PlainPatent

CPC technology class · E21

E21B - Earth Or Rock Drilling

Earth or rock drilling; obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells. 39,943 US utility patents granted 2015–2025, with the leading assignees and year-by-year grant trajectory.

39,943
US patents granted
#1/4
in E21
93.6%
E21 class share
+9%
5-yr velocity

The verdict

According to USPTO PatentsView, Earth Or Rock Drilling ranks #42 of 670 CPC technology areas - 39,943 US patents granted since 2015, with recorded grant volume up 9% over five years.

#42
of 670 CPC technology areas
39,943
US patents granted, 2015–2025
Halliburton Energy Services
leading assignee (6,516)
+9%
grant velocity, last 5 yrs

How E21B's grant cadence moved

Between 2020–2024, E21B recorded 18,958 grants versus 17,325 in 2015–2019 (+9% equal-window velocity). Across complete years, output peaked in 2019 at 4,523 grants and bottomed in 2015 at 2,754 (+64% peak-over-trough). Lead assignee Halliburton Energy Services, Inc. holds 16.3% of the class ; the top three share 32.1%.

Leaderboard read

E21B concentration, lead at 16.3%

Halliburton Energy Services, Inc. leads this historical grant record at 16.3% of E21B - us corporation assignees hold 71% of class grants (24,239 of 34,265). Figures describe granted US utility patents in this CPC subclass, not current investment or legal strength.

Leader's share
16.3%

6,516 of 39,943 grants

Top three share
32.1%

of the class's recorded grants

Lead over #2
3,272

more grants than Schlumberger Technology Corporation

Where E21B sits inside E21

Among 4 subclasses in E21 (Earth OR Rock DRILLING; Mining), E21B ranks #1 and holds 93.6% of the parent class's 42,682 recorded grants. Sibling chips below are the other subclasses in the same parent class, not the nationwide volume/lead-share peers further down.

E21C 1,136 E21D 962 E21F 641

Rising assignees active in E21B

Company-wide grant multiples (2022–2024 vs 2019–2021) among assignees with ≥5 patents in this subclass. Growth is company-wide; class patent counts are subclass-specific.

  1. #1 Exxon Mobil Technology and Engineering Company 298x 0 → 298 company-wide · 60 in E21B
  2. #2 Shell USA, Inc. 110x 0 → 110 company-wide · 12 in E21B
  3. #3 Totalenergies Onetech 65x 0 → 65 company-wide · 9 in E21B
  4. #4 ICE Thermal Harvesting, LLC 45x 1 → 45 company-wide · 33 in E21B
  5. #5 Locus Solutions Ipco, LLC 35x 0 → 35 company-wide · 11 in E21B

E21B grants by year, peak 2019 (4,523)

US utility-patent grants per year in E21B, 2015–2025 - recent five years are up 9% versus 2015–2019.

2,0002,5003,0003,5004,0004,5005,000 20152016201720182019202020212022202320242025 2,558

Who leads E21B?

The 12 most active assignees in Earth OR Rock DRILLING; Obtaining OIL, GAS, Water, Soluble OR Meltable Materials OR A Slurry OF Minerals From Wells - wider bars mean more grants

patents

What this shows Halliburton Energy… is the most active filer in E21B, holding 6,516 of the 39,943 patents in this class. Concentration at the top signals how contestable this technology area is for new entrants.

Source USPTO PatentsView, granted utility patents As of 2015–2025 grant years
View data table
Top patent holders in CPC subclass E21B
Rank Company Patents in E21B
#1 Halliburton Energy Services, Inc. 6,516
#2 Schlumberger Technology Corporation 3,244
#3 Saudi Arabian OIL Company 3,064
#4 Baker Hughes Holdings LLC 1,273
#5 Baker Hughes, a GE company, LLC 1,107
#6 Weatherford Technology Holdings, LLC 829
#7 Baker Hughes Oilfield Operations LLC 598
#8 Cameron International Corporation 514
#9 Chevron U.S.A. Inc. 400
#10 Exxonmobil Upstream Research Company 350
#11 Landmark Graphics Corporation 319
#12 ConocoPhillips Company 299
#13 National Oilwell Varco, L.P. 298
#14 US Synthetic Corporation 234
#15 Smith International, Inc. 223
#16 Nabors Drilling Technologies USA, Inc. 197
#17 Southwest Petroleum University 177
#18 OneSubsea IP UK Limited 176
#19 King Fahd University OF Petroleum AND Minerals 175
#20 Shell OIL Compny 170

Footprint here vs. claim strategy

Each dot is a leading E21B assignee, placed by how many patents it holds in this class (horizontal) against its company-wide average claims per patent (vertical) - a read on whether the class is led by broad-but-shallow filers or focused deep-claim players.

Top 14 E21B assignees by class footprint. Bubble size = patents in E21B. Source: USPTO PatentsView (claim depth is company-wide across all classes). Scatter plot of 14 data points (bubble-sized by third dimension). 1416182022 -200002000400060008000 Patents in E21B Avg claims / patent (company-wide) Halliburton Energy…Schlumberger…Saudi Arabian OilBaker Hughes HoldingsBaker Hughes a GeWeatherford Technology…Baker Hughes Oilfield…Cameron InternationalChevron UExxonmobil Upstream…Landmark GraphicsConocophillipsNational Oilwell VarcoUs Synthetic
Top 14 E21B assignees by class footprint. Bubble size = patents in E21B. Source: USPTO PatentsView (claim depth is company-wide across all classes).

Classes near E21B's 39,943-grant footprint

Nationwide nearest neighbors for E21B (#42 of 670 by volume ; lead share 16.3%) - not the E21 parent-class siblings above.

Nearest by grant volume

B60W 39,530 B32B 39,314 G05D 37,264 G16H 42,899

Nearest by lead-assignee share

A24B 16.3% F25C 16.4% E03D 16.2% A01B 16.1%

Questions about E21B

Which company holds the most patents in E21B?
Halliburton Energy Services, Inc. leads E21B with 6,516 patents (16.3% of the subclass). By PatentsView assignee type, us corporations account for 71% of class grants.
Which E21B assignees grew fastest recently?
Among assignees with ≥5 grants in E21B, Exxon Mobil Technology and Engineering Company shows the highest company-wide grant multiple (298x: 0 grants in 2019–2021 → 298 in 2022–2024) while holding 60 patents in this subclass. Growth is company-wide, not class-only.
How does E21B compare inside parent class E21?
Inside E21 (Earth OR Rock DRILLING; Mining), E21B ranks #1 of 4 subclasses by grant volume and holds 93.6% of the parent class total. The largest sibling is E21C (1,136 grants).

What to do with this data

E21B in context - here's where to go next.

  • Halliburton Energy Services, Inc. leads E21B with 6,516 grants in this class. See full portfolio
  • E21B ranks #42 of 670 by grant volume among all tracked CPC technology areas. See the ranking
  • Inside parent class E21, the largest sibling subclass is E21C with 1,136 grants. Explore E21C

Figures reflect USPTO PatentsView grant data through 2026-05-15; pending applications not yet granted are not counted.

Methodology - E21B figures are USPTO PatentsView granted-utility totals for this subclass (39,943 grants in the tracked window).

Every figure on PlainPatent is rendered directly from USPTO source data, no number is typed in by an editor. This page draws directly on USPTO source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.