E21B 47/047
Liquid level
Official title: Liquid level (measuring depth or liquid level using radioactive markers E21B47/053)
E21B47/047 (Liquid level) appears on 270 US grants and 230 published applications in this corpus.
Search patents in E21B- Granted patents
- 270
- Published applications
- 230
- Assignees
- 136
- Inventors
- 506
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 0 | 0 |
| 1978 | 0 | 0 |
| 1979 | 2 | 0 |
| 1980 | 1 | 0 |
| 1981 | 1 | 0 |
| 1982 | 2 | 0 |
| 1983 | 3 | 0 |
| 1984 | 1 | 0 |
| 1985 | 2 | 0 |
| 1986 | 3 | 0 |
| 1987 | 1 | 0 |
| 1988 | 3 | 0 |
| 1989 | 3 | 0 |
| 1990 | 5 | 0 |
| 1991 | 6 | 0 |
| 1992 | 5 | 0 |
| 1993 | 4 | 0 |
| 1994 | 3 | 0 |
| 1995 | 0 | 0 |
| 1996 | 1 | 0 |
| 1997 | 3 | 0 |
| 1998 | 7 | 0 |
| 1999 | 2 | 0 |
| 2000 | 4 | 0 |
| 2001 | 4 | 0 |
| 2002 | 6 | 4 |
| 2003 | 8 | 5 |
| 2004 | 2 | 2 |
| 2005 | 0 | 2 |
| 2006 | 2 | 4 |
| 2007 | 3 | 1 |
| 2008 | 2 | 7 |
| 2009 | 1 | 0 |
| 2010 | 5 | 9 |
| 2011 | 2 | 6 |
| 2012 | 8 | 8 |
| 2013 | 7 | 8 |
| 2014 | 8 | 10 |
| 2015 | 10 | 9 |
| 2016 | 3 | 10 |
| 2017 | 7 | 13 |
| 2018 | 9 | 13 |
| 2019 | 10 | 14 |
| 2020 | 16 | 17 |
| 2021 | 17 | 17 |
| 2022 | 12 | 22 |
| 2023 | 19 | 15 |
| 2024 | 20 | 22 |
| 2025 | 17 | 8 |
| 2026 | 6 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Measuring water level in highly deviated or horizontal hydrocarbon well sections15 Sep 2026US 12,735,978 B2Openfield
- Systems and methods for determining water depth and explosive depth in blastholes7 Jul 2026US 12,674,386 B2Dyno Nobel Asia Pacific Pty Limited
- Floatless pumps and control systems21 Apr 2026US 12,607,105 B2Nextech Environmental, LLC
- Methods for determining positions of fluid interfaces and detecting cement setting in a subterranean wellbore24 Mar 2026US 12,584,374 B2Schlumberger Technology Corporation
- Blowout preventer system with data playback27 Jan 2026US 12,535,942 B2Hydril USA Distribution LLC
- Methods for Determining Positions of Fluid Interfaces and Detecting Cement Setting in a Subterranean Wellbore30 Jul 2026US 2026/0218585 A1Schlumberger Technology Corporation
- Rcd seal and bearing condition22 Jan 2026US 2026/0022633 A1Weatherford Technology Holdings, LLC
- Systems and methods for inferring reservoir pressure based on initial coiled tubing run conditions15 Jan 2026US 2026/0015937 A1Schlumberger Technology Corporation
- Optimized method of sampling the zones1 Jan 2026US 2026/0002441 A1Landmark Graphics Corporation
- Method to mitigate wellbore instabilities18 Dec 2025US 2025/0382854 A1Schlumberger Technology Corporation
Most cited
By later US patents
- System and method for surface steerable drilling115US 8,210,283 B1Hunt Energy Enterprises, L.L.C. · 2012
- Downhole monitoring method and device78US 6,098,020 AShell Oil Company · 2000
- Artificial lift apparatus with automated monitoring characteristics76US 6,536,522 B2Weatherford/Lamb, Inc. · 2003
- Liquid level detection for artificial lift system control72US 5,634,522 A1997
- Liquid-level detector70US 4,989,452 ASolinst Canada Limited · 1991