E21B 7/14
Drilling by use of heat
Official title: Drilling by use of heat, e.g. flame drilling
E21B7/14 (Drilling by use of heat) appears on 376 US grants and 387 published applications in this corpus.
Search patents in E21B- Granted patents
- 376
- Published applications
- 387
- Assignees
- 134
- Inventors
- 542
- Latest grant
- 15 Sep 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 5 | 0 |
| 1977 | 3 | 0 |
| 1978 | 10 | 0 |
| 1979 | 2 | 0 |
| 1980 | 4 | 0 |
| 1981 | 4 | 0 |
| 1982 | 1 | 0 |
| 1983 | 3 | 0 |
| 1984 | 4 | 0 |
| 1985 | 1 | 0 |
| 1986 | 2 | 0 |
| 1987 | 3 | 0 |
| 1988 | 3 | 0 |
| 1989 | 1 | 0 |
| 1990 | 2 | 0 |
| 1991 | 4 | 0 |
| 1992 | 7 | 0 |
| 1993 | 1 | 0 |
| 1994 | 0 | 0 |
| 1995 | 1 | 0 |
| 1996 | 3 | 0 |
| 1997 | 1 | 0 |
| 1998 | 3 | 0 |
| 1999 | 4 | 0 |
| 2000 | 1 | 0 |
| 2001 | 0 | 0 |
| 2002 | 0 | 0 |
| 2003 | 1 | 4 |
| 2004 | 2 | 4 |
| 2005 | 2 | 3 |
| 2006 | 3 | 10 |
| 2007 | 1 | 5 |
| 2008 | 4 | 6 |
| 2009 | 5 | 5 |
| 2010 | 4 | 16 |
| 2011 | 6 | 10 |
| 2012 | 5 | 15 |
| 2013 | 8 | 16 |
| 2014 | 11 | 20 |
| 2015 | 18 | 16 |
| 2016 | 12 | 18 |
| 2017 | 13 | 19 |
| 2018 | 16 | 21 |
| 2019 | 21 | 22 |
| 2020 | 21 | 26 |
| 2021 | 27 | 33 |
| 2022 | 31 | 31 |
| 2023 | 34 | 30 |
| 2024 | 25 | 15 |
| 2025 | 20 | 26 |
| 2026 | 13 | 16 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Millimeter-wave directed-energy excavation15 Sep 2026US 12,735,985 B2Massachusetts Institute of Technology
- High power laser tunneling mining and construction equipment and methods of use25 Aug 2026US 12,715,063 B2Foro Energy, Inc.
- Composite umbilical for pulse power boring system25 Aug 2026US 12,716,297 B2Halliburton Energy Services.Inc.
- Mass flow for non-contact boring18 Aug 2026US 12,709,944 B2Phoenix Boring, Inc.
- High temperature superconducting cable based power delivery system in pulsed power drilling11 Aug 2026US 12,704,024 B2Halliburton Energy Services.Inc.
- High voltage electro pulse rock drilling8 Oct 2026US 2026/0308983 A1Epiroc Rock Drills Aktiebolag
- A pulsed power drilling system and method for breaking a mineral substrate by use of microwave radiation for ionizing a fluid volume8 Oct 2026US 2026/0308984 A1Epiroc Rock Drills Aktiebolag
- Methods and Systems for Non-Contact Boring of Tunnels, Shafts, and Trenches17 Sep 2026US 2026/0275812 A1Phoenix Boring, Inc.
- Cleaning boreholes formed by millimeter wave drilling27 Aug 2026US 2026/0251017 A1Quaise Energy, Inc.
- Method for synergistic permeability enhancement and extraction of coal mine gas23 Jul 2026US 2026/0210224 A1Chongqing University
Most cited
By later US patents
- Method and apparatus for conversion of coal in situ366US 4,776,638 AUniversity of Kentucky Research Foundation · 1988
- Focused shock spark discharge drill using multiple electrodes183US 4,741,405 ATetra Corporation · 1988
- Portable electrohydraulic mining drill168US 5,896,938 ATetra Corporation · 1999
- Well perforating apparatus and method108US 4,227,582 A1980
- Continuous drilling of vertical boreholes by thermal processes: including rock spallation and fusion103US 5,771,984 AMassachusetts Institute of Technology · 1998