E21B 31/00
Fishing for or freeing objects in boreholes or wells
E21B31/00 (Fishing for or freeing objects in boreholes or wells) appears on 1,484 US grants and 1,159 published applications in this corpus.
Search patents in E21B- Granted patents
- 1,484
- Published applications
- 1,159
- Assignees
- 463
- Inventors
- 2,054
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 13 | 0 |
| 1977 | 23 | 0 |
| 1978 | 21 | 0 |
| 1979 | 5 | 0 |
| 1980 | 19 | 0 |
| 1981 | 21 | 0 |
| 1982 | 9 | 0 |
| 1983 | 11 | 0 |
| 1984 | 21 | 0 |
| 1985 | 21 | 0 |
| 1986 | 16 | 0 |
| 1987 | 20 | 0 |
| 1988 | 9 | 0 |
| 1989 | 23 | 0 |
| 1990 | 12 | 0 |
| 1991 | 22 | 0 |
| 1992 | 21 | 0 |
| 1993 | 19 | 0 |
| 1994 | 11 | 0 |
| 1995 | 24 | 0 |
| 1996 | 14 | 0 |
| 1997 | 18 | 0 |
| 1998 | 16 | 0 |
| 1999 | 23 | 0 |
| 2000 | 15 | 0 |
| 2001 | 20 | 10 |
| 2002 | 23 | 15 |
| 2003 | 20 | 19 |
| 2004 | 17 | 27 |
| 2005 | 16 | 30 |
| 2006 | 22 | 22 |
| 2007 | 23 | 24 |
| 2008 | 16 | 20 |
| 2009 | 16 | 34 |
| 2010 | 20 | 34 |
| 2011 | 20 | 27 |
| 2012 | 28 | 46 |
| 2013 | 31 | 47 |
| 2014 | 40 | 39 |
| 2015 | 41 | 54 |
| 2016 | 37 | 65 |
| 2017 | 45 | 67 |
| 2018 | 62 | 62 |
| 2019 | 74 | 67 |
| 2020 | 76 | 86 |
| 2021 | 82 | 75 |
| 2022 | 86 | 70 |
| 2023 | 65 | 74 |
| 2024 | 69 | 65 |
| 2025 | 67 | 45 |
| 2026 | 41 | 35 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- E21B 31/12Grappling tools562
- E21B 31/107Fishing for or freeing objects in boreholes or wells: using impact means415
- E21B 31/005Fishing for or freeing objects in boreholes or wells: using vibrating or198
- E21B 31/035Controlling differential pipe sticking96
- E21B 31/06Fishing for or freeing objects in boreholes or wells: using magnetic means77
- E21B 31/03Freeing by flushing70
- E21B 31/002Destroying the objects to be fished54
- E21B 31/08Fishing for or freeing objects in boreholes or wells: using junk baskets46
All 9 subgroupsShow fewer
Recent patents
- Recoverable fishing tool6 Oct 2026US 12,753,669 B1Saudi Arabian Oil Company
- Calculating pull for a stuck drill string15 Sep 2026US 12,735,953 B2Landmark Graphics Corporation
- Axial position-controlled operation toolstring and method8 Sep 2026US 12,729,595 B2Archer Oiltools AS
- On-demand vibration tool for drilling applications1 Sep 2026US 12,723,483 B2Dynomax Drilling Tools Inc.
- Logging tool1 Sep 2026US 12,723,484 B2Saudi Arabian Oil Company
- Downhole apparatus for oscillating a tubular string8 Oct 2026US 2026/0308989 A1Grant Prideco, L.P.
- Apparatus for recovering debris from a wellbore8 Oct 2026US 2026/0308994 A1Grant Prideco, L.P.
- Bi-directional Running Tool for Expandable Liner Hanger8 Oct 2026US 2026/0309007 A1Halliburton Energy Services.Inc.
- Downhole tool with cone assembly1 Oct 2026US 2026/0298046 A1Welltec A/S
- Advancing a tubular string in a wellbore24 Sep 2026US 2026/0286800 A1
Most cited
By later US patents
- Well casing flotation device and method259US 5,181,571 AUnion Oil Company of California · 1993
- Method of extracting a hollow unit laid in the ground195US 5,984,582 A1999
- Downhole anchoring tools conveyed by non-rigid carriers190US 6,315,043 B1Schlumberger Technology Corporation · 2001
- Downhole valve for oil/gas well187US 5,499,687 A1996
- Apparatus and method for performing imaging and downhole operations at a work site in wellbores165US 6,041,860 ABaker Hughes Incorporated · 2000