Search patents in E21B- Granted patents
- 750
- Published applications
- 680
- Assignees
- 209
- Inventors
- 935
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 5 | 0 |
| 1978 | 3 | 0 |
| 1979 | 4 | 0 |
| 1980 | 9 | 0 |
| 1981 | 5 | 0 |
| 1982 | 7 | 0 |
| 1983 | 5 | 0 |
| 1984 | 7 | 0 |
| 1985 | 18 | 0 |
| 1986 | 6 | 0 |
| 1987 | 9 | 0 |
| 1988 | 2 | 0 |
| 1989 | 7 | 0 |
| 1990 | 11 | 0 |
| 1991 | 11 | 0 |
| 1992 | 3 | 0 |
| 1993 | 4 | 0 |
| 1994 | 7 | 0 |
| 1995 | 4 | 0 |
| 1996 | 5 | 0 |
| 1997 | 10 | 0 |
| 1998 | 8 | 0 |
| 1999 | 9 | 0 |
| 2000 | 10 | 0 |
| 2001 | 5 | 0 |
| 2002 | 4 | 6 |
| 2003 | 5 | 10 |
| 2004 | 6 | 13 |
| 2005 | 9 | 8 |
| 2006 | 11 | 17 |
| 2007 | 11 | 7 |
| 2008 | 9 | 21 |
| 2009 | 9 | 4 |
| 2010 | 12 | 12 |
| 2011 | 7 | 18 |
| 2012 | 10 | 30 |
| 2013 | 23 | 39 |
| 2014 | 29 | 34 |
| 2015 | 31 | 32 |
| 2016 | 35 | 58 |
| 2017 | 31 | 60 |
| 2018 | 50 | 52 |
| 2019 | 48 | 52 |
| 2020 | 47 | 44 |
| 2021 | 48 | 33 |
| 2022 | 29 | 36 |
| 2023 | 32 | 26 |
| 2024 | 29 | 29 |
| 2025 | 32 | 25 |
| 2026 | 18 | 14 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Automatic thrust activated multi-speed reduction gear and clutch system and method22 Sep 2026US 12,742,362 B2Schlumberger Technology Corporation
- Closing unit system for a blowout preventer8 Sep 2026US 12,729,597 B2Schlumberger Technology Corporation
- Apparatus for thermal activation of blow-out preventers of oil and gas wells11 Aug 2026US 12,704,038 B1Saudi Arabian Oil Company
- Energy delivery system for supplying hydraulic pressure for severing an intervention medium11 Aug 2026US 12,704,042 B2Halliburton Energy Services.Inc.
- Electrically-actuated blow-out preventer14 Jul 2026US 12,680,410 B2Schlumberger Technology Corporation
- Systems and methods for cutting coiled tubing strings at a wellsite24 Sep 2026US 2026/0286803 A1Grant Prideco, L.P.
- Blowout preventer quick connect bonnet system27 Aug 2026US 2026/0251031 A1Schlumberger Technology Corporation
- Intensifier ram blowout preventer20 Aug 2026US 2026/0243140 A1BOP Technologies, INC
- Annular Blow Out Preventer20 Aug 2026US 2026/0243141 A1SRI Energy, Inc.
- Bop pipe connection system16 Jul 2026US 2026/0201985 A1Kim Co., Ltd.
Most cited
By later US patents
- Subsea hydraulic choke193US 4,046,191 AExxon Production Research Company · 1977
- Marine riser well control method and apparatus160US 4,626,135 AHydril Company · 1986
- Method and apparatus for replacing BOP with gate valve121US 6,601,650 B2Worldwide Oilfield Machine, Inc. · 2003
- BOP with partially equalized ram shafts101US 5,735,502 AVarco Shaffer, Inc. · 1998
- Method and device for measuring a path that has been covered98US 7,302,842 B2Cameron International Corporation · 2007