E21B 33/04
Casing heads
Official title: Casing heads; Suspending casings or tubings in well heads
E21B33/04 (Casing heads) appears on 2,068 US grants and 1,536 published applications in this corpus.
Search patents in E21B- Granted patents
- 2,068
- Published applications
- 1,536
- Assignees
- 424
- Inventors
- 2,355
- Latest grant
- 22 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 13 | 0 |
| 1977 | 16 | 0 |
| 1978 | 15 | 0 |
| 1979 | 9 | 0 |
| 1980 | 8 | 0 |
| 1981 | 23 | 0 |
| 1982 | 23 | 0 |
| 1983 | 22 | 0 |
| 1984 | 20 | 0 |
| 1985 | 25 | 0 |
| 1986 | 27 | 0 |
| 1987 | 30 | 0 |
| 1988 | 33 | 0 |
| 1989 | 35 | 0 |
| 1990 | 41 | 0 |
| 1991 | 34 | 0 |
| 1992 | 29 | 0 |
| 1993 | 30 | 0 |
| 1994 | 30 | 0 |
| 1995 | 27 | 0 |
| 1996 | 17 | 0 |
| 1997 | 20 | 0 |
| 1998 | 29 | 0 |
| 1999 | 27 | 0 |
| 2000 | 29 | 0 |
| 2001 | 32 | 7 |
| 2002 | 31 | 36 |
| 2003 | 43 | 58 |
| 2004 | 38 | 50 |
| 2005 | 18 | 56 |
| 2006 | 55 | 34 |
| 2007 | 43 | 27 |
| 2008 | 38 | 45 |
| 2009 | 22 | 30 |
| 2010 | 32 | 64 |
| 2011 | 34 | 74 |
| 2012 | 57 | 69 |
| 2013 | 55 | 77 |
| 2014 | 77 | 87 |
| 2015 | 75 | 91 |
| 2016 | 75 | 82 |
| 2017 | 73 | 77 |
| 2018 | 88 | 81 |
| 2019 | 76 | 54 |
| 2020 | 82 | 63 |
| 2021 | 69 | 73 |
| 2022 | 62 | 50 |
| 2023 | 62 | 67 |
| 2024 | 87 | 92 |
| 2025 | 84 | 54 |
| 2026 | 48 | 38 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- E21B 33/043Specially adapted for underwater well heads541
- E21B 33/05Cementing-heads274
- E21B 33/047For plural tubing strings259
- E21B 33/0415Rotating or floating support for tubing or casing hanger166
- E21B 33/0422A suspended tubing or casing being gripped by a slip or an155
- E21B 33/0407With a suspended electrical cable141
Recent patents
- Hydraulic spider tubular centering systems and methods for use thereof22 Sep 2026US 12,742,359 B2Forum US, Inc.
- Selectively powering an electrical submersible pump assembly15 Sep 2026US 12,735,964 B2Saudi Arabian Oil Company
- Penetrator system for electrical submersible pumps8 Sep 2026US 12,729,596 B2Sonic Connectors Ltd.
- Conditioning a tubing head back pressure valve receptacle25 Aug 2026US 12,716,312 B2Saudi Arabian Oil Company
- Electrolytic pumping system25 Aug 2026US 12,716,332 B2
- Space-Out Mechanism for a Tubing Hanger and a Tree8 Oct 2026US 2026/0308996 A1Innovex International, Inc.
- Spring assist system with positional feedback for carriers of snubbing slip bowls1 Oct 2026US 2026/0298036 A1Consolidated Rig Works, L.P.
- Anti-extrusion device with integral plate and lattice for casing hanger annular seal24 Sep 2026US 2026/0286802 A1Baker Hughes Pressure Control LLC
- Orientation tools for tubing hangers17 Sep 2026US 2026/0275824 A1Onesubsea, LLC
- Liner hanger20 Aug 2026US 2026/0243152 A1China Petroleum & Chemical Corporation
Most cited
By later US patents
- Insulated and/or concentric coiled tubing429US 6,015,015 ABJ Services Company, U.S.A. · 2000
- Downhole surge pressure reduction system and method of use340US 5,960,881 AJerry P. Allamon · 1999
- Sealed electrical conductor method and arrangement for use with a well bore in hazardous areas332US 5,289,882 A1994
- Sealing system for a well bore in which a hot fluid is circulated280US 4,513,816 ASociete Nationale Elf Aquitaine (Production) · 1985
- Top drive casing system213US 6,536,520 B1Weatherford/Lamb, Inc. · 2003