- All sections
- E - Fixed constructions
- E21B - Earth or rock drillingobtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B 4/20 - Drives for drilling, used in the borehole combined with surface drive
Patent holdings for IPC class E21B 4/20
Total number of patents in this class: 31
10-year publication summary
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2
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3
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2
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0
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3
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2
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0
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1
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1
|
1
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| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Schlumberger Technology Corporation | 10898 |
5 |
| Halliburton Energy Services, Inc. | 20964 |
4 |
| Bauer Spezialtiefbau GmbH | 114 |
2 |
| Schlumberger Canada Limited | 7369 |
1 |
| Schlumberger Technology B.v. | 5184 |
1 |
| Weatherford Technology Holdings, LLC | 2028 |
1 |
| Smith International, Inc. | 717 |
1 |
| Bly IP Inc. | 31 |
1 |
| Cameron International Corporation | 1342 |
1 |
| China Railway Engineering Equipment Group Co., Ltd. | 46 |
1 |
| Extreme Machining Australia Pty Ltd | 6 |
1 |
| Longyear TM, Inc. | 100 |
1 |
| National Oilwell DHT, L.P. | 123 |
1 |
| National Oilwell Varco, L.P. | 1689 |
1 |
| Saudi Arabian Oil Company | 13409 |
1 |
| Services Petroliers Schlumberger | 5830 |
1 |
| Vermeer Manufacturing Company | 639 |
1 |
| Cameron Technologies Limited | 215 |
1 |
| Boart Longyear Company | 157 |
1 |
| BTD Bohrtechnik AG | 1 |
1 |
| Other owners | 3 |