E21B 37/045
Free-piston scrapers
Official title: {Free-piston scrapers}
E21B37/045 (Free-piston scrapers) appears on 25 US grants and 22 published applications in this corpus.
Search patents in E21B- Granted patents
- 25
- Published applications
- 22
- Assignees
- 15
- Inventors
- 42
- Latest grant
- 12 Aug 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1990 | 2 | 0 |
| 1991 | 0 | 0 |
| 1992 | 0 | 0 |
| 1993 | 0 | 0 |
| 1994 | 0 | 0 |
| 1995 | 0 | 0 |
| 1996 | 0 | 0 |
| 1997 | 0 | 0 |
| 1998 | 1 | 0 |
| 1999 | 0 | 0 |
| 2000 | 1 | 0 |
| 2001 | 0 | 2 |
| 2002 | 1 | 3 |
| 2003 | 1 | 0 |
| 2004 | 1 | 1 |
| 2005 | 1 | 0 |
| 2006 | 0 | 1 |
| 2007 | 0 | 0 |
| 2008 | 1 | 0 |
| 2009 | 0 | 1 |
| 2010 | 1 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 0 | 1 |
| 2018 | 0 | 1 |
| 2019 | 0 | 4 |
| 2020 | 5 | 3 |
| 2021 | 4 | 3 |
| 2022 | 1 | 0 |
| 2023 | 3 | 0 |
| 2024 | 0 | 1 |
| 2025 | 2 | 1 |
By publication year. Applications have been published since 2001.
Recent patents
- Downhole apparatus12 Aug 2025US 12,385,327 B2Expro North Sea Limited
- Wiper dart having a bi-diameter wiper cup with protruding ring8 Apr 2025US 12,270,281 B2Halliburton Energy Services.Inc.
- Casing exit anchor with redundant activation system19 Sep 2023US 11,761,277 B2Baker Hughes Oilfield Operations LLC
- Scale sampler plunger22 Aug 2023US 11,732,552 B1Saudi Arabian Oil Company
- Cleaning assembly for magnet assemblies27 Jun 2023US 11,684,931 B2Jagtech AS
- Wiper dart having a bi-diameter wiper cup with protruding ring13 Mar 2025US 2025/0084732 A1Halliburton Energy Services.Inc.
- Downhole apparatus15 Feb 2024US 2024/0052712 A1Deltatek Oil Tools Limited
- Casing exit anchor with redundant activation system2 Dec 2021US 2021/0372211 A1Baker Hughes Oilfield Operations LLC
- Casing exit anchor with redundant activation system30 Sep 2021US 2021/0301610 A1Baker Hughes Oilfield Operations LLC
- Cleaning Assembly for Magnet Assemblies5 Aug 2021US 2021/0237099 A1Jagtech AS
Most cited
By later US patents
- Subsurface apparatus30US 6,722,442 B2Weatherford/Lamb, Inc. · 2004
- Bi-directional traction apparatus30US 6,953,086 B2Weatherford/Lamb, Inc. · 2005
- Method and system for cleaning well casing21US 4,896,720 AAtlantic Richfield Company · 1990
- Traction apparatus15US 6,460,616 B1Weatherford/Lamb, Inc. · 2002
- Retrievable pig14US 6,122,791 A2000