IPC Main Group
E21B 47/00 Survey of boreholes or wells
Introduced: September 1968
Last revised: January 2012
Classification Context
- Section:
- FIXED CONSTRUCTIONS
- Class:
- EARTH OR ROCK DRILLING; MINING
- Subclass:
- EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
Additional Content
Glossary
borehole boreholes an unlined shaft drilled into the ground, typically for the purposes of extracting water, crude oil or natural gas this is often referred to as the wellbore.
Limiting references
Monitoring pressure or flow of drilling fluid
Related Keywords
surveying BOREHOLESSURVEYING of boreholes
15 direct subcodes
Child Classifications
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- E21B 47/001 for underwater installations
- E21B 47/002 by visual inspection
- E21B 47/003 Determining well or borehole volumes
- E21B 47/005 Monitoring or checking of cementation quality or level
- E21B 47/007 Measuring stresses in a pipe string or casing
- E21B 47/008 Monitoring of down-hole pump systems, e.g. for the detection of "pumped-off" conditions
- E21B 47/01 Devices for supporting measuring instruments on drill bits, pipes, rods or wirelines; Protecting measuring instruments in boreholes against heat, shock, pressure or the like
- E21B 47/02 Determining slope or direction
- E21B 47/04 Measuring depth or liquid level
- E21B 47/06 Measuring temperature or pressure
- E21B 47/08 Measuring diameters or related dimensions at the borehole
- E21B 47/09 Locating or determining the position of objects in boreholes or wells; Identifying the free or blocked portions of pipes
- E21B 47/1 Locating fluid leaks, intrusions or movements
- E21B 47/12 Means for transmitting measuring-signals or control signals from the well to the surface, or from the surface to the well, e.g. for logging while drilling
- E21B 47/26 Storing data down-hole, e.g. in a memory or on a record carrier
Top Applicants
Top 10 applicants by patent filingsfor class E21, 2013–2023, worldwide · Source: EPO PATSTAT
- HALLIBURTON ENERGY SERVICES GROUP US 26,607
- PETROCHINA COMPANY 14,382
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 10,137
- CNPC (CHINA NATIONAL PETROLEUM CORPORATION) 6,517
- BAKER HUGHES US 6,269
- SCHLUMBERGER TECHNOLOGY US 5,929
- SAUDI ARABIAN OIL COMPANY SA 5,880
- SOUTHWEST PETROLEUM UNIVERSITY 4,477
- CHINA UNIVERSITY OF MINING AND TECHNOLOGY 4,357
- SCHLUMBERGER TECHNOLOGY NL 4,219