E21B 31/20
Gripping internally
Official title: gripping internally, e.g. fishing spears
E21B31/20 (Gripping internally) appears on 248 US grants and 186 published applications in this corpus.
Search patents in E21B- Granted patents
- 248
- Published applications
- 186
- Assignees
- 111
- Inventors
- 399
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 6 | 0 |
| 1978 | 4 | 0 |
| 1979 | 0 | 0 |
| 1980 | 3 | 0 |
| 1981 | 5 | 0 |
| 1982 | 1 | 0 |
| 1983 | 1 | 0 |
| 1984 | 1 | 0 |
| 1985 | 0 | 0 |
| 1986 | 4 | 0 |
| 1987 | 5 | 0 |
| 1988 | 3 | 0 |
| 1989 | 4 | 0 |
| 1990 | 2 | 0 |
| 1991 | 8 | 0 |
| 1992 | 5 | 0 |
| 1993 | 3 | 0 |
| 1994 | 1 | 0 |
| 1995 | 1 | 0 |
| 1996 | 1 | 0 |
| 1997 | 4 | 0 |
| 1998 | 4 | 0 |
| 1999 | 3 | 0 |
| 2000 | 5 | 0 |
| 2001 | 3 | 1 |
| 2002 | 4 | 1 |
| 2003 | 4 | 5 |
| 2004 | 5 | 6 |
| 2005 | 2 | 5 |
| 2006 | 4 | 6 |
| 2007 | 5 | 4 |
| 2008 | 2 | 2 |
| 2009 | 5 | 2 |
| 2010 | 5 | 10 |
| 2011 | 4 | 4 |
| 2012 | 5 | 6 |
| 2013 | 3 | 3 |
| 2014 | 3 | 10 |
| 2015 | 6 | 8 |
| 2016 | 8 | 11 |
| 2017 | 7 | 9 |
| 2018 | 13 | 11 |
| 2019 | 13 | 8 |
| 2020 | 11 | 11 |
| 2021 | 14 | 16 |
| 2022 | 14 | 13 |
| 2023 | 12 | 10 |
| 2024 | 6 | 11 |
| 2025 | 7 | 6 |
| 2026 | 7 | 7 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Recoverable fishing tool6 Oct 2026US 12,753,669 B1Saudi Arabian Oil Company
- Axial position-controlled operation toolstring and method8 Sep 2026US 12,729,595 B2Archer Oiltools AS
- Hydraulic actuated tool catcher25 Aug 2026US 12,716,329 B2Schlumberger Technology Corporation
- Methods and apparatus for casing recovery14 Jul 2026US 12,680,408 B2Ardyne Holdings Limited
- Downhole wireline recovery tool and method of recovering downhole wirelines7 Jul 2026US 12,674,367 B2Saudi Arabian Oil Company
- Downhole tool with cone assembly1 Oct 2026US 2026/0298046 A1Welltec A/S
- Casing running tool multi-gripper10 Sep 2026US 2026/0266145 A1Nabors Drilling Technologies USA, Inc.
- Tool for the recovery of a casing hanger from a wellhead10 Sep 2026US 2026/0266154 A1Aker Solutions Subsea AS
- Hydraulic actuated tool catcher4 Jun 2026US 2026/0153012 A1Schlumberger Technology Corporation
- Tubing anchor catcher operated by mandrel axial movement7 May 2026US 2026/0125961 A1
Most cited
By later US patents
- Method of extracting a hollow unit laid in the ground195US 5,984,582 A1999
- Technique for running casing139US 4,100,968 A1978
- Tubular running tool138US 6,309,002 B1Frank's Casing Crew and Rental Tools, Inc. · 2001
- Variable outside diameter tool for use in pikewells135US 4,842,082 ASmith International (North Sea) Limited · 1989
- Tubular running tool131US 6,431,626 B1Frankis Casing Crew and Rental Tools, Inc. · 2002