E21B 34/142
Unsupported or free-falling elements
Official title: {unsupported or free-falling elements, e.g. balls, plugs, darts or pistons}
E21B34/142 (Unsupported or free-falling elements) appears on 950 US grants and 973 published applications in this corpus.
Search patents in E21B- Granted patents
- 950
- Published applications
- 973
- Assignees
- 262
- Inventors
- 1,336
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 2 | 0 |
| 1978 | 4 | 0 |
| 1979 | 2 | 0 |
| 1980 | 2 | 0 |
| 1981 | 3 | 0 |
| 1982 | 3 | 0 |
| 1983 | 3 | 0 |
| 1984 | 8 | 0 |
| 1985 | 4 | 0 |
| 1986 | 3 | 0 |
| 1987 | 6 | 0 |
| 1988 | 3 | 0 |
| 1989 | 3 | 0 |
| 1990 | 3 | 0 |
| 1991 | 5 | 0 |
| 1992 | 2 | 0 |
| 1993 | 2 | 0 |
| 1994 | 6 | 0 |
| 1995 | 1 | 0 |
| 1996 | 6 | 0 |
| 1997 | 1 | 0 |
| 1998 | 15 | 0 |
| 1999 | 6 | 0 |
| 2000 | 5 | 0 |
| 2001 | 9 | 2 |
| 2002 | 7 | 4 |
| 2003 | 7 | 6 |
| 2004 | 14 | 12 |
| 2005 | 3 | 5 |
| 2006 | 12 | 11 |
| 2007 | 1 | 12 |
| 2008 | 8 | 10 |
| 2009 | 9 | 15 |
| 2010 | 17 | 22 |
| 2011 | 9 | 41 |
| 2012 | 20 | 46 |
| 2013 | 22 | 69 |
| 2014 | 43 | 65 |
| 2015 | 48 | 77 |
| 2016 | 59 | 67 |
| 2017 | 48 | 54 |
| 2018 | 62 | 49 |
| 2019 | 74 | 57 |
| 2020 | 56 | 62 |
| 2021 | 64 | 66 |
| 2022 | 63 | 55 |
| 2023 | 53 | 55 |
| 2024 | 60 | 45 |
| 2025 | 45 | 37 |
| 2026 | 35 | 29 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Operating downhole wellbore valves15 Sep 2026US 12,735,957 B1Saudi Arabian Oil Company
- Dart and clutch assembly15 Sep 2026US 12,735,962 B2Epic Lift Systems
- Systems and methods for activating a pressure-sensitive downhole tool18 Aug 2026US 12,709,953 B2Robertson Intellectual Properties, LLC
- Actuation device for actuating a target sleeve valve assembly, and related systems and methods18 Aug 2026US 12,709,961 B2ExxonMobil Technology and Engineering Company
- Sand screen joint with producible check ball11 Aug 2026US 12,704,041 B2Halliburton Energy Services.Inc.
- Apparatus for recovering debris from a wellbore8 Oct 2026US 2026/0308994 A1Grant Prideco, L.P.
- System for delayed dissolution of downhole balls8 Oct 2026US 2026/0309002 A1Tenax Energy Systems, LLC
- Methods and systems for performing hydraulic fracturing operations8 Oct 2026US 2026/0309013 A1ExxonMobil Technology and Engineering Company
- Hydraulic fracturing method using lightweight proppant particles to reduce erosion and improve conductivity8 Oct 2026US 2026/0309016 A1ExxonMobil Technology and Engineering Company
- Sleeve assemblies and related completion systems and methods27 Aug 2026US 2026/0251036 A1Kobold Corporation
Most cited
By later US patents
- Downhole surge pressure reduction system and method of use340US 5,960,881 AJerry P. Allamon · 1999
- Multiple-set downhole tool and method210US 4,893,678 ATam International, Inc. · 1990
- Circulation tool193US 6,253,861 B1Specialised Petroleum Services Limited · 2001
- Method and apparatus for downhole fluid blast cleaning of oil well casing191US 5,797,454 ASonoma Corporation · 1998
- Downhole valve for oil/gas well187US 5,499,687 A1996