E21B21/14 - CPC Classification Index

#1

20250243397

2025-07-31

EFFICIENT SWELLING INHIBITOR FOR DRILLING FOAMS

#2

20250230721

2025-07-17

DRILL STRING AND COMPONENTS THEREFOR

#3

20250197713

2025-06-19

COMPOSITIONS FOR THE DISSOLUTION OF CALCIUM NAPHTHENATE AND METHODS OF USE

#4

20250172062

2025-05-29

COAL MINING SYSTEM AND METHOD OF DUAL CIRCULATION DRILLING WITH MECHANICAL REAMING AND ABRASIVE JET

#5

20240336832

2024-10-10

Propoxylates for foam enhancement

#6

20240166938

2024-05-23

Compositions for the dissolution of calcium naphthenate and methods of use

#7

20230249141

2023-08-10

Apparatus and method for making variable density foam fluid systems

#8

20220290518

2022-09-15

Repairing a cased wellbore

#9

20220243540

2022-08-04

Double-channel fluid injection apparatus

#10

20220111339

2022-04-14

Apparatus and method for making variable density foam fluid systems

#11

20200270504

2020-08-27

Pickering foam drilling fluids

#12

20190352985

2019-11-21

Method and apparatus for maintaining bottom hole pressure during connections

#13

20190330942

2019-10-31

Foam cap drilling methods

#14

20190100980

2019-04-04

Ball drop two stage valve

#15

20190055450

2019-02-21

Layered double hydroxides for oil-based drilling fluids

#16

20190003261

2019-01-03

DRILLING TOOL AND DRILLING METHOD

#17

20180274299

2018-09-27

Multi fluid drilling system

#18

20180252045

2018-09-06

Rotational drill bits and drilling apparatuses including the same

#19

20160281457

2016-09-29

Test packer and method for use

#20

20160230528

2016-08-11

Friction and wear reduction of downhole tubulars using graphene

#21

20160123087

2016-05-05

Rotational drill bits and drilling apparatuses including the same

#22

20160075932

2016-03-17

Foamed fluid compositions having high salinity using anionic surfactants and methods therefor

#23

20160068736

2016-03-10

REVERSIBLE FOAMED WELLBORE FLUIDS

#24

20160053542

2016-02-25

Apparatus and Method for Underbalanced Drilling and Completion of a Hydrocarbon Reservoir

#25

20150377002

2015-12-31

ENVIRONMENTALLY FRIENDLY BASE FLUIDS AND METHODS FOR MAKING AND USING SAME

#26

20150292279

2015-10-15

Method of Stopping Lost Circulation

#27

20150034302

2015-02-05

Casing filling tool

#28

20150013971

2015-01-15

Test packer and method for use

#29

20150000915

2015-01-01

Remediation of asphaltene-induced plugging of wellbores and production lines

#30

20140360733

2014-12-11

Controlled geyser well

#31

20140238665

2014-08-28

System, method and apparatus for manufacturing stable cement slurry for downhole injection

#32

20140231146

2014-08-21

METHOD OF ENHANCING DRILLING FLUID PERFORMANCE

#33

20140174723

2014-06-26

Defoaming agent compositions and methods of making and using same

#34

20140102699

2014-04-17

Defoaming agent compositions and methods of making and using same

#35

20130331301

2013-12-12

Methods for using complementary surfactant compositions

#36

20120175113

2012-07-12

Controlled hydrostatic pressure completion system

#37

20120175108

2012-07-12

Test packer and method for use

#38

20120118644

2012-05-17

Method and device for drilling shafts in ground layers consisting of rock, clay and/or related materials

#39

20120071367

2012-03-22

Environmentally friendly base fluids and methods for making and using same

#40

20120071366

2012-03-22

Complementary surfactant compositions and methods for making and using same

#41

20110284294

2011-11-24

Rotational drill bits and drilling apparatuses including the same

#42

20110224109

2011-09-15

Reversible Peptide Surfactants For Oilfield Applications

#43

20100258353

2010-10-14

Air/water separator and methods of use thereof

#44

20100147591

2010-06-17

Multiphase drilling systems and methods

#45

20100051283

2010-03-04

Subterranean methods of processing hydrocarbon fluid-containing deposits and hydrocarbon recovery arrangements for recovering hydrocarbon-containing fluid from hydrocarbon-containing deposits

#46

20100000795

2010-01-07

Enhanced oil-based foam drilling fluid compositions and method for making and using same

#47

20090325824

2009-12-31

Mixture for improved foaming in the extraction of petroleum or natural gas

#48

20090255732

2009-10-15

Method and apparatus for lateral well drilling with enhanced capability for clearing cuttings and other particles

#49

20090188721

2009-07-30

Membrane method of making drilling fluids containing microbubbles

#50

20090173543

2009-07-09

Slim-hole parasite string

#51

20090139771

2009-06-04

Method of making drilling fluids containing microbubbles

#52

20080121392

2008-05-29

Closed loop multiphase underbalanced drilling process

#53

20070199714

2007-08-30

CLOSED LOOP MULTIPHASE UNDERBALANCED DRILLING PROCESS

#54

20070187152

2007-08-16

Rock drill water separator

#55

20070144742

2007-06-28

Method of generating stable foam for oil and gas well cleanouts

#56

20060157282

2006-07-20

Managed pressure drilling

#57

20060124300

2006-06-15

Method for the circulation of gas when drilling or working a well

#58

20050269134

2005-12-08

Underbalanced drilling method and apparatus

#59

20050045336

2005-03-03

Propellant treatment and continuous foam removal of well debris

#60

20050045334

2005-03-03

Process of using a propellant treatment and continuous foam removal of well debris and apparatus therefore

#61

18508834

2024-06-25

Systems, processes, and modeling methods for drilling in hot dry rock using supercritical or dense phase carbon dioxide

#62

16700239

2020-10-27

Method for obtaining formation parameters of gas hydrate reservoir through well testing interpretation