- 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: 2837
10-year publication summary
|
180
|
143
|
142
|
185
|
219
|
156
|
138
|
146
|
127
|
24
|
| 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 | 2026 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Halliburton Energy Services, Inc. | 21169 |
518 |
| Schlumberger Technology Corporation | 11471 |
243 |
| Schlumberger Canada Limited | 7550 |
147 |
| Saudi Arabian Oil Company | 13943 |
138 |
| Services Petroliers Schlumberger | 5976 |
130 |
| Schlumberger Technology B.v. | 5270 |
119 |
| Weatherford Technology Holdings, LLC | 2068 |
94 |
| Baker Hughes Incorporated | 5045 |
62 |
| Prad Research and Development Limited | 2679 |
53 |
| Grant Prideco, Inc. | 427 |
48 |
| Schlumberger Holdings Limited | 2740 |
45 |
| National Oilwell Varco, L.P. | 1700 |
40 |
| Aramco Services Company | 4162 |
36 |
| Landmark Graphics Corporation | 1508 |
35 |
| Baker Hughes Oilfield Operations, LLC | 2436 |
35 |
| M-I L.L.C. | 772 |
27 |
| Nabors Drilling Technologies USA, Inc. | 571 |
27 |
| Enhanced Drilling AS | 43 |
23 |
| Chevron U.S.A. Inc. | 4073 |
19 |
| Pruitt Tool & Supply Co. | 73 |
19 |
| Other owners | 979 |