E21B 47/04
Measuring depth or liquid level
E21B47/04 (Measuring depth or liquid level) appears on 878 US grants and 851 published applications in this corpus.
Search patents in E21B- Granted patents
- 878
- Published applications
- 851
- Assignees
- 324
- Inventors
- 1,755
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 10 | 0 |
| 1977 | 4 | 0 |
| 1978 | 1 | 0 |
| 1979 | 4 | 0 |
| 1980 | 3 | 0 |
| 1981 | 1 | 0 |
| 1982 | 10 | 0 |
| 1983 | 6 | 0 |
| 1984 | 8 | 0 |
| 1985 | 5 | 0 |
| 1986 | 6 | 0 |
| 1987 | 5 | 0 |
| 1988 | 9 | 0 |
| 1989 | 12 | 0 |
| 1990 | 10 | 0 |
| 1991 | 12 | 0 |
| 1992 | 10 | 0 |
| 1993 | 6 | 0 |
| 1994 | 8 | 0 |
| 1995 | 1 | 0 |
| 1996 | 4 | 0 |
| 1997 | 5 | 0 |
| 1998 | 10 | 0 |
| 1999 | 5 | 0 |
| 2000 | 11 | 0 |
| 2001 | 8 | 2 |
| 2002 | 17 | 17 |
| 2003 | 17 | 10 |
| 2004 | 6 | 6 |
| 2005 | 12 | 23 |
| 2006 | 14 | 12 |
| 2007 | 8 | 10 |
| 2008 | 10 | 21 |
| 2009 | 9 | 17 |
| 2010 | 15 | 21 |
| 2011 | 13 | 11 |
| 2012 | 17 | 23 |
| 2013 | 20 | 29 |
| 2014 | 23 | 29 |
| 2015 | 17 | 29 |
| 2016 | 20 | 47 |
| 2017 | 35 | 48 |
| 2018 | 26 | 46 |
| 2019 | 48 | 52 |
| 2020 | 41 | 56 |
| 2021 | 50 | 67 |
| 2022 | 61 | 68 |
| 2023 | 65 | 58 |
| 2024 | 67 | 71 |
| 2025 | 57 | 45 |
| 2026 | 36 | 33 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Geologic velocity modeling framework6 Oct 2026US 12,754,338 B2Schlumberger Technology Corporation
- Multifunctional fluorescent polymer-clay composite tracers22 Sep 2026US 12,742,381 B2Saudi Arabian Oil Company
- Method and system for controlling a multi-stage wireline operation in a well15 Sep 2026US 12,735,948 B2
- Calculating pull for a stuck drill string15 Sep 2026US 12,735,953 B2Landmark Graphics Corporation
- Measuring water level in highly deviated or horizontal hydrocarbon well sections15 Sep 2026US 12,735,978 B2Openfield
- Pump down well stimulation24 Sep 2026US 2026/0286814 A1Torsch Inc.
- Systems and methods for differentiating non-radioactive tracers downhole24 Sep 2026US 2026/0286839 A1Carbo Ceramics Inc.
- Systems and methods for multi-offset seismic profiling17 Sep 2026US 2026/0275859 A1Saudi Arabian Oil Company
- Well logging apparatus with buoyancy adjustment27 Aug 2026US 2026/0251058 A1Schlumberger Technology Corporation
- Well mastering20 Aug 2026US 2026/0243161 A1Schlumberger Technology Corporation
Most cited
By later US patents
- Method and apparatus for stimulation of multiple formation intervals249US 6,394,184 B2ExxonMobil Upstream Research Company · 2002
- Method of determining the location of a deep-well casing by magnetic field sensing190US 4,372,398 ACornell Research Foundation, Inc. · 1983
- Methods of servicing a well bore using self-activating downhole tool183US 7,322,416 B2Halliburton Energy Services.Inc. · 2008
- System for tracking and/or guiding an underground boring tool173US 6,035,951 ADigital Control Incorporated · 2000
- Composite coiled tubing apparatus and methods167US 5,828,003 ADowell, a division of Schlumberger Technology Corporation · 1998