Fishing for or freeing objects in boreholes or wells

Introduced: September 1968

Last revised: January 2006

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

Filing statistics

IPC E21B 31/00 belongs to the parent subclass E21B, which recorded 363,999 patent applications worldwide between 2013 and 2023. Annual filings grew from 30,128 in 2013 to 33,441 in 2023 (+11%), peaking at 39,369 applications in 2020. The most active applicants in class E21 are HALLIBURTON ENERGY SERVICES GROUP (26,607 applications), PETROCHINA COMPANY (14,382 applications) and SINOPEC (CHINA PETROCHEMICAL CORPORATION) (10,137 applications).

Source: EPO PATSTAT, worldwide filings

Related Keywords

freeing objects in BOREHOLESextractors for broken drillsFISHING -tools for boreholesSCOOP(S) as fishing tools in boreholes

5 direct subcodes

Child Classifications

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E21B 31/03 Freeing by flushing
E21B 31/06 using magnetic means
E21B 31/08 using junk baskets or the like
E21B 31/107 using impact means for releasing stuck parts, e.g. jars
E21B 31/12 Grappling tools, e.g. tongs or grabs

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