- 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 21/08 - Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure
Patent holdings for IPC class E21B 21/08
Total number of patents in this class: 2791
10-year publication summary
|
202
|
180
|
143
|
142
|
185
|
218
|
156
|
136
|
145
|
116
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Halliburton Energy Services, Inc. | 21021 |
514 |
| Schlumberger Technology Corporation | 11023 |
231 |
| Schlumberger Canada Limited | 7418 |
144 |
| Saudi Arabian Oil Company | 13622 |
137 |
| Services Petroliers Schlumberger | 5874 |
128 |
| Schlumberger Technology B.v. | 5217 |
117 |
| Weatherford Technology Holdings, LLC | 2034 |
91 |
| Baker Hughes Incorporated | 5179 |
64 |
| Prad Research and Development Limited | 2687 |
53 |
| Grant Prideco, Inc. | 396 |
47 |
| Schlumberger Holdings Limited | 2791 |
46 |
| National Oilwell Varco, L.P. | 1693 |
40 |
| Aramco Services Company | 4090 |
36 |
| Baker Hughes Oilfield Operations, LLC | 2380 |
34 |
| Landmark Graphics Corporation | 1517 |
33 |
| M-I L.L.C. | 806 |
27 |
| Nabors Drilling Technologies USA, Inc. | 562 |
27 |
| Enhanced Drilling AS | 44 |
23 |
| Baker Hughes, a GE Company, LLC | 2107 |
19 |
| Chevron U.S.A. Inc. | 4014 |
18 |
| Other owners | 962 |