E21B 37/04
Operated by fluid pressure
Official title: operated by fluid pressure, e.g. free-piston scrapers
E21B37/04 (Operated by fluid pressure) appears on 108 US grants and 84 published applications in this corpus.
Search patents in E21B- Granted patents
- 108
- Published applications
- 84
- Assignees
- 61
- Inventors
- 197
- Latest grant
- 21 Apr 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1977 | 2 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 1 | 0 |
| 1984 | 0 | 0 |
| 1985 | 0 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 0 | 0 |
| 1989 | 2 | 0 |
| 1990 | 4 | 0 |
| 1991 | 2 | 0 |
| 1992 | 2 | 0 |
| 1993 | 3 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 2 | 0 |
| 1999 | 1 | 0 |
| 2000 | 1 | 0 |
| 2001 | 2 | 2 |
| 2002 | 2 | 3 |
| 2003 | 1 | 0 |
| 2004 | 3 | 2 |
| 2005 | 1 | 1 |
| 2006 | 0 | 3 |
| 2007 | 0 | 2 |
| 2008 | 1 | 1 |
| 2009 | 1 | 2 |
| 2010 | 2 | 4 |
| 2011 | 2 | 2 |
| 2012 | 3 | 1 |
| 2013 | 2 | 3 |
| 2014 | 2 | 1 |
| 2015 | 2 | 0 |
| 2016 | 0 | 1 |
| 2017 | 3 | 2 |
| 2018 | 1 | 7 |
| 2019 | 3 | 4 |
| 2020 | 8 | 8 |
| 2021 | 9 | 12 |
| 2022 | 7 | 10 |
| 2023 | 13 | 6 |
| 2024 | 5 | 3 |
| 2025 | 6 | 3 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Apparatus for verifying the inner diameter of tubulars forming a tubular string21 Apr 2026US 12,607,115 B2
- Downhole cleaning tool and method6 Jan 2026US 12,516,590 B2Coretrax Global Limited
- Rotary tool hydraulic power system21 Oct 2025US 12,448,859 B2Schlumberger Technology Corporation
- Clean up and actuation tool, method, and system30 Sep 2025US 12,428,933 B1Baker Hughes Oilfield Operations LLC
- Method and apparatus, including hose reel, for cleaning an oil and gas well riser assembly23 Sep 2025US 12,421,827 B1Tri-State Environmental, LLC
- Spinning diamond broach12 Feb 2026US 2026/0043311 A1Tally Production Systems, LLC
- Clean up and actuation tool, method, and system2 Oct 2025US 2025/0305390 A1Baker Hughes Oilfield Operations LLC
- Rotary tool hydraulic power system13 Mar 2025US 2025/0084716 A1Schlumberger Technology Corporation
- Wiper dart having a bi-diameter wiper cup with protruding ring13 Mar 2025US 2025/0084732 A1Halliburton Energy Services.Inc.
- Downhole cleaning tool and method19 Dec 2024US 2024/0418058 A1Coretrax Global Limited
Most cited
By later US patents
- Apparatus and methods for cleaning a well128US 4,919,204 AOtis Engineering Corporation · 1990
- Borehole cleaning apparatus and method37US 6,745,839 B1Weatherford/Lamb, Inc. · 2004
- Subsurface apparatus30US 6,722,442 B2Weatherford/Lamb, Inc. · 2004
- Bi-directional traction apparatus30US 6,953,086 B2Weatherford/Lamb, Inc. · 2005
- Indicating ball catcher28US 5,127,472 AHalliburton Company · 1992