E21B 47/20
By modulation of mud waves
Official title: by modulation of mud waves, e.g. by continuous modulation
E21B47/20 (By modulation of mud waves) appears on 209 US grants and 154 published applications in this corpus.
Search patents in E21B- Granted patents
- 209
- Published applications
- 154
- Assignees
- 83
- Inventors
- 356
- Latest grant
- 18 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 4 | 0 |
| 1977 | 1 | 0 |
| 1978 | 3 | 0 |
| 1979 | 4 | 0 |
| 1980 | 3 | 0 |
| 1981 | 3 | 0 |
| 1982 | 0 | 0 |
| 1983 | 0 | 0 |
| 1984 | 3 | 0 |
| 1985 | 3 | 0 |
| 1986 | 3 | 0 |
| 1987 | 5 | 0 |
| 1988 | 4 | 0 |
| 1989 | 3 | 0 |
| 1990 | 2 | 0 |
| 1991 | 1 | 0 |
| 1992 | 3 | 0 |
| 1993 | 5 | 0 |
| 1994 | 3 | 0 |
| 1995 | 0 | 0 |
| 1996 | 4 | 0 |
| 1997 | 2 | 0 |
| 1998 | 3 | 0 |
| 1999 | 2 | 0 |
| 2000 | 4 | 0 |
| 2001 | 6 | 1 |
| 2002 | 2 | 2 |
| 2003 | 1 | 2 |
| 2004 | 2 | 3 |
| 2005 | 3 | 5 |
| 2006 | 1 | 5 |
| 2007 | 4 | 3 |
| 2008 | 4 | 4 |
| 2009 | 2 | 3 |
| 2010 | 1 | 3 |
| 2011 | 3 | 2 |
| 2012 | 4 | 5 |
| 2013 | 2 | 7 |
| 2014 | 3 | 6 |
| 2015 | 5 | 11 |
| 2016 | 6 | 11 |
| 2017 | 14 | 16 |
| 2018 | 11 | 15 |
| 2019 | 19 | 10 |
| 2020 | 17 | 4 |
| 2021 | 2 | 3 |
| 2022 | 8 | 8 |
| 2023 | 6 | 9 |
| 2024 | 5 | 6 |
| 2025 | 5 | 6 |
| 2026 | 5 | 4 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Rotary pulser with regenerative control18 Aug 2026US 12,709,979 B2APS Tech LLC
- Method and system for fast pulse telemetry23 Jun 2026US 12,662,935 B2MS Directional, LLC
- Communication method for untethered downhole systems24 Mar 2026US 12,584,405 B2Schlumberger Technology Corporation
- Rotary pulser with regenerative control17 Mar 2026US 12,577,875 B2APS Tech LLC
- Axial sinusoidal pulser20 Jan 2026US 12,529,305 B1Schlumberger Technology Corporation
- Method and system for fast pulse telemetry with altered pulse coding8 Oct 2026US 2026/0309028 A1MS Directional, LLC
- Communication method for untethered downhole systems6 Aug 2026US 2026/0226827 A1Schlumberger Technology Corporation
- Systems and methods for communication with bottom-hole assemblies30 Jul 2026US 2026/0218608 A1
- Downhole measurements of borehole mud and cementing properties15 Jan 2026US 2026/0015935 A1Halliburton Energy Services.Inc.
- Rotary pulser with flow bypass elements25 Dec 2025US 2025/0389186 A1APS Technology, Inc.
Most cited
By later US patents
- Acoustic data link and formation property sensor for downhole MWD system315US 5,924,499 AHalliburton Energy Services.Inc. · 1999
- Method and apparatus for transmitting information to the surface from a drill string down hole in a well156US 6,714,138 B1APS Technology, Inc. · 2004
- Integrated modulator and turbine-generator for a measurement while drilling tool155US 5,517,464 ASchlumberger Technology Corporation · 1996
- Method and apparatus for communicating data in a wellbore and for detecting the influx of gas115US 5,592,438 ABaker Hughes Incorporated · 1997
- Method and apparatus for improved communication in a wellbore utilizing acoustic signals107US 5,995,449 ABaker Hughes Incorporated · 1999