Drilling Bits Design and Types - Presentation

Drilling Bits Design and Types - Presentation

1. DRILLING BITS
DRILLSTRING

2. Concept
CUTTINGTOOLPLACEDONTHEBOTTOMOFTHE
DRILLSTRINGTOCUTROCKSBYAPPLIENG
WEIGHTANDROATATION.
BITCLASSIFICATIIONIS:
lTRICORNEBITS.
lFIXEDCUTTERSBITS.
lSPECIALBITS.

3. OBJECTIVES
•PARTS IDENTIFICATION.
•DESIGN FEATURES.
•NOMENCLATURE.
•CUTTING MECHANICS
•FORMATIONS.
•APPLIED HYDRAULICS

4. OBJECTIVES
•DRILLABILITY INDEX.
•PERFORMANCE EVALUATION.
•WEAR & TEAR.
•OPERATONAL PROCEDURES.
•BICENTRIC.

6. Parts Identification
TRICON BITS
¡A.-PIN
¡B.-LEG
¡C.-CONE
¡D.-GAUGE
¡E.-COMPENSATOR
¡F.-BEARING
¡G.-NOZZLE
¡H.-SEAL
E A
B
GH
C
F
F
D

7. Parts Identification
FIXED CUTTERS
BITS
¡A.-PIN.
¡B.-MAKE UP SLOT.
¡C.-GAUGE
¡D.-DISPLACEMENT
PATH
¡F.-NOSE
¡G.-TAPER
¡H.-CONE
G
A
B
CD
E
FH

8. DESIGN FEATURES
¡CUTTING STRUCTURE.
¡BEARING SYSTEM.
¡SEALS.
¡CONES.

27. Bearing
System

28. BEARING SYSTEM

29. BEARING SYSTEM

47. CONE RETENTION COMPARISONS
• Ball Bearing Retention
–Concentrated Point Loads
–Cyclic Point Loading Causes Spalling
• Threaded Ring Retention
–Surface Contact
–No Spalling
–Reduces Lost Cone Rate by Two-Thirds
–Optional Cutter Materials

48. Bearing Life is Difficult to Predict
Primary Reason :
Variable Downhole Conditions
Customers Expect
Confident Prediction of Bearing Life
Bearing Failure Depends on Events

50. BEARING LIFE ESTIMATION PROCESS
Gather Baseline Data
Lithology
Bit Records
Dull Bits / Photos
Operation Reports
Drill Function Recordings
Daily
Directional
Mud
Personal Observations
Bearing Life Estimation Process
Identify and Cull Outliers
Quantify Competitive Performance
Measurement Method
Numeric Target
Demonstrate Expectations

51. SEAL
MINIMUM TOLERANCES OF SELFLUBRIOCATED BEARING
ALLOWES USE OF INCLINED SEAL FACES WHICH ALLOW
MAX BEARING LOADING.
ALSO USE NONROTATORY SEAL THAT AVOIDS THE
JAMMING.
SEALED BEARING GARANTEES EFFECTIVE BEARING
LUBRICATION AND BETTER BARRIER PERFORMANE.

54. SEAL

55. CONES
¡CONE OFFSET DEPENDS
ON BIT TYPES,
INTERFERENCE DESIGN
, FORMATION
¡ITS VALUE IS
DICTATED
FORMATION TYPE.

58. CUTTING STRUCTURE
MADEONCONESMOUNTEDONBITLEGSTHATARE
INTEGRALPARTSOFTHEBIT.
RADIALLOADSARETAKENBYTHEMAJOR
EXTERNALELEMENTWHICHARETHEBERAINGS.
THEREARETHREEMAINDESIGS:
•BEARINGS STANDARD WITH ROLLERS AND SMALL
BULLETS.
•SELFLUBRICATION BEARINGS WITH ROLLERS AND
SMALL BULLETS.
•SELGLUBRICATED FRICITON BEARINGS

59. CONES
¡PINION ANGLE
DEPENDS ON CONE
DIAMETER, FORMATION
, AND TYPE AND
DIAMETER OF THE BIT.
Angulodepiñon
journalenbarrena
deformacióndura
Piñon de balero
journal

60. CUTTING MECHANICS
PDC
(SHEAR)

61. CUTTING MECHANICS
INSERT/TOOTH
(SHREAD)

62. CUTTING MECHANICS
NATURAL DAIMOND
(SWEEP/INDENTATION)

63. CUTTING MECHANICS
TSP
(SHEAR/SWEEP)

69. CUTTING STRUCTURE
•CHISEL FORM
•HARDFACING

74. SINCETHECONESAREFORCEDTOROTATE
AROUNDTHECENTERTHEYSLIPASTHEY
ROTATEPRODUCINGSCRAPIN&ROLLING
(DRILLING).
CUTTING STRUCTURE

85. CUTTING STRUCTURE
¡FIXED CUTTERS BITS THEY ARE
COMPACT BODIES WITHOUT MOVING
PARTS; CUTTERS CAN BE:
¡NATURAL DIAMOND: LIMITED USE IN
VERY HARD AND ABRASIVE SPECIAL
CASES.
¡THERMALLY STABLE BITS (TSP): USED
TO DRILL HARD ROCKS (LIMESTONE,
BASALT, HARD FINE SANDS).

86. CUTTING STRUCTURE
¡POLICRYSTALI DIAMOND COMPACT BITS(PDC):
¡CUTTERS ( SENTHETIC DIAMOND-COMPACT
OF DIAMOND) ATTACHED TO BIT BODY
¡ITS HIDRAULICO DESIGN IS MADE WITH
SYSTEM OF NOZZLERAULIC DESIGN IS MADE
SOMILLAR TO THE TRICONE BITS

89. CUTTING STRUCTURE
SPECIALBITS.-
CANBE:
HOLE OPNNERS OR BICENTRIC, EMPLOYED
TI INCRESE AN ALREADY DRILLED
SMALLER HOLE DIAMETER.

90. CUTTING STRUCTURE
¡CUTTER DESIGN
¡HEIGHER ABRASION RESISTANCE.
¡HEIGHER IMPACT RESISTANCE.
¡ROCK VOLUME.
FIXED CUTTERS (PDC, TSP)
RADX
AXSYM
DIAX

91. CUTTING STRUCTURE WEAR
1. Inner cut structure
(all inner rows)
fixed cutters bits use 2/3 of bit radius.
2. -Outer cut structure
(Only gauge row.)
In columns 1 and 2 uses linear scale from the 0 to 8 to describe
cutter conditions:
Steel Teeth
middle tooth wearing down thru loss of height.
0 –No lost, wears / broken inserted.
fixed Cutters bits
wears and/or broken cutters.
0 –No loss, wears and/or broken cutters.
8 –total loss, wear and / or broken cutters.

92. IADC ROLLER BIT CLASSIFICATION

93. 93
IADC CLASSIFICATION –TRICON BIT
8-1/2” EHP 51
5 17 G
Soft Formations with
Low Compressive
Strength and High
Drillability
1
Medium to Medium Hard
Formations with High
Compressive Strength
2
Hard Semi-Abrasive
and Abrasive
Formations
3
Soft Formations with
Low Compressive
Strength and High
Drillability
4
Soft to Medium
Formations with Low
Compressive Strength
5
Medium Hard
Formations with High
Compressive Strength
6
Hard Semi-Abrasive
and Abrasive
Formations
7
Extremely Hard and
Abrasive Formations8
INSERT
BITS
STEEL
TOOTH
BITS
SERIES & CUTTING STRUCTURECUTTING
STRUCTURE
TYPE (1 TO 4)
1 ; SOFTEST
FORMATION IN A
SERIES
4 HARDEST
FRORMATION IN
SAME SERIES
BEARIN
DESCRIPTION
Standard
Roller
Bearing
1
Roller
Bearing Air
Cooled
2
Roller
Bearing
Gauge
Protec ted
3
Sealed
Roller
Bearing
4
Sealed
Roller Brg -
Gauge
Protec ted
5
Sealed
Friction
Bearing
6
Sealed
Frction Brg
Gauge
Protec ted
7
AVIALBLE
FEATURES
(OPTIONAL)
A - Air Application
B - Special Bearing Seal
C - Center Jet
D - Deviation Control
E - Extended Nozzles
G - Gauge/Body
Protection
H - Horizontal Steering
Appl.
J - Jet Deflection
L - Lug Pads
M - Motor Application
S - Standard Steel Tooth
T - Two Cone Bit
W - Enhanced Cutting
Structure
X - Predominantly Chisel
Tooth Insert
Y - Conical Tooth Insert
Z - Other Shape Insert

94. TOOTH
SOFT
HARD8
7
6
4
5
INSERT
2
1
3
8-3
4-1

95. IADC ROLLER BIT CLASSIFICATION

99. SOFT
HARD
1
8
7
6
4
5
TOOTH
INSERT
2
1
3
PDC

100. SOFT
HARD8
7
6
4
5
TOOTH
INSERT
DIAMONDD
2
1
3
PDC

101. SOFT
HARD8
7
6
4
5
TOOTH
INSERT
1
2
1
3
IMPREGNATED
DIAMOND
DIAMOND
PDC

105. CUTTING STRUCTURE WEAR
INNER AREA
2/3 RADIUS
CUTTING AREA
1/3 RADIUSTRICONE ZONNING
N-NOSE ROW
CONE #
M-MIDDLE ROW
1
G-GAUGE ROW2
A-ALL ROWS
3
FIXED CUTTER BITS
C-CONE
H-NOSE
T-TAPER
S-SHOULDER
G-GAUGE
H-ALL AREAS

106. BARING & GAUGE WEAR
SEALS, BEARING & STANDARD BEARING:
USE A LINEAR SCALE TO ESTIMATE BEARING LIFE.
0-NO WEAR.
8-WEAR, COMPLETELY WORN OUT.
SEALED BEARING:
E-SEAL EFFECTIVE
F-FAILED SEAL.
N-CAN NOT BE DETERMINED.
X-PDC/TSP BITS
GAUGE: MEASURE IN 1/16”:
1-IN GAUGE
1-1/16” LOSS OF GAUGE
2-2/16” LOSS OF GAUGE
A-4/16” LOSS OF GAUGE

107. REASONES TO POH BIT
BHA: BIT CHANGE, END OF DRILLING
DMF: DHM FAILURE.
DSF : DRILLSTRING FAILURE.
DST : DRILL STEM TEST.
DP : PLUGGED.CM: MUD CONDITIONS.
CP : CORE POINT.
FM : FORMATION CHANGE.
HP : HOLE PROBLEMS.
LOG : LOGGING.
PP : PUMP PRESSURE.
PR : ROP.
RIG : RIG REPAIRE.
TD : TOTAL DEPTH.
TQ : TORQUE.
WC : WEATHER.

108. COMMON BIT SIZES

109. TOLERANCE FO NEW BITS

113. IF WE UNDERSTAND THE APPLICATION WE CAN APPLY THE
DESIGN FEATURES NECESSARY TO ADDRESS THAT APPLICATION.

118. IADC 1992 WEAR EVALAUTION
Exter
CUTTING STRUCTURE
InterWEAR CARACT.Des.ZONE
BEARING /
SEALSGAUGE
OTHER
WEAR
CARACT.
REASON
POH
12345678
1 INTERNAL CODE STRUCTURE(ALL INTERNAL ROWS)
2 EXTERNAL CUTTING STRUCTURE(GAUGE ROWS ONLY)
3 WEAR FEATYRES (Use CODES OF CODE STRUCTURE)
4 LOCATION (WHERE WEAR FEATURES OCCURE)
5 BEARINGs /SAELS (CONES CONDITIONS)
6 GAUGE (FIANL GAUGE DIAMETER)
7 OTHE WEAR FEATURES ( NOT LIMITED TO CUTTING STRUCTURE)
8 REASON TO POH (WHY FINISH BIT RUN)
8 CODES

119. CUTTING STRUCTRE
InterExterWEAR CHAREC..Localiz.
BEARING /
SEALSGAUGE
OTHER
WEAR
CHARAC.
REASON
POH
12345678
3 WEAR FEATURE (USES ONLY CUTTING STRUCTURE CODE)
* SHOW CONE NUMBER AND LOCATION (4)
*BC –BROKEN CON
BF –BEARING FAILURE
BT –BROKEN TOOTH/CUTTER
BU -BOLD UP BIT
*CC –CRACKED CONE
*CD –CEASED CONE
CI -CONS INTERFERENCE
CR -CROWN
CT –CHIPPED TOOTH/CUTTER
ER -EROSSION
FC –PALIN WEAR
HC –HEAT CRACK
JD –JUNK DAMAGE
*LC –LOST CONE
LN –LOST NOZZLE
LT –LOST TOOTH/CUTTER
Perdidos
OC –ECCENTRIC WEAR
PB ------BIT (Contraída)
PN –PLLUGGED NOZZLE
NO –NON FEATURE WEAR
NR –DO NOT RE-RUN
RG –ROUNDED GAUGE
RR –RE-RUN
RO –“O” ROGo
SD –SKIRT DAMAGE
SS –SELF SHARPENING WEAR
TR -TREAD
WO –WASHE OUT
WT –WORN TOOTH/CUTTER

120. IADC CODE
¡TRICONE BIT
¡A-B-C-S
¡A.-CUTTING STRUCTURE(1-8).
¡B.-CUTTING STRUCTURE TYPE ( 1-4).
¡C.-BEARING/GAUGE ( 1-7).
¡S.-SPECIAL FEATURES (16)

121. IADC CODE
¡FIXED CUTTERS BITS
¡A-B-C-P
¡A.-BODY MATERIAL.
¡B.-CUTTER DENSITY.
¡C.-CUTTER SIZE/TYPE.
¡P.-PROFILE.

122. TSP BIT
TIPO S-248

123. HYBRID BIT

124. PORFILES
FISHTAIL
SHORTMEDIUMLONG

125. GEOLOGICAL PROCESSES & ROCKS
MAGMATICS ROCKS
MATURATIONN-EROSSION-TRANSPORT:
SEDIMENTES
SEDIMENTARY ROCKS
METAMORPHISM
PROCESS
COMPACTION
DIAGENESIS
PROCESS
METAMORPHIC ROCK

126. FORMATIONES
CLASTICSEDIMENTARYROCKS:FORMEDOFFRANGMENTSOF
CLASTICROCKS(PARTICULESOFMINERALSOROTHERROCKS
THEPRE-EXISTEDTHEM.
CHEMICALSEDIMENTARYROCKS:FORMEDBYPREICPITATION,
EVAPORATION,CHEMICALREACTIONSOFSALINESOLUTIONS.
ORGANICSEDIMETARYROCKS:FORMEDFROMRESTSOF
ORGANICMATERERS(PLANTSANDANIMALS).
SEDIMENTARY ROCKS
CLASTICCHEIMICALORGANIC
CONGLOMERATESCALCITESBITUMINE
SANDSTONEDOLOMITESCARBON
LIMONITESSANDSDISTADITES
ESQUISTOSGYPSUMLIMESSTONES
SALT/ANHIDRITE

127. FORMATIONES
THEYPOSSE:
•POROSITY:INTERGRANULARVOIDSPACEINAROCK.
•PERMEABILITY:ROCKFLUIDCONDUCTIVITY
.

128. FORMATIONES
HYDROCARBONEACCUMMULATION
POROUSROCKSTHATSTOREFLUIDSSUCHASSANDSTONE
ANDLIMESTONE.
RESEROVIRS
TRAPSWHEREFLUIDSAREACCUMMULATED.THEYCANBE
DEVHYDROCARBONEEXTRACTION.
THEYARECLASSIFIEDBY:
-TYPEOFENERGY.
-TYPEOFROCK.
-TYPEOFFLUID.

129. FORMATIONES
a)IGNEOUSROCKS.-COOLINGOFEARTHFUSEDMATTER
b)Rocassedimentarias.-DISINTEGRATIONOFIGNEOUS
ROCKSDUETOWEATHERFACTORSANDTRANSPORT
OFFRAGMENTSCREATEDSEDEMENTARYROCKS
SEDIMENTARYROCKSARECLSAAIFIEDFURTHERINTO:
*CLASTICROCKES.
*CHEMICALROCKS.
*ORGANICROCKS.

131. APPLIED HYUDRAULICS
¡OPTIMIZATION CRITERIA
lMAX IMPACT FORCE.
lMULIC HORSEPOWER

136. APPLIED HYUDRAULICS
¡Caída De Presión en Toberas
¡Índice de Caballaje Hidráulico

139. Bit Balling
• Cuttings adhere to cutter surface and to
hole bottom.
• Reduces effective length of teeth.
• Occurs in many formations, not just gumbo
shales.
• Balling reduces penetration rate.

148. APPLIED HYUDRAULIC
PRESSUREDROPINTUBES
BITAREA:
p2 2
TFA=4(D)=0.7854(D)
WHERE:0.7854=p/4
D=BITDIAMETER.
JETAREA:
p2TFA=4(D)xN
WHERE:D=NOZZLEDIAMETER
N:NUMBEROFNOZZELSOFSAMEDIAMETER.

149. APPLIED HYUDRAULIC
PRESSURE DROP AT BIT
2 2Pbit= MW x Q/ 10858 x A tob
WHERE:
MW= MUD WEIGH PPG.
Q= FLOW RATE GPM.
10858= CONVERSION CONSTANT.

150. APPLIED HYUDRAULIC
HYDRAULIC POWER INDEX
IHHP = Pbitx Q /1714 x BIT AREA
WHERE:
1714= CONSTANT.

151. APPLIED HYUDRAULIC
OPTIMUMHOLECLEANINGISVERYIMPORTANTDURING
DRILLINGOPERATIONS.
MUDPUMPSPROVIDEFLWORATEANDPRESSURETOACHIEVE
SUCHTASK.
ALSOBITHYDRAULICHORSEPOWERNEEDBEDESIGNEDTO
IMPLEMENTTHETASK
BHPH=PQ/1714
WHER
HPH=HYDRAULICHORSPOWER
P=PRESSUREPSI
Q=FLOWRATEGPM
1714=Constant.

152. APPLIED HYUDRAULICS
AVIALBLESURFACEHORSEPOWER:
MAXSURFACEPRESSUREXALLOWABLEFLOWRATE
FLOWRATERANGEREQUIREDTOCLEANTHEHOLEIS:
Min.-30gal/inOFBITDIAMETER.
Optim.-gal/inOFBITDIAMETER
Max.-gal/inOFBITDIAMETER.

153. APPLIED HYUDRAULICS
DESIGNMETHODS:
1.-HYDRAULICIMPACTFORCE.
2.-BITHYDRAULICHORSEPOWER.
PRESSUREDROPATDIFFERENTFLOWRATESNEEDBE
CALCULATEDINBOTHMETHODES.
THEEDESIGNCRITERIA:
1.-UNLIMITEDSURFACEPRSSURE.
2.-LIMITEDSURFACEPRSSURE.
3.-ALTERNATEOFINTERMEDIATESURFACEPRESSURE
TOCALCULATERPRSSURELOSSESINTHESYTEM:
Pc= KQ 1.80

154. APPLIED HYUDRAULICS
Pc=PRESSURELOSSSESINTHESYSTEMWITHOUTBITPSI.
K=CONSTANT(1714).
Q=FLOWRATEGPM.
WHENSUFRACEPRESSUREISLIMITED,POWERPERCENTAGE
APPLIEDATTHEBITTOOBTAINMAXVALUESARE:
*MAXIMPACTFORCE:HPHb=0.48HPHs.
*MAXHYDRAULKICHORSEPOWER:HPHb=0.65HPHs.

155. DRILLABILITY TEST
¡DETERMINE OPTIMUM OPERATING
CONDITIONS.
¡AS A FUNCTIION OF ROCK STRENGTH.
¡BASED ON TUBULAR ELONGATIONAND
COMPRESSION.
¡EASY APPLICAION.
¡PROCEDURE.

156. DRILLABILITY TEST
*DETERMINEOPTIMUMOPERATINGCONDITIONS
MAXANDMINWOB&RPMBASEDONBITDESIGN.
PREDETERMINEVARIOUSOPERATINGCONDITIONS
E.G.:5TWOB&40RPM,10TWOB&60RPM,15TWOB&80RPM,
30TWOB&100RPM,etc.
MARK1MOFKELLYIN10OR20CMSECTIONS.DRILLVARYING
OPERATINGCONDITIONSASGIVENABOVE;RECORDINGTIME
PERSECTIONMARKED;THISGIVETHEDRILLABILITYTIMES.
THETESTCANBEREPEATEDBYUSINGTHESAMEWOBBUT
WITHDIFFERENTPREDETERMINEDRPMS.
CAHNGINGWOB&RPMUNTILOPTIMUMDRILLINGCONDITIONS
AREACHIEVED.

157. DRILLABILITY TEST
50
5
TIME 1= 5 min
TIME 2= 9 min
TIME 3= 10 min
TIME 4= 6 min
10
15
20
25
30
35
WOB T
60708090100110120130140150RPM

158. PERFORMANCE EVALUATION
¡COSTPERMETER
¡MAXALLOWABLETIME

159. PERFORMANCE EVALUATION
COSTPERMETER
CM=CB+(HV+HT)CE/M
WHERE:
CB=BITCOST($).
HV=TRIPTIME(HR).
HT=DRILLTIME(HR).
CE=RIGCOST($/HR).
M=METERSDRILLED.

160. PERFORMANCE EVALUATION
OBJECTIVE;OBTAINMINCOSTPERMETRDRILLED
WHICHINVOLEVES:
1.-BITCOST.
2.-RIGOPERATINGCOST.
3.-BITEFFECTIVETIMEINHOURS.
4.-TRIPTIMETOCHANGEBIT.
5.-CONNECTIONTIMETHROUGHOUTBITLIFE.
6.-DRILLEDINTERVALBYBIT.

161. PERFORMANCE EVALUATION
COSTPERMETRVS.DRILLINGTIMECURVEISPLOTTED
(AVERAGECOST)
OPTIMUMBITLIFEISDETERMINEDWHENTHECOSTPER
METERSTARTSINCREASING.
DRILLERMUSTCHECKSTRINGWEIGHTATTSHIFTCHANGE
ANDNOTEIFDRAGORSLACKOCCURE.
ALSOBITTORQUE,DECREASEINCIRCULATINGRATEAND
PRESSUREMUSTBECHECKED
ALLTHESEMUSTBERECORDEDEVERYSHIFT.

162. PERFORMANCE EVALUATION
“COST PER METER VS DEPTH CURVE”
5101520253035404550
ROTATING TIME(hrs)
0
7000
6000
5000
4000
3000
2000
1000
DEPTH (M)

163. PERFORMANCE EVALUATION
ROTATING TIME(hrs)
05101520253035404550
7000
6000
5000
4000
3000
2000
1000
DEPTH (M)

164. CUTTING STRUCTRE
InterExterWEAR CHAREC..Localiz.
BEARING /
SEALSGAUGE
OTHER
WEAR
CHARAC.
REASON
POH
12345678
3 WEAR FEATURE (USES ONLY CUTTING STRUCTURE CODE)
* SHOW CONE NUMBER AND LOCATION (4)
*BC –BROKEN CON
BF –BEARING FAILURE
BT –BROKEN TOOTH/CUTTER
BU -BOLD UP BIT
*CC –CRACKED CONE
*CD –CEASED CONE
CI -CONS INTERFERENCE
CR -CROWN
CT –CHIPPED TOOTH/CUTTER
ER -EROSSION
FC –PALIN WEAR
HC –HEAT CRACK
JD –JUNK DAMAGE
*LC –LOST CONE
LN –LOST NOZZLE
LT –LOST TOOTH/CUTTER
Perdidos
OC –ECCENTRIC WEAR
PB ------BIT (Contraída)
PN –PLLUGGED NOZZLE
NO –NON FEATURE WEAR
NR –DO NOT RE-RUN
RG –ROUNDED GAUGE
RR –RE-RUN
RO –“O” ROGo
SD –SKIRT DAMAGE
SS –SELF SHARPENING WEAR
TR -TREAD
WO –WASHE OUT
WT –WORN TOOTH/CUTTER
WEAR & TEAR CODE

165. TRICONE BIT
LOST CONE(LC)
POSSIBLE CAUSES
SEAL FAILURE
EROSION
BOUNCING

166. TRICONE BIT
OFFCENTER (OC)
POSSIBLE CAUSES
OFF CENTER DRILLING
FORMATION CHANGE
BAS STABILIZATION
INADEQUATE WOB

167. TRICONE BIT
WORN TEEETH (WT)

168. TRICONE BIT
LOST INSERTS (LT)
POSSIBLE CAUSES:
MATERIAL FAILIURE.
CONE FRACTURE.

169. TRICONE BIT
0,0,NO,E,I,LN,PP

170. PDC/TSP
JUNK DAMAGE (JD)

171. PDC/TSP
CENTER RING (CR)
POSSIBLE CAUSES:
EXCESSIVE WOB
IMPROPER CLEANING
FORMATION CHANGE

172. PDC/TSP
1,1,LT,A,X,I,ER,BHA

184. BICENTRIC BITS
CONCEPT
GEOMETRY.
DRILLING MODE.

185. BICENTRIC BITS
CONCEPT
1.-SLIMHOLEDRILLINGWITHUNCONVENTIONALHOLE
DIAMETER&GEOMETRY.
2.-LACKOFADVANCEMENTINHYDRAULICHOLLEOPNERS
3.-SONTINGENCYCASINGSTRING(16”,117/8”,11¾”)
MECHANICAL/GEOLOGICALEVENTSREQUIRETHESETTINGOF
ANUNPLANNEDCASINGSTRINGINORDERTOREACH
PLANNEDWELLSOBJECTIVES.

186. BICENTRIC BITS
REAMING L AXIS
DRILLING AXIS

187. GEOMETRY
abc
d
rd
e
rn
rp
a
a.-WELLBORE AXIS
b.-CENTRAL NOMINAL REAMING AXIS.
Rd= DRILLING RADIUS.
Rn= REAMING RADIUS.
Rp=PILOT HOLE RADIUS.
a=1/2 REAMER ARCH

188. GEOMETRY
A
B C
PILOT DIAMETER
STABILIZES BIT DURING DRILLINGA.-
TRIP DIAMETER
DEFINE INTERNAL MIN
DIAMETER FOR WHICH
THE BICENTRIC BIT
CAN PASS.
B.-
BIT MAX DIAMETER.D.-
D
DRILLING DIAMETER
DETERMINE THE
HOLE FINAL
DIAMETER
C.-

189. DRILLING WITH A BICENTRIC BIT
TRIPPING IN CASINGDRILLING
CASING
DIAMETR/PASS
THRU
DRILLING
DIAMETER
PILOTDIAMETER
WELL CENTER
BIT CENTER BITCENTER

190. BICENTRIC BIT
RECOMMENDATIONS
1.-NEEDSAMEATTENTIONASAPDCBIT.
2.-NOROTATIONINSIDECASINGSMALLERTHANTHEBIT
ALLOWS.
3.-CONTROLLEDDRILLING(1-2MIN/M).
4.-“DRILL&OPEN”SIMULATANEOUSLY.THEYARENOTHOLE
OPENERS.
5.-DONOTPLACEASTABILIZERCLOSETOTHEBIT.
6.-HYDRAULICSINACCORDANCEWITHTHEBIIGGEST
DIAMETER.

191. OPERATING PROCEDURE
THE FOLLOWING GENERAL PROCEDURE
MUST BE OBSERVED TO AVOID DAMAGING
BICENTRIC BITS PRIOR TO BREAKING-IN
HAVING IN MIND ACHIEVING MAXIMUM
PERFORMANCE.

192. OPERATING PROCEDURE
¡WELLBOREPREPERATION
¡ITISVERYIMPOLRTANTTOEVAULATEWEARANDTEAROFPRIORBITSTODETERMMINE:
¡JUNKDAMAGE,LOSSOFCUTTERS/TEETH/GAUGE.
¡PERFORMACLEANINGTRIPIFNECESSARY.
¡IFACCESSORIESNEEDBERUNWITHFIXEDBIT,ENSURETHATCASINGFLOATINGEQUIPMENTAREADEQUATE.
¡BITPREPERATION.
¡USEARUBBER/WOODMATWEHNMAKINGUPTHEBIT.
¡INSPECTCUTIINGSTRUCTURETODETERMINEPREMATIUREDAMAGE.
¡INSPECTINSIDEOFTHEBITFOREXTERNALOBJECTS.
¡VERIFYBITMARKINGASPERAPISTANDARDS.
¡VERIFYNOZZELSAREFIRMLYSETANDOFTHEPROPERTYPEASPERBITMARKING.

193. OPERATING PROCEDURE
¡BITMAKEUP
¡HANDLEWITHCARE,USEAWOODORRUBBERMAT.
¡ADJUSTMAKEUPTONGS.USEASPERTYPE,SIZEANDSPECS.NEVERUSEDCASTINGTOOLS.
¡CLEANANDLUBRICATECONNECTION
¡CAREFULLYRUNTHESTRINGANDALIGNCONNECTIONS.
¡MAKEUPBITANDBASKETAPPLYINGRECOMMENDEDTORQUE.
¡TRIPPINGINHOLE
¡REMOVEMAKEUPTOOLS,AND
CAREFULLYRUNTHEBITTHRU
RT.
¡WHENPASSINGTHRU&BOPS,
SHOES,TOL,USEA2M/MIN
RUNNINGSPEED.
¡ATTENTIONTODRAGPOINTS
NOTEDINPREVIOUSTRIPS.
¡IFREAMINGISNEEDEDUSE
WOBOF0.5T&35RPM.EL
USEOFOTHERHIGHER
CONDITIONSMAYDAMAGER
THEBITCUTTINGSTRUCTURE
ANDBEARINGREMEMBER:
THESEBITSARENOTFOR
REAMING.

194. OPERATING PROCEDURE
¡TRIPPINGTOBOTTOM
¡CAREFULLYTRIPINTHRUDOGLEGS,TIGHTHOLES&OTHERSEVERITIES
¡AMPLYCIRCULATE&ROTATEAT40-60RPMFORTHELA.STTHREEOFFBOTTOMMETERS
¡TAGBOTTOMCAREFULLY,VERIFYTHEWEIGHT&TORQUEINDICATORS.
¡PICKUP0.5MOFFBOTTOM
¡CIRCULATE5-10MINSPRIORTOBITBREAKINTOPREPARETHEnewWELLBOREPATTERN.
¡BOTTOMHOLEPREPERATION.
¡SLACKOFFBITWITHAMPLECIRCULATIONRATE.
¡ESTABLISHTHENEWDRILLINGPATTERNBYAPPLYING40-60RPM&1-2TWOB.
¡VERIFY&RECORDSPM&PUMPPRESSURE.
¡STARTDRILLINGWITHABOVEPARAMETERSFOR1M.
¡INCREASEWOBIN1TSTEPSUNTILREACHINGDESIREDWOB.
¡INCREASERPMTODESIREDVALUE.

195. OPERATING PROCEDURE
¡DRILLING
¡ESTABLISHCORROSIVEINTERVALCORRELATIONS,REDUCERPMTOAVOIDPREMATURECUTTINGSTURCTUREDAMAGE.INCASEOFFIXEDCUTTERBITS,INCREASEFLOWRATEANDDECREASEWOB.
¡PERFORMDIRLLABILITYTESTSREPEATEDLYTOSTABLISHACONSTANTROPPATTERN.USEOFCONSTANTRPN&WOBTHRUAGIVENFORMATIONTYPEMAYCAUSEPREMATUREBITDAMAGE.
¡DRILLING.
¡UPONMAKINGACONNECTION:
¡STARTPUMPINGATDESIRTEDFLOWRATEININCREMENTSOF20SPM.VERIFYANDRECORDPUMPPRESSURE.
¡TAGBOTTOMTHENAT0.5MOOFFBOTTOMCIRRCULATEATFULLFLOWRATEFOR5-10MIN.
¡RESUMEDRILLINGASINDICATEDININITIALPREPERATIONS.
¡NEVERIMPACTBITONBOTTOMWITHALLSTRINGWEIGTH.

196. OPERATING PROCEDURE
¡TRPPINGOFFBOTTOM
¡ATENDOFBITLIFE:
¡CIRCULATEWITHFULLFLOWRATEFOR2-4HOURS.
¡PICKUPBITOFFBOTTOM,WATCHFORDRAG/OVERPULL.NOTESUDDENCHANGEINWEIGHTTOAVIDTIGHTHOLES.
¡DECREASEPULLOUTSPEEDWHENPASSINGTHRURESTRICTIONSMTOL&BOPS.
¡DISCONNECTBITASPERPROCEDURESFORMAKEUP.
¡WEARTEAREVALUATION.
¡SETBITWITHCUTTINGSTRUCTURELOKKIUNGUPWARDS.
¡WASHBITTOREMOVEALLADHEREDMATERIALS.NEVERIMPACTPITTOELIMINATECUTTINGSOROTHERMATERIALS.
¡EVALUATEWEAR&TEARASPERTHE7DIGIOTESCODE.ATTKEEPINMINDETHATTHISISTHEONLYINDICATIONYOUHAVEFROMTHEBOTTOMOFTHEWELLBORE.
¡SELECTTHENEXTBITTYPEASPERWEARANDTEARANDFORMATIONTYPE.

197. OPERATING PROCEDURE
API CONNECTIONS & MAKE UP TORQUE
BIT DIAMETER
(in)
API CONNECTION
(in)
RECOMMENDED
Torque (ft-lb)
3 ¾-4 ½2 3/8 Reg1800-3085
4 5/8-52 7/8 Reg3075-4650
5 1/8-7 3/83 ½ Reg5175-7660
7 5/8-94 ½ Reg12450-17750
9 ½-14 ½6 5/8 Reg37100-38500
14 ½-267 5/8 Reg48300-60900