bits
TRANSCRIPT
CASING
Drilling Bits
Objectives
At the end of this training session, you will be able to:
� List the different type of bits
� Describe the different rock failure mechanism
� Describe the IADC (International Association of Drilling Contractors) bit coding and dull bit gradingContractors) bit coding and dull bit grading
� Describe the effect of change in weight on bit, rpm, hole size, mud weight and solids content on bit performance
Introduction
Drilling bits selection is crucial to the performance of all drilling projects.
Understanding the different types of bits and their respective applications is a pre-requisite to bit selection.
Not only the right bit in the right application but also running it with the right operating parameters.the right operating parameters.
Well engineers must stay abreast of the latest developments to ensure optimum bit selection.
Bit TypesBit Types
Bit Types
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
PDC (Polycrystalline Diamond Compact)
Drill Bits
FixedCutter
RollerCone
� Use artificially made diamonds
� Run successfully with downhole motors
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
PDC bit: Elements
1. synthetic diamond cutters
2. support structures for the cutters
3. gauge protection
1
3
2
5
2
Courtesy of
3. gauge protection inserts
4. Depth of cut limiters
5. nozzles.
Steel / Tungsten Carbide
PDC bit: Body Material
� Steel body in one piece
⇒ High precision⇒ simple repair⇒ no weld
� Tungsten Carbide matrix on steel shell
⇒ Erosion resistant
8 mm11 mm13 mm16 mm19 mm
PDC bit: Cutting Elements
BLADE
Courtesy of
PDC CUTTER
γγγγ
Natural Diamond
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Diamond Bit Profiles
Shallow coneParabolicTaper or Double cone
Soft formation=> => => => => Hard formation(More diamond coverage)
Low ROP
Diamond bit : Design
� Size and spacing of diamonds determines its use� Widely spaced diamonds : large pieces of soft sand and shale� Medium spacing of large diamonds: wide range of sand, shale ,
limestone� Smaller diamonds set in close pattern: hard formations� Smaller diamonds set in close pattern: hard formations
Natural Diamond bit: Elements
� Natural Diamonds = hardest mineral
� But brittle and Temp dependant
� Fluid circulation important
Courtesy of
� No cone , operates like a single unit
� Sensitive to shock and variation
TSP (Thermally Stable Polycrystalline)
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Cutting Elements - TSP
� TSP
Courtesy of
Impregnated Diamond
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Impregnated Diamond: Blades� Formation: medium
hard to very hard, ABRASIVE!
� Impregnated cutting element.
� Distributed in a tungsten carbide matrix.
Bit Blade Matrix
Courtesy of
matrix.� During heating
(furnace) the Segments are bonded to the bit body.
Diamond Grit
Cutting Elements - Impregnated
� Impregnated Diamond Blades
Courtesy of
ROLLER CONE
Alternative Names
Rock Bit
Drill Bits
FixedCutter
RollerCone
Rock BitTri-Cone™
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Basic Types Of Roller Cone Bits
Insert Bits
� Tungsten Carbide Bits
� Button Bits
Tooth Bits
� Mill Tooth Bits
Cone #3
Shirttail
Heel Row
Gauge Row
Cone #1
Cone #2
Inner Row
Nose
Roller Cone Components
Pin
Shirttail Lug
Bit Body
Nozzle
Roller cone bits: Nozzles
SHROUDEDTYPE
STANDARDTYPE
Mill Tooth Bits
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Cutting Elements – Mill Tooth
� Teeth and Hardfacing
Courtesy of
Insert Bits
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Cutting Elements - Insert
� Tungsten Carbide Inserts
Courtesy of
Tricone Bit - Roller Bearing
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Roller Cone Bearing Systems
Main Bearings Retention Bearings Seals
Journal Bearing
Bit
Roller Bearing
Bit
Tricone Bit - Roller Bearing
Retention Bearing
Main Bearing
Courtesy of
Thrust Bearing
Pin Bearing
Tricone Bit - Journal Bearing
Drill Bits
FixedCutter
RollerCone
InsertMill ToothDiamondP D C
NaturalDiamond
ImpregnatedDiamondT S P
RollerBearing
JournalBearing
Courtesy of
Retention Bearing
Main Bearing
Tricone Bit - Journal Bearing
Thrust Bearing
Pin Bearing
Rock Failure MechanismsRock Failure Mechanisms
Failure Mechanisms
Failure Mechanisms
� Shear FailurePDC BITPDC BIT
CONTINUOUSCONTINUOUSSHEARINGSHEARING
� Compressive
ROLLER CONE BITCYCLIC COMPRESSION
� Compressive Failure
Courtesy of
Drilling Mechanisms
� Shear/Compressive Failure
NATURAL DIAMOND
OR IMPREG BIT
CONTINUOUS
CRUSHING
& ABRASION
Courtesy of
Drilling Mechanisms vs Bit Type
Scraping Mill Tooth
Chipping and Crushing Insert
Shearing PDCShearing PDC
Ploughing / Grinding Natural/Impregnated Diamond
Courtesy of
IADC Bit ClassificationIADC Bit Classification
IADC Classification – Roller Cone517G
Soft Formations w ith Low Compressive Strength and High
Drillability
1
Medium to Medium Hard Formations w ith
High Compressive Strength
2
Hard Semi-Abrasive and Abrasive 3
STEEL TOOTH
BITS
Cutting Structure Series Cutting Structure Type (1 to 4)
1 refers to the softest formation in a
particular Series and 4 refers to the
hardest formation within the Series
Bearing/Gauge Description
Standard Roller
Bearing1
Roller Bearing Air
Cooled2
Roller Bearing 3
Features Available (Optional)
A - Air ApplicationB - Special Bearing SealC - Center JetD - Deviation ControlE - Extended NozzlesG - Gauge/Body Protection
Ref: SPE 23937 The IADC Roller Bit Classification System
8-1/2” EHP 51
and Abrasive Formations
3Soft Formations w ith Low Compressive Strength and High
Drillability
4
Soft to Medium Formations w ith Low Compressive Strength
5Medium Hard
Formations w ith High Compressive Strength
6Hard Semi-Abrasive
and Abrasive Formations
7Extremely Hard and Abrasive Formations 8
INSERT BITS
within the SeriesGauge
Protected
3
Sealed Roller
Bearing4
Sealed Roller Brg -
Gauge Protected
5
Sealed Friction Bearing
6Sealed
Frction Brg Gauge
Protected
7
ProtectionH - Horizontal Steering Appl.J - Jet DeflectionL - Lug PadsM - Motor ApplicationS - Standard Steel ToothT - Two Cone BitW - Enhanced Cutting StructureX - Predominantly Chisel Tooth InsertY - Conical Tooth InsertZ - Other Shape Insert
IADC Classification – Fixed Cutter
12-1/4” DS66H
M432Body Material Steel or Matrix.
Cutter Density PDC: 1 to 4, diamond bits: 6 to 8(the lower the number, the lighter set the bit).
Cutter Size/Type For PDC cutter, 1 indicates >24 mm, 2 is between 14 and 24 mm, 3 is between 8 and 14 mm and 4 is smaller than 8. For diamond bits, 1 represents
Ref: SPE 23940 Development of a New IADC Fixed Cutter Drill Bit Classification System
Profile The final digit indicates the general body style and varies from 1 (flat profile) to 4 (long flanked turbine style).
Fixed cutter IADC codes are intended only to provide a means for characterizing the general physical appearance of fixed cutter drill bits. Unlike the IADC classification for roller bits, these codes do not represent an application guideline.
and 4 is smaller than 8. For diamond bits, 1 represents natural diamond, 2 is for TSP, 3 is a combination of natural diamond and TSP and 4 is for impregnated.
Soft
IADC CodesTooth
2
1
1-1
Hard
2
31-3
2-1
Soft
4
Tooth
Insert
IADC Codes
2
14-1
Hard8
7
6
5
2
3
8-3
Soft
1
4
Tooth
Insert
2
1
PDC
IADC Codes
Hard 8
7
6
4
5
2
3
Soft
4
Tooth
Insert
IADC Codes
2
1
PDC
Hard8
7
6
4
5
Diamond
2
3
Soft
1
4
Tooth
Insert
2
1
IADC CodesPDC
Hard8
7
6
4
5
2
3Impregnated
Diamond
Diamond
IADC Bit Dull Grading CodeIADC Bit Dull Grading Code
IADC Bit Dull Grading Code
The International Association of Drilling Contractors has developed a standard methodology for describing used bits. This information is essential for detailed bit performance analysis.
The methodology is composed of an 8 character code The methodology is composed of an 8 character code that describes bit wear and the reason why the bit was pulled.
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
Fixed Cutter Bits
The cutting structure is graded from 0 to 8 depending on the proportion of cutting structure lost (0 = Intact, 8 = 100% worn).
Roller Cone Bits
0 1 2 3 4 5 6 7 8
Inner Cutting Structure (All Inner Rows)
Outer Cutting Structure (Gauge Row Only)
0 1 2 3 4 5 6 7 8
Cone 2Cone 3
Cone 1
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion
*BC - Broken ConeBF - Bond FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow Passage
Fixed Cutter Bits Roller Cone Bits
ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics
*CC - Cracked Cone*CD - Cone DraggedCI - Cone InterferenceCR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
PN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4
Note that this is for the Primary dull characterist ics.
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Fixed Cutter – Main Wear Characteristics
NO WEAR(NO)
WORNCUTTER
(WT)
BROKENCUTTER
(BT)
LOSTCUTTER
(LT)
EROSION(ER)
POST OR STUDCUTTERS
BONDFAILURE
(BF)
NO WEAR(NO)
WORNCUTTER
(WT)
BROKENCUTTER
(BT)
LOSTCUTTER
(LT)
CYLINDERCUTTERS BOND
FAILURE(BF)
Courtesy of
Dull Characteristics – Some Examples
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter
Fixed Cutter Bits
LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics BU - Balled Up
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4BU – Balled Up Bit
(primary)CD – Cone Dragged
(secondary)Ref : IADC Drilling Manual – Eleventh Edition
Dull Characteristics – Some Examples
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter
Fixed Cutter Bits
LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics CT – Chipped Cutter
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Dull Characteristics – Some Examples
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter
Fixed Cutter Bits
LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics
LT – Lost Cutter
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4BT – Broken Teeth/Cutters
Ref : IADC Drilling Manual – Eleventh Edition
Dull Characteristics – Some Examples
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter
Fixed Cutter Bits
LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics
RO – Ring Out
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4JD – Junk Damage
Ref : IADC Drilling Manual – Eleventh Edition
Dull Characteristics – Some Examples
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter
Fixed Cutter Bits
LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics
WT – Worn Cutters
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4SD - Shirttail Damage
Ref : IADC Drilling Manual – Eleventh Edition
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4
TR - Tracking
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4SS – Self Sharpening Wear
Ref : IADC Drilling Manual – Eleventh Edition
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone Interference
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out
Roller Cone Bits
Dull Characteristics – Some Examples
CR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4ER – Erosion
Ref : IADC Drilling Manual – Eleventh Edition
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
Fixed Cutter Bits Roller Cone Bits
N - Nose RowM - Middle RowG - Gauge Row
Cone 1, 2 or 3
C - Cone N - NoseT - Taper S - ShoulderG - Gauge
G - Gauge RowA - All Rows
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
Fixed Cutter Bits Roller Cone Bits
This box is for roller cone bits. Fixed cutter bits will always be designated by "X".
A linear scale estimating bearing life used. (0 -No life
Non Sealed Bearings
bearing life used. (0 -No life used, 8 - All life used, i.e., no bearing life remaining.)
Sealed Bearings
E - Seals EffectiveF - Seals FailedN - Not Able to Grade
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
For all Bits
The letter “I” is used to designate bits that are in gauge.
If the bit is under gauge, the amount is recorded to the nearest 1/16” of If the bit is under gauge, the amount is recorded to the nearest 1/16” of an inch. For example, if the bit is 1/8” under gauge, this is reported as 2/16 or often only as 2.
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
BF - Bond Failure BT - Broken Cutters BU - Balled Up CT - Chipped Cutters ER - Erosion
*BC - Broken ConeBF - Bone FailureBT - Broken Teeth/CuttersBU - Balled Up Bit
LN - Lost NozzleLT - Lost Teeth/CuttersOC - Off-Center WearPB - Pinched Bit
Fixed Cutter Bits Roller Cone BitsThis is for the Secondary dull char. and it uses the same codes as for the Primary dull char.
ER - Erosion HC - Heat Checking JD - Junk Damage LN - Lost Nozzle LT - Lost Cutter NR - Not Rerunable PN - Plugged Nozzle RG - Rounded Gauge RO - Ring Out RR - Rerunable SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Cutters NO - No Dull Characteristics
BU - Balled Up Bit*CC - Cracked Cone*CD - Cone DraggedCI - Cone InterferenceCR - CoredCT - Chipped Teeth/CuttersER - ErosionFC - Flat Crested WearHC - Heat CheckingJD - Junk Damage*LC - Lost Cone
PB - Pinched BitPN - Plugged Nozzle/Flow PassageRG - Rounded GaugeRO - Ring Out SD - Shirttail DamageSS - Self Sharpening WearTR - TrackingWO - Washed Out BitWT - Worn Teeth/CuttersNO - No Dull Characteristic
* Show Cone under Location 4
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
IADC Bit Dull Grading Code
INNER ROWS
OUTERROWS
DULL CHAR
LOCA-TION
BRNG/ SEALS
GAUGE 1/16”
OTHER CHAR
REASON PULLED
Cutting Structure RemarksB G
For All Bits
BHA - Change Bottom Hole Assembly DMF - Down hole Motor Failure DSF - Drill String Failure
HP - Hole Problems HR - Hours PP - Pump Pressure DSF - Drill String Failure
DST - Drill Stem Test DTF - Down hole Tool Failure RIG - Rig Repair CM - Condition Mud CP - Core Point DP - Drill Plug FM - Formation Change
PP - Pump Pressure PR - Penetration Rate TD - Total Depth/Casing Point TQ - Torque TW - Twist Off WC - Weather Conditions WO - Washout -DrillString
Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Key to Dull Bit Grading: Grade a Lot of Dulls !
Photo courtesy of
BIT RECORD
Well : BIT RECORDDate :
Bit DataBHA Bit Size Bit type Serial IADC Nozzles Depth Depth Drilling ROP Bit krevs WOB Rot Flow Press Inc Mud Total Total Total DullNo. No. (inch) & maker Number Code (1/32") IN (m)OUT (m) Time (m/hr) (drilling) (Klbs) (RPM) (GPM) (psi) (deg) SG mtr hrs krevs I O D L B G O R
Run Data Bit life Grading
To be filled up at wellsite
No. No. (inch) & maker Number Code (1/32") IN (m)OUT (m) Time (m/hr) (drilling) (Klbs) (RPM) (GPM) (psi) (deg) SG mtr hrs krevs I O D L B G O R
1 1 16 T11C L15264 1153 x 18, 1
x 1615 420 18.04 22.45 151.50 10-25 120 820 1450 0 1.07 405 18.04 152 0 1 WT A E I NO TD
2 2RR 12 1/4 DSX113 204556 PDC 8 x 13 420 422 0.50 4.00 1.22 2-10 60 680 1000 0.00 1.15 2 0.50 1 0 1 WT S X I CTBHA
4 2RR2 12 1/4 DSX113 204556 PDC 8 x 13 1408 1714 16.54 18.50 119.09 25-35 120 820 1900 1.00 1.19 308 17.04 120 1 3 WT A X I PN TD
•BHA nb does not always = bit nb
•Drilling time = bit time on bottom ( ←←←← Mud loggers)
•Krevs = 1000 bit revolution ( ←←←← Mud loggers)
Drilling Parameters vs Bit PerformancePerformance
Bit performance
� Main function: ROP and longevity
� Drilling fluid is circulated through passageways in the bit to remove cuttings and apply hydraulic power to improve ROPROP
� ROP is a function of WOB, RPM, mud properties and hydraulic efficiency
Chip Formation� Tooth load overcomes rock compressive strength,
generates crater
� Scraping helps to remove chips from craters.
CutterCutterCutterCutter
FormationFormation
Borehole pressure causes chip hold down effect
Courtesy of
ROP vs OverbalanceData based on 7-7/8” bit with 30 klbs at 60 RPM
Courtesy of
Chip Removal� Removal of chips is required to
allow for new chip formation
CutterCutter
Hydraulics help to remove chips
FormationFormation
CutterCutter
72 Courtesy of
CHIP CREATION CHIP REMOVAL
WOB (Weight on Bit) ResponseR
OP
WEIGHT on BIT0
0
Courtesy of
CHIP CREATION CHIP REMOVAL
RPM ResponseR
OP
RPM0
0
Courtesy of
Effects of Offset or Skew
– 0º - 2º– Reduced Gage Scraping– More Durable– Slower Drilling– Abrasive / Hard Formations
Reduced Offset– 3º - 5º– Increased Gage Scraping– Less Durable– Faster Drilling– Soft / Sticky Formations
Increased Offset
Courtesy of
Cone Profiles
Flat Cone Profile– Minimum Bottom Scraping– More Durable– Slower Drilling– Abrasive / Hard Formations
Round Cone Profile– Increased Bottom Scraping– Less Durable– Faster Drilling– Soft / Sticky Formations
Tooth Cutter Design
Faster DrillingLess Durable
Slower DrillingMore Durable
Insert Cutter Design
HP83HP51
Faster DrillingLess Durable
Slower DrillingMore Durable
Cutting Structure ComparisonsHP83EHP41H
Faster DrillingLess Durable
Slower DrillingMore Durable
Tooth & Insert Cutter Designs
Soft Formation
• Fewer Teeth• Longer Teeth• Bigger Teeth• Sharper Teeth
Hard Formation
• More Teeth• Shorter Teeth• Smaller Teeth• Duller Teeth• Sharper Teeth
• Sharp Profile• Fracture-Resistant Tooth
Material
• Faster Drilling• Less Durable
• Rounded teeth • Flat Profile• Wear-Resistant Tooth
Material
• Slower Drilling• More Durable
Bit SelectionBit Selection
Bit Application SpectrumP
enet
ratio
n R
ate
PDC
Mill ToothInsert
DP
Formation Compressive Strength
Pen
etra
tion
Rat
e
Insert
Impreg& NaturalDiamond
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Bit Selection Process
Which Which Which Which One ?One ?
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Bit Selection - PDC
Advantages� Very Fast ROP� Long Life Potential
ConsiderationsConsiderations� Impact Damage� Abrasiveness� Stability
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Bit Selection – Tooth Bit
Advantages� Fast ROP� Good Stability� Economic
Considerations� Tooth Wear Rate� Bearing Life
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Bit Selection – Insert Bits
Advantages� Cutting Structure Durability� Range of Formations� Interbed Tolerance� Steerability and Stability� Steerability and Stability
Considerations� Slower ROP� Bearing Life
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Bit Selection – Natural & ImpregDiamond Bits
Advantages� Very Durable� Hard Rock Capability� Low Junk-in-Hole Risk
Considerations� Slower ROP� RPM Sensitivity� High Cost Applications
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Gauging Procedures for 3-Cone BitsSmith 3-Cone Bits are designed to have minimum gauge contact. By use of suitable gauge cutting structure design and materials, the “minimum gauge”configuration improves penetration rates whilst maintaining full size hole. Only the cutting elements (teeth or inserts) contact, while the cone shell steel isheld away from the hole wall. This means that unless the gauge cutting elements are “lined up” with the gauge contact point on any gauge ring, the bit willmeasure slightly smaller than it actually is. This is particularly true of aggressive insert bits which have a lighter set gauge and large offset.
Gauging a 3-cone bit, either sharp or dull, requires some care and should be carried out as follows:
1. Only use a calibrated 3-cone gauge ring measuring the nominal bit size.2. Turn the bit on its pin and rotate all the cones to their “maximum gauge point”so that a gauge tooth or insert lines up at this point.
3. Place the gauge ring over the bit at the maximum gauge points.4. Pull the ring gauge tight against the gauge elements on two cones.5. Measure any gap at the free cone. This is not the the correct value for gauge wear.6. To calculate the actual gauge wear you must multiply the gap distance by 2/3 (‘two thirds’).For example: if measured gap is 3/16” then multiply by 2/3 giving 2/16” under-gauge.
7. Record the bit as being either in gauge or the amount under-gauge. Although IADC say to use
Gap
7. Record the bit as being either in gauge or the amount under-gauge. Although IADC say to usean “I” for in gauge, we recommend using a 0 (zero) to avoid the confusion between an I and a 1.
Maximum gauge point
API Sizes for New Bits API Roller Cone Bit Tolerances
Bit Size Actual Size Bit Size ToleranceMin. Max.
26” 26.000” 26.094” 3-3/8” to 13-3/4” +1/32”, -0”
23” 23.000” 23.094” 14” to 17.5” +1/16”, -0”
17.5” 17.500” 17.562” 17-5/8” and larger +3/32”, -0”
16” 16.000” 16.062”
12.25” 12.250” 12.281”
8.5” 8.500” 8.531”
6” 6.000” 6.031”
Important points to note:
A 3-Cone bit can be built larger than nominal size because of the plustolerance allowed, but a new bit can never be undergauge (due to therequired cutting structure clearances).
To gauge a new bit you must use a 3-cone ring gauge that measures thenominal bit size plus API tolerance (see table). You CANNOT use a PDC ringgauge to gauge a 3-cone bit and vice versa.
On those Smith 3-Cone bits that feature the ‘OD’ diamond enhanced heel rowinserts (e.g. MSDGHOD), these bits are designed and built so that theseinserts actively cut gauge at the maximum gauge point.Therefore, if the gauge cutting elements are worn and undergauge, then re-gauge the bit on the heel row inserts.
The manufacturing locations of Smith 3-Cone bits are all ISO Certified (ISO9001).
Gauging Procedures for PDC Bits
Gauging a PDC bit, either sharp or dull, requires some care and should be carriedout as follows:
1. Only use a calibrated PDC “No-Go” gauge ring.2. Turn the bit on its pin.3. Place the No-Go gauge ring over the bit - it should stop at the gauge skimmer/gaugepads4. If the No-Go PDC gauge ring will not pass over the entire gauge area of the bit then thebit is in gauge.5. If the No-Go gauge ring will pass then place the ring gauge at the gauge pads and pullhard to one side.6. Measure the gap in 1/16” at the point opposite the point of contact between ring gaugeand gauge pad.7. Record the bit as being either in gauge or the amount under-gauge. Although IADC say to
PDCBit
No-Go gauge ring pulledhard against gauge pad.
No-Go ring gauge
7. Record the bit as being either in gauge or the amount under-gauge. Although IADC say touse an “I” for in gauge, we recommend using a 0 (zero) to avoid the confusion between an Iand a 1.
API PDC Bit Tolerances
Bit Size Tolerance
6 3/4” and smaller -0.015” to + 0”
6 25/32” and including 9” -0.020” to + 0”
9 1/32” and including 13 3/4” -0.030” to + 0”
13 25/32” and including 17 1/2” -0.045” to + 0”
17 17/32” and larger -0.063 to + 0”
Important points to note:
A PDC bit can be built slightly smaller than nominal size because ofthe negative tolerance allowed, but a new bit should never beovergauge.
To gauge a bit you must use a PDC “No-Go” ring gauge that measuresthe nominal bit size minus API tolerance (see table). You CANNOTuse a 3-cone ring gauge to gauge a PDC bit and vice versa.
The manufacturing locations of Smith PDC bits are all ISO Certified(ISO 9001).
Measure the gap here in 1/16” and record
Casing /DriftDiameter
Drill Diameter
Hole Center
Bit Center Bit Center
Bi-center Bit
Tripping through Casing / During Drill out
Drilling Ahead
Diameter
Pilot Diameter
Drill Out Mode
� During drill out, drift & drill bits rotate around the drift axis
� The drift axis is at the geometric center of the reamer
When drilling ahead, drift & drill bits rotate around the drill axis
The drill axis is defined as the center of the pilot section,
Drilling Ahead
center of the pilot section, and is also the center of the bit connection / shank
Quad-D Nomenclature
12 1/4” x 14 3/4” QDS41PX
Drift Diameter Enhanced Gage Protection
Drill DiameterNumber Range Cutter Size
02-07 6mm08-27 9mm28X 11mm
29-59 13mm60-81 16mm82-97 19mm98X 22mm99X 25mm
QDS: QUAD-D Steel BitQDM: QUAD-D Matrix BitQDG: QUAD-D Reamer
Protection(standard on all steel bits)
Pilot Conditioning
Drift Diameter
Drill Diameter
Dual Diameter Reamer
Geometry
9 7/8”
8 1/2”
= 6 3/4”
Pilot Bit Diameter
Pilot Bit Diameter
Pilot ConditioningSection Diameter
8 1/2” x 9 7/8”QDG76 example
6 1/2”
= 6 3/4”
= 6 1/2”