E21B 49/00
Testing the nature of borehole walls
Official title: Testing the nature of borehole walls; Formation testing; Methods or apparatus for obtaining samples of soil or well fluids, specially adapted to earth drilling or wells
E21B49/00 (Testing the nature of borehole walls) appears on 7,385 US grants and 7,432 published applications in this corpus.
Search patents in E21B- Granted patents
- 7,385
- Published applications
- 7,432
- Assignees
- 1,434
- Inventors
- 12,357
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 37 | 0 |
| 1977 | 30 | 0 |
| 1978 | 25 | 0 |
| 1979 | 18 | 0 |
| 1980 | 25 | 0 |
| 1981 | 55 | 0 |
| 1982 | 44 | 0 |
| 1983 | 43 | 0 |
| 1984 | 59 | 0 |
| 1985 | 60 | 0 |
| 1986 | 53 | 0 |
| 1987 | 66 | 0 |
| 1988 | 61 | 0 |
| 1989 | 73 | 0 |
| 1990 | 50 | 0 |
| 1991 | 52 | 0 |
| 1992 | 67 | 0 |
| 1993 | 57 | 0 |
| 1994 | 70 | 0 |
| 1995 | 48 | 0 |
| 1996 | 48 | 0 |
| 1997 | 47 | 0 |
| 1998 | 55 | 0 |
| 1999 | 65 | 0 |
| 2000 | 69 | 0 |
| 2001 | 69 | 10 |
| 2002 | 69 | 68 |
| 2003 | 56 | 74 |
| 2004 | 69 | 129 |
| 2005 | 65 | 100 |
| 2006 | 88 | 88 |
| 2007 | 99 | 97 |
| 2008 | 70 | 118 |
| 2009 | 69 | 177 |
| 2010 | 109 | 178 |
| 2011 | 101 | 180 |
| 2012 | 141 | 193 |
| 2013 | 159 | 256 |
| 2014 | 179 | 307 |
| 2015 | 197 | 407 |
| 2016 | 256 | 467 |
| 2017 | 320 | 549 |
| 2018 | 348 | 498 |
| 2019 | 552 | 496 |
| 2020 | 537 | 502 |
| 2021 | 500 | 566 |
| 2022 | 510 | 461 |
| 2023 | 510 | 437 |
| 2024 | 420 | 430 |
| 2025 | 343 | 403 |
| 2026 | 272 | 241 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
- E21B 49/08Obtaining fluid samples or testing fluids, in boreholes or wells3,295
- E21B 49/02Testing the nature of borehole walls: by mechanically taking samples of the680
- E21B 49/005Testing the nature of borehole walls or the formation by using drilling666
- E21B 49/008Testing the nature of borehole walls: by injection test634
- E21B 49/003Testing the nature of borehole walls: by analysing drilling variables or conditions535
- E21B 49/006Measuring wall stresses in the borehole413
- E21B 49/001Testing the nature of borehole walls: specially adapted for underwater installations108
Recent patents
- Subsurface detection system and method6 Oct 2026US 12,753,692 B2Schlumberger Technology Corporation
- Methods to perform joint inversion of formation data and joint inversion systems6 Oct 2026US 12,754,340 B2Halliburton Energy Services.Inc.
- Systems and methods for determining reactivity indices for carbon dioxide sequestration29 Sep 2026US 12,747,651 B2Schlumberger Technology Corporation
- Logging tool inversion integration29 Sep 2026US 12,747,661 B2Schlumberger Technology Corporation
- Coring tools having coring shafts with associated internal static sleeves29 Sep 2026US 12,747,664 B2Schlumberger Technology Corporation
- Mechanical energy assisted hydraulic fracturing8 Oct 2026US 2026/0309015 A1
- Downhole sensing based on time domain reflectometry using resistance and capacitance coupling8 Oct 2026US 2026/0309026 A1Halliburton Energy Services.Inc.
- Method for measuring downhole holdup, and method for determining downhole fluid interface and geometric distribution8 Oct 2026US 2026/0309606 A1China University of Petroleum (East China)
- Fluid cell device and method for measuring drilling mud properties8 Oct 2026US 2026/0309674 A1
- Low-frequency strain data recorded with distributed acoustic sensing (das) for hydraulic fracturing monitoring8 Oct 2026US 2026/0309887 A1Schlumberger Technology Corporation
Most cited
By later US patents
- Controlling hydrocarbon production609US 10,677,035 B2Saudi Arabian Oil Company · 2020
- In-situ tuned microwave oil extraction process483US 5,082,054 A1992
- System for recovery of petroleum from petroleum impregnated media433US 4,817,711 A1989
- Method and apparatus for testing, completion and/or maintaining wellbores using a sensor device420US 5,829,520 ABaker Hughes Incorporated · 1998
- Drilling systems with sensors for determining properties of drilling fluid downhole402US 6,176,323 B1Baker Hughes Incorporated · 2001