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Brocas IADC

The document discusses various classification systems and codes used for drill bits, including: - The IADC classification system for roller cone bits based on formation type and drilling application. - The IADC dull grading code which uses an 8 character code to describe bit wear and reason for removal. - Common dull characteristics coded in the IADC system for both fixed cutter and roller cone bits such as worn cutters, broken teeth, erosion and more. - Examples of various dull characteristics codes and their meanings.

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Bits and Holemaking IPM Bits and Holemaking DRILLING PRACTICES
Bits and Holemaking IPM IADC Bit Classification
Bits and Holemaking IPM IADC Classification – Roller Cone Ref: SPE 23937 The IADC Roller Bit Classification System 8-1/2” EHP 51 517G 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 Formations 3 Soft Formations w ith Low Compressive Strength and High Drillability 4 Soft to Medium Formations w ith Low Compressive Strength 5 Medium Hard Formations w ith High Compressive Strength 6 Hard Semi-Abrasive and Abrasive Formations 7 Extremely Hard and Abrasive Formations 8 INSERT BITS 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 Bearing 1 Roller Bearing Air Cooled 2 Roller Bearing Gauge Protected 3 Sealed Roller Bearing 4 Sealed Roller Brg - Gauge Protected 5 Sealed Friction Bearing 6 Sealed Frction Brg Gauge Protected 7 Features Available (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
Bits and Holemaking IPM Soft Hard IADC Codes Tooth 2 1 3 1-1 1-3 2-1 IPM
Bits and Holemaking IPM Soft Hard 8 7 6 4 5 Tooth Insert IADC Codes 2 1 3 8-3 4-1 IPM
Bits and Holemaking IPM Soft Hard 1 8 7 6 4 5 Tooth Insert 2 1 3 PDC IADC Codes IPM
Bits and Holemaking IPM Soft Hard 8 7 6 4 5 Tooth Insert Diamond IADC Codes 2 1 3 PDC IPM
Bits and Holemaking IPM Soft Hard 1 8 7 6 4 5 Tooth Insert 2 1 3 Impregnated Diamond IADC Codes Diamond PDC IPM
Bits and Holemaking IPM IADC Bit Dull Grading Code
Bits and Holemaking IPM 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 that describes bit wear and the reason why the bit was pulled. INNER ROWS OUTER ROWS DULL CHAR LOCA- TION BRNG/ SEALS GAUGE 1/16” OTHER CHAR REASON PULLED Cutting Structure RemarksB G
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 Inner Cutting Structure (All Inner Rows) Outer Cutting Structure (Gauge Row Only) 0 1 2 3 4 5 6 7 8 Cone 2 Cone 3 Cone 1 IPM Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 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 *BC - Broken Cone BF - Bond Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Fixed Cutter Bits Roller Cone Bits Note that this is for the Primary dull characteristics. Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM Fixed Cutter – Main Wear Characteristics NO WEAR (NO) WORN CUTTER (WT) BROKEN CUTTER (BT) LOST CUTTER (LT) EROSION (ER) POST OR STUD CUTTERS NO WEAR (NO) WORN CUTTER (WT) BROKEN CUTTER (BT) LOST CUTTER (LT) CYLINDER CUTTERS BOND FAILURE (BF) BOND FAILURE (BF) Courtesy of
Bits and Holemaking IPM 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 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 Fixed Cutter Bits BU - Balled Up Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples BT – Broken Teeth (primary) CD – Cone Dragged (secondary)Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM 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 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 Fixed Cutter Bits CT – Chipped Cutter Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM 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 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 Fixed Cutter Bits LT – Lost Cutter Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples BT – Broken Teeth/Cutters Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM 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 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 Fixed Cutter Bits La RO – Ring Out Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples JD – Junk Damage Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM 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 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 Fixed Cutter Bits WT – Worn Cutters Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples SD - Shirttail Damage Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples TR - Tracking
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples SS – Self Sharpening Wear Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples ER – Erosion Ref : IADC Drilling Manual – Eleventh Edition
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS DULL CHAR LOCA- TION BRNG/ SEALS GAUGE 1/16” OTHER CHAR REASON PULLED Cutting Structure RemarksB G    Fixed Cutter Bits Roller Cone Bits C - Cone N - Nose T - Taper S - Shoulder G - Gauge N - Nose Row M - Middle Row G - Gauge Row A - All Rows Cone 1, 2 or 3 Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 used, 8 - All life used, i.e., no bearing life remaining.) Non Sealed Bearings Sealed Bearings E - Seals Effective F - Seals Failed N - Not Able to Grade Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 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
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 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  *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Fixed Cutter Bits Roller Cone Bits This is for the Secondary dull char. and it uses the same codes as for the Primary dull char. Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
Bits and Holemaking IPM IADC Bit Dull Grading Code INNER ROWS OUTER ROWS 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 DST - Drill Stem Test DTF - Down hole Tool Failure RIG - Rig Repair CM - Condition Mud CP - Core Point DP - Drill Plug FM - Formation Change HP - Hole Problems HR - Hours 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
Bits and Holemaking IPM Key to Dull Bit Grading: Grade a Lot of Dulls ! Photo courtesy of
Bits and Holemaking IPM BIT RECORD Well : BIT RECORD Date : Bit Data BHA Bit Size Bit type Serial IADC Nozzles Depth Depth Drilling ROP Bit krevs WOB Rot Flow Press Inc Mud Total Total Total Dull 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 115 3 x 18, 1 x 16 15 420 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 Run Data Bit life Grading To be filled up at wellsite •BHA nb does not always = bit nb •Drilling time = bit time on bottom (← Mud loggers) •Krevs = 1000 bit revolution (← Mud loggers)
Bits and Holemaking IPM Drilling Parameters vs Bit Performance
Bits and Holemaking IPM DIFFERENTIAL PRESSURE AT BIT Erosion Depth of Cut Wash out Worn CuttersWOB Flow Rate Drilling Problem Identification
Bits and Holemaking IPM CIRCULATING PRESSURE (standpipe pressure with bit off bottom) Nozzles Restriction Wash out PumpsMud Weight Flow Rate Mud Properties Air in Mud Drilling Problem Identification
Bits and Holemaking IPM TORQUE WOB Hole Angle Wash out FormationMud Weight Hole Cleaning Mud Properties Junk Bit Related RPM Reaming Dry Drilling Drilling Problem Identification
Bits and Holemaking IPM RATE OF PENETRATION RPM/WOB Hole Angle Wash out FormationOverbalance Hydraulics Bit RelatedJunk Drilling Problem Identification
Bits and Holemaking IPM Condition of Dull Bit Possible Causes Possible Remedies Excessive bearing wear Excessive rotary speed Excessive rotating time Excessive WOB Excessive sand in circulating system Un-stabilised drill collars Improper bit type Slower rotary speed Reduced rotating hours Lighter WOB Removal of sand from circulating fluid Stabilise drill collars Use harder formation bit type with stronger bearing structure Excessive broken teeth Improper bit type Improper break-in procedure used for new bit Excessive WOB for type used Use harder formation bit type having more teeth Proper break-in procedure used for new bit Lighter WOB Unbalanced tooth wear Improper bit type Improper break-in procedure used for new bit Use of different bit type based upon the rows of teeth which are excessively worn on the dull bit Proper break-in procedure used for new bit Excessive tooth wear Excessive rotary speed Improper bit type Use of nonhardfaced type Slower rotary speed Use of harder formation bit type having a greater number of teeth Use of bit type havinghardfaced teeth Fluid cut teeth & cone Excessive circulation rate of fluid Excessive sand in circulating system Reduction in circulation fluid rate Removal of sand from circulation fluid Excessively undergauge Improper bit type Excessive rotating time Use of bit having greater gauge protection Reduce rotating hours Skidded due to balling Excessive WOB Improper bit type Insufficient fluid circulation rate Lighter WOB Use of softer formation bit type having teeth more widely spaced Increase fluid circulation rate ROLLER CONE BITSDrilling Problem Identification
Bits and Holemaking IPM Condition of Dull Bit Possible Cause Possible Remedies Polished diamonds Rotating in a hard formation without making hole Add WOB or select a bit with smaller diamonds/cutters Shattered diamonds Improper stabilisation Abnormal vibrations Improper handling Correct the stabilisation Reduce the vibration by changing the RPM Proper handling Sheared diamonds Improper break-in, Broken nose stones Clean bottom of hole, Correct break-in procedure Burned (flattened) diamonds Inadequate cooling Increase the circulation rate to improve cooling Burned bit Overheating as a result of plugging and/or balling up Take care of proper hydraulics Heat checking of PDC supports or bit body (matrix) Overheating Worn throat Fragments of hard formation rolling in the throat Proper hydraulics Loss of gauge Long intervals reamed with insufficient cooling due to clogged junk slots When reaming minimise RPM and bit weight Junk damage Junk in hole just ahead of the first diamond bit used Clean bottom on previous bit run with a junk basket in the string FIXED CUTTER BITS Drilling Problem Identification
Bits and Holemaking IPM 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 ROP • ROP is a function of WOB, RPM, mud properties and hydraulic efficiency
Bits and Holemaking IPM Cutting Structure Comparisons HP83EHP41H Faster Drilling Less Durable Slower Drilling More Durable 42
Tooth & Insert Cutter Designs Soft Formation • Fewer Teeth • Longer Teeth • Bigger Teeth • Sharper Teeth • Round Profile • Fracture-Resistant Tooth Material • Faster Drilling • Less Durable Hard Formation • More Teeth • Shorter Teeth • Smaller Teeth • Duller Teeth • Flat Profile • Wear-Resistant Tooth Material • Slower Drilling • More Durable 43
Bits and Holemaking IPM • Under no circumstances should the cutting structure of fixed cutter bit be allowed to contact any steel surfac • All bits should be gauged with an appropriately sized gauge ring • Bit serial number should be recorded, together with the bit type and diameter. • Tricone bits should be made up to the drill string using a correctly sized bit breaker. • Fixed cutter bits should be “walked” by hand before applying correct torque. • Natural diamond bits, impregnated bits and TSP bits have a fixed TFA which can not be modified at the rig si Bit Handling and Make up
Bits and Holemaking IPM Roller Cone Bits Running in • Make the bit up to proper torque. • Lower the bit slowly through ledges and dog legs • Lower the bit slowly at liner tops Roller cone bits are not designed for reaming. If reaming is required then it should be undertaken with light weight and low RPM • Protect nozzles from plugging Establish a bottom hole pattern • Rotate the bit and circulate when approaching bottom. This will prevent plugged nozzles and clear out hole fill. • Lightly tag the bottom with low RPM. • Gradually increase the RPM. • Gradually increase weight on WOB. Before re-running green bits • Make sure the bit is in gauge. • Check any bit for complete cutting structure. • Check any sealed bearing bit for effective seals. • Soak any sealed bearing bit in water or diesel to loosen formation packed in the reservoir cap equalisation ports. • Re-grease l4¾" diameter and larger open bearing bits. Bit Running Procedures
Bits and Holemaking IPM Fixed Cutter Bits PREPARATION • Before running a diamond bit into the hole, have a junk basket run on the previous bit. • After the previous bit is pulled, inspect it for junk damage and other wear, then gauge it. • If the previous bit appears OK, the bit may be prepared to be run into the hole. • Check O-ring and install nozzles, if appropriate, using the correct nozzle spanner as supplied by the bit manufacturer. • Check for cutter damage. • Check that the bit is within tolerance on diameter and that there is no foreign material inside it. Bit Running Procedures
Bits and Holemaking IPM Fixed Cutter Bits RUNNING THE BIT (ROTARY ASSEMBLY) • Handle the fixed cutter bit with care. DO NOT set the bit down without placing wood or a rubber pad beneath the diamond cutters. • A correct bit breaker should be used and the bit should be made up to the correct torque as determined by the pin connection size. • Care should be taken in running the bit through the rotary table and through any known tight spots. Hitting ledges or running through tight spots carelessly may damage the cutters or gauge. • Reaming is not recommended, however, if necessary, pick up the string and run the maximum fluid possible. Rotate at about 60 RPM. Advance bit through tight spot with no more than 4000 pounds weight on bit (WOB) at any time. • As hole bottom is approached, the last three joints should be washed down slowly at full flow and with 40 to 60 RPM to avoid plugging the bit with fill. • Once the bottom is located, the bit should be lifted just off bottom (0 to 1 foot if possible) and full volume circulated while slowly rotating for about 5 to 10 minutes. • After circulating, ease back to bottom and establish the bottom hole pattern. • When ready to start drilling, increase the rotary speed to about 100 RPM and start cutting a new bottom hole pattern with approx. 1000 to 4000 pounds WOB. • Cut at least one foot in this manner before determining optimum bit weight and RPM for drilling. • Determine optimum ROP by conducting a drill-off test. Bit Running Procedures
Bits and Holemaking IPM Fixed Cutter Bits RUNNING THE BIT (PDM or TURBINE) • Start the pumps and increase to the desired flow rate when approaching bottom. • After a short cleaning period, lower the bit to bottom and increase WOB slowly. • After establishing a bottom hole pattern, additional weight may be slowly added. • As weight is increased, pump pressure will increase, so the differential pressure and WOB must be kept within the recommended downhole motor specifications. • drillpipe should be slowly rotated to prevent differential sticking. • All other operating practices are as per standard practices. Bit Running Procedures

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Brocas IADC

  • 1.
    Bits and Holemaking IPM Bitsand Holemaking DRILLING PRACTICES
  • 2.
    Bits and Holemaking IPM IADCBit Classification
  • 3.
    Bits and Holemaking IPM IADCClassification – Roller Cone Ref: SPE 23937 The IADC Roller Bit Classification System 8-1/2” EHP 51 517G 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 Formations 3 Soft Formations w ith Low Compressive Strength and High Drillability 4 Soft to Medium Formations w ith Low Compressive Strength 5 Medium Hard Formations w ith High Compressive Strength 6 Hard Semi-Abrasive and Abrasive Formations 7 Extremely Hard and Abrasive Formations 8 INSERT BITS 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 Bearing 1 Roller Bearing Air Cooled 2 Roller Bearing Gauge Protected 3 Sealed Roller Bearing 4 Sealed Roller Brg - Gauge Protected 5 Sealed Friction Bearing 6 Sealed Frction Brg Gauge Protected 7 Features Available (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
  • 4.
    Bits and Holemaking IPM Soft Hard IADCCodes Tooth 2 1 3 1-1 1-3 2-1 IPM
  • 5.
  • 6.
  • 7.
  • 8.
  • 9.
    Bits and Holemaking IPM IADCBit Dull Grading Code
  • 10.
    Bits and Holemaking IPM IADCBit 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 that describes bit wear and the reason why the bit was pulled. INNER ROWS OUTER ROWS DULL CHAR LOCA- TION BRNG/ SEALS GAUGE 1/16” OTHER CHAR REASON PULLED Cutting Structure RemarksB G
  • 11.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 Inner Cutting Structure (All Inner Rows) Outer Cutting Structure (Gauge Row Only) 0 1 2 3 4 5 6 7 8 Cone 2 Cone 3 Cone 1 IPM Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 12.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 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 *BC - Broken Cone BF - Bond Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Fixed Cutter Bits Roller Cone Bits Note that this is for the Primary dull characteristics. Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 13.
    Bits and Holemaking IPM FixedCutter – Main Wear Characteristics NO WEAR (NO) WORN CUTTER (WT) BROKEN CUTTER (BT) LOST CUTTER (LT) EROSION (ER) POST OR STUD CUTTERS NO WEAR (NO) WORN CUTTER (WT) BROKEN CUTTER (BT) LOST CUTTER (LT) CYLINDER CUTTERS BOND FAILURE (BF) BOND FAILURE (BF) Courtesy of
  • 14.
    Bits and Holemaking IPM DullCharacteristics – 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 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 Fixed Cutter Bits BU - Balled Up Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 15.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples BT – Broken Teeth (primary) CD – Cone Dragged (secondary)Ref : IADC Drilling Manual – Eleventh Edition
  • 16.
    Bits and Holemaking IPM DullCharacteristics – 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 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 Fixed Cutter Bits CT – Chipped Cutter Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 17.
    Bits and Holemaking IPM DullCharacteristics – 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 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 Fixed Cutter Bits LT – Lost Cutter Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 18.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples BT – Broken Teeth/Cutters Ref : IADC Drilling Manual – Eleventh Edition
  • 19.
    Bits and Holemaking IPM DullCharacteristics – 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 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 Fixed Cutter Bits La RO – Ring Out Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 20.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples JD – Junk Damage Ref : IADC Drilling Manual – Eleventh Edition
  • 21.
    Bits and Holemaking IPM DullCharacteristics – 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 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 Fixed Cutter Bits WT – Worn Cutters Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 22.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples SD - Shirttail Damage Ref : IADC Drilling Manual – Eleventh Edition
  • 23.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples TR - Tracking
  • 24.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples SS – Self Sharpening Wear Ref : IADC Drilling Manual – Eleventh Edition
  • 25.
    Bits and Holemaking IPM *BC- Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Roller Cone Bits Dull Characteristics – Some Examples ER – Erosion Ref : IADC Drilling Manual – Eleventh Edition
  • 26.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS DULL CHAR LOCA- TION BRNG/ SEALS GAUGE 1/16” OTHER CHAR REASON PULLED Cutting Structure RemarksB G    Fixed Cutter Bits Roller Cone Bits C - Cone N - Nose T - Taper S - Shoulder G - Gauge N - Nose Row M - Middle Row G - Gauge Row A - All Rows Cone 1, 2 or 3 Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 27.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 used, 8 - All life used, i.e., no bearing life remaining.) Non Sealed Bearings Sealed Bearings E - Seals Effective F - Seals Failed N - Not Able to Grade Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 28.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 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
  • 29.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 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  *BC - Broken Cone BF - Bone Failure BT - Broken Teeth/Cutters BU - Balled Up Bit *CC - Cracked Cone *CD - Cone Dragged CI - Cone Interference CR - Cored CT - Chipped Teeth/Cutters ER - Erosion FC - Flat Crested Wear HC - Heat Checking JD - Junk Damage *LC - Lost Cone LN - Lost Nozzle LT - Lost Teeth/Cutters OC - Off-Center Wear PB - Pinched Bit PN - Plugged Nozzle/Flow Passage RG - Rounded Gauge RO - Ring Out SD - Shirttail Damage SS - Self Sharpening Wear TR - Tracking WO - Washed Out Bit WT - Worn Teeth/Cutters NO - No Dull Characteristic * Show Cone under Location 4 Fixed Cutter Bits Roller Cone Bits This is for the Secondary dull char. and it uses the same codes as for the Primary dull char. Ref : Reed Hycalog PDC & Roller Cone Product Technology Reference Information
  • 30.
    Bits and Holemaking IPM IADCBit Dull Grading Code INNER ROWS OUTER ROWS 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 DST - Drill Stem Test DTF - Down hole Tool Failure RIG - Rig Repair CM - Condition Mud CP - Core Point DP - Drill Plug FM - Formation Change HP - Hole Problems HR - Hours 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
  • 31.
    Bits and Holemaking IPM Keyto Dull Bit Grading: Grade a Lot of Dulls ! Photo courtesy of
  • 32.
    Bits and Holemaking IPM BITRECORD Well : BIT RECORD Date : Bit Data BHA Bit Size Bit type Serial IADC Nozzles Depth Depth Drilling ROP Bit krevs WOB Rot Flow Press Inc Mud Total Total Total Dull 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 115 3 x 18, 1 x 16 15 420 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 Run Data Bit life Grading To be filled up at wellsite •BHA nb does not always = bit nb •Drilling time = bit time on bottom (← Mud loggers) •Krevs = 1000 bit revolution (← Mud loggers)
  • 33.
    Bits and Holemaking IPM DrillingParameters vs Bit Performance
  • 34.
    Bits and Holemaking IPM DIFFERENTIALPRESSURE AT BIT Erosion Depth of Cut Wash out Worn CuttersWOB Flow Rate Drilling Problem Identification
  • 35.
    Bits and Holemaking IPM CIRCULATINGPRESSURE (standpipe pressure with bit off bottom) Nozzles Restriction Wash out PumpsMud Weight Flow Rate Mud Properties Air in Mud Drilling Problem Identification
  • 36.
    Bits and Holemaking IPM TORQUE WOB HoleAngle Wash out FormationMud Weight Hole Cleaning Mud Properties Junk Bit Related RPM Reaming Dry Drilling Drilling Problem Identification
  • 37.
    Bits and Holemaking IPM RATEOF PENETRATION RPM/WOB Hole Angle Wash out FormationOverbalance Hydraulics Bit RelatedJunk Drilling Problem Identification
  • 38.
    Bits and Holemaking IPM Conditionof Dull Bit Possible Causes Possible Remedies Excessive bearing wear Excessive rotary speed Excessive rotating time Excessive WOB Excessive sand in circulating system Un-stabilised drill collars Improper bit type Slower rotary speed Reduced rotating hours Lighter WOB Removal of sand from circulating fluid Stabilise drill collars Use harder formation bit type with stronger bearing structure Excessive broken teeth Improper bit type Improper break-in procedure used for new bit Excessive WOB for type used Use harder formation bit type having more teeth Proper break-in procedure used for new bit Lighter WOB Unbalanced tooth wear Improper bit type Improper break-in procedure used for new bit Use of different bit type based upon the rows of teeth which are excessively worn on the dull bit Proper break-in procedure used for new bit Excessive tooth wear Excessive rotary speed Improper bit type Use of nonhardfaced type Slower rotary speed Use of harder formation bit type having a greater number of teeth Use of bit type havinghardfaced teeth Fluid cut teeth & cone Excessive circulation rate of fluid Excessive sand in circulating system Reduction in circulation fluid rate Removal of sand from circulation fluid Excessively undergauge Improper bit type Excessive rotating time Use of bit having greater gauge protection Reduce rotating hours Skidded due to balling Excessive WOB Improper bit type Insufficient fluid circulation rate Lighter WOB Use of softer formation bit type having teeth more widely spaced Increase fluid circulation rate ROLLER CONE BITSDrilling Problem Identification
  • 39.
    Bits and Holemaking IPM Conditionof Dull Bit Possible Cause Possible Remedies Polished diamonds Rotating in a hard formation without making hole Add WOB or select a bit with smaller diamonds/cutters Shattered diamonds Improper stabilisation Abnormal vibrations Improper handling Correct the stabilisation Reduce the vibration by changing the RPM Proper handling Sheared diamonds Improper break-in, Broken nose stones Clean bottom of hole, Correct break-in procedure Burned (flattened) diamonds Inadequate cooling Increase the circulation rate to improve cooling Burned bit Overheating as a result of plugging and/or balling up Take care of proper hydraulics Heat checking of PDC supports or bit body (matrix) Overheating Worn throat Fragments of hard formation rolling in the throat Proper hydraulics Loss of gauge Long intervals reamed with insufficient cooling due to clogged junk slots When reaming minimise RPM and bit weight Junk damage Junk in hole just ahead of the first diamond bit used Clean bottom on previous bit run with a junk basket in the string FIXED CUTTER BITS Drilling Problem Identification
  • 40.
    Bits and Holemaking IPM Bitperformance • Main function: ROP and longevity • Drilling fluid is circulated through passageways in the bit to remove cuttings and apply hydraulic power to improve ROP • ROP is a function of WOB, RPM, mud properties and hydraulic efficiency
  • 41.
    Bits and Holemaking IPM CuttingStructure Comparisons HP83EHP41H Faster Drilling Less Durable Slower Drilling More Durable 42
  • 42.
    Tooth & InsertCutter Designs Soft Formation • Fewer Teeth • Longer Teeth • Bigger Teeth • Sharper Teeth • Round Profile • Fracture-Resistant Tooth Material • Faster Drilling • Less Durable Hard Formation • More Teeth • Shorter Teeth • Smaller Teeth • Duller Teeth • Flat Profile • Wear-Resistant Tooth Material • Slower Drilling • More Durable 43
  • 43.
    Bits and Holemaking IPM •Under no circumstances should the cutting structure of fixed cutter bit be allowed to contact any steel surfac • All bits should be gauged with an appropriately sized gauge ring • Bit serial number should be recorded, together with the bit type and diameter. • Tricone bits should be made up to the drill string using a correctly sized bit breaker. • Fixed cutter bits should be “walked” by hand before applying correct torque. • Natural diamond bits, impregnated bits and TSP bits have a fixed TFA which can not be modified at the rig si Bit Handling and Make up
  • 44.
    Bits and Holemaking IPM RollerCone Bits Running in • Make the bit up to proper torque. • Lower the bit slowly through ledges and dog legs • Lower the bit slowly at liner tops Roller cone bits are not designed for reaming. If reaming is required then it should be undertaken with light weight and low RPM • Protect nozzles from plugging Establish a bottom hole pattern • Rotate the bit and circulate when approaching bottom. This will prevent plugged nozzles and clear out hole fill. • Lightly tag the bottom with low RPM. • Gradually increase the RPM. • Gradually increase weight on WOB. Before re-running green bits • Make sure the bit is in gauge. • Check any bit for complete cutting structure. • Check any sealed bearing bit for effective seals. • Soak any sealed bearing bit in water or diesel to loosen formation packed in the reservoir cap equalisation ports. • Re-grease l4¾" diameter and larger open bearing bits. Bit Running Procedures
  • 45.
    Bits and Holemaking IPM FixedCutter Bits PREPARATION • Before running a diamond bit into the hole, have a junk basket run on the previous bit. • After the previous bit is pulled, inspect it for junk damage and other wear, then gauge it. • If the previous bit appears OK, the bit may be prepared to be run into the hole. • Check O-ring and install nozzles, if appropriate, using the correct nozzle spanner as supplied by the bit manufacturer. • Check for cutter damage. • Check that the bit is within tolerance on diameter and that there is no foreign material inside it. Bit Running Procedures
  • 46.
    Bits and Holemaking IPM FixedCutter Bits RUNNING THE BIT (ROTARY ASSEMBLY) • Handle the fixed cutter bit with care. DO NOT set the bit down without placing wood or a rubber pad beneath the diamond cutters. • A correct bit breaker should be used and the bit should be made up to the correct torque as determined by the pin connection size. • Care should be taken in running the bit through the rotary table and through any known tight spots. Hitting ledges or running through tight spots carelessly may damage the cutters or gauge. • Reaming is not recommended, however, if necessary, pick up the string and run the maximum fluid possible. Rotate at about 60 RPM. Advance bit through tight spot with no more than 4000 pounds weight on bit (WOB) at any time. • As hole bottom is approached, the last three joints should be washed down slowly at full flow and with 40 to 60 RPM to avoid plugging the bit with fill. • Once the bottom is located, the bit should be lifted just off bottom (0 to 1 foot if possible) and full volume circulated while slowly rotating for about 5 to 10 minutes. • After circulating, ease back to bottom and establish the bottom hole pattern. • When ready to start drilling, increase the rotary speed to about 100 RPM and start cutting a new bottom hole pattern with approx. 1000 to 4000 pounds WOB. • Cut at least one foot in this manner before determining optimum bit weight and RPM for drilling. • Determine optimum ROP by conducting a drill-off test. Bit Running Procedures
  • 47.
    Bits and Holemaking IPM FixedCutter Bits RUNNING THE BIT (PDM or TURBINE) • Start the pumps and increase to the desired flow rate when approaching bottom. • After a short cleaning period, lower the bit to bottom and increase WOB slowly. • After establishing a bottom hole pattern, additional weight may be slowly added. • As weight is increased, pump pressure will increase, so the differential pressure and WOB must be kept within the recommended downhole motor specifications. • drillpipe should be slowly rotated to prevent differential sticking. • All other operating practices are as per standard practices. Bit Running Procedures

Editor's Notes

  • #2 <number> Break the ice with the students by asking them how the course has been so far. Mention that they should feel free to interrupt at any time that they wish to ask a question or comment on the topic being discussed.
  • #3 <number>
  • #4 Highlights of System: Four character system Modeled after the Roller Cone system. Describes a bits appearance. Different meaning for PDC than Nat. Dia. / TSD bits. Gives a relative toughness of application for a design. Bits within a code may drill a wide variety of formations. First Character - Body Material n M - Matrix Body n S - Steel Body 2nd Character - PDC - Cutter Density TSP/ND - Size n For PDC’s this designates the general formation hardness a bit is designed to drill. n It is designated by a number . n 1- 4 are assigned to describe PDC bits and is designed to indicate the toughness of formation for which designed. n 6-8 are assigned to describe Natural Diamond or TSP bits and represents the cutter size. Third Character - Size / Type n For PDC bits this character represents the cutter size broken down in three groups. u 1 = > 24mm u 2 = 14 - 24mm u 3 = < 14mm n For Nat. Dia. / TSP bits it represents the cutting element. u 1 = Nat. Dia. u 2 = TSP u 3 = Combination u 4 = Impregnated Fourth Character - Body Style (profile) n Same for both bit types. n Breaks down into four basic Styles. u 1 - Flat or Fishtail u 2 - Short u 3 - Medium u 4 - Long n Borderline bits can fall into either category.
  • #5 Highlights of System: Four character system Modeled after the Roller Cone system. Describes a bits appearance. Different meaning for PDC than Nat. Dia. / TSD bits. Gives a relative toughness of application for a design. Bits within a code may drill a wide variety of formations.
  • #6 <number>
  • #7 <number>
  • #8 <number>
  • #9 <number>
  • #10 <number>
  • #11 <number>
  • #12 Consistency in bit grading is crucial to the engineer’s ability to analyse bit performance and to improve bit selection. The IADC method has been adopted worldwide and serves as a reference. Let’s do a quick refresher from the IDPT and look at the 8 characters individually:
  • #13 This shows how the cutting structure is graded for both PDC and roller cone bits. You may often hear drillers referring to hardly used bits as “green” bits or as “one-one”, meaning that the cutting structure of all rows was almost intact.
  • #14 The dull characteristics is to provide further details on the type of wear present on the used bit. A different set exist for PDC and roller cone bits although some of the codes are the same. We’re going to have a look at pictures that describe a few of these characteristics. Ask the students to describe each one before showing the answer.
  • #15 This diagram shows the differences between the main wear characteristics for fixed cutter bits. Take the time to go through each to explain the differences.
  • #16 The main causes of bit balling are sticky formations and poor hydraulics.
  • #17 A roller cone balled up bit may show tooth wear due to cone dragging or skidding (one or more cones are not turning because of formation being packed between the cones). Note that balling cause the cones to drag which is why it becomes the main characteristics while cone dragged is secondary. The same would apply if erosion has caused inserts to fall off. The primary dull characteristics would be ER for Erosion and the secondary would be LT for Lost Teeth.
  • #18 Possible cause for chipped cutter is vibration.
  • #19 Possible causes for lost cutter are: - manufacturing defect - bit whirl - vibration
  • #20 Self Explanatory
  • #21 Ring out is typically due to the presence of relatively large junk in the hole. It is most likely from the bit itself but it could also be from junk that fell in the hole (e.g. tong die). Possible causes for the bit loosing a large chunk of steel are: - Type of formation being drilled - Incorrect Operating Parameters (WOB, RPM, Flow) - Excessive Bit Hydraulics / Mud properties - Vibration
  • #22 Junk damage can be detected by marks on any part of the bit.
  • #23 This shows uniform wear across the cutters.
  • #24 Shirttail damage is not a cutting structure dulling characteristics. Excessive shirttail damage may lead to bearing seal failure.
  • #25 Tracking happens when the teeth mesh like a gear in the bottom hole pattern. Cone shell wear is typically apparent between the cutters in a row.
  • #26 In this case, the cutters wear in a manner such that they retain a sharp crest shape .
  • #27 Erosion leads to a reduction or loss of cone shell material. This can in turn lead to a loss of inserts. The main causes of erosion are: - abrasive formation wear due to tracking - excessive hydraulics resulting in high velocity fluid erosion - abrasive drilling fluids or poor solids control
  • #28 This is to indicate the location, on the bit, where the wear is mostly present.
  • #29 This is one of the most subjective criteria. Wellsite supervisors typically look for slack in the bearing to estimate the remaining life. Hours on the bit are also used to estimate remaining bearing life.
  • #30 Self Explanatory
  • #31 It is in this category that we would indicate things that are not a cutting structure dulling characteristics such as shirttail damage, washed out bit, etc..
  • #32 Self Explanatory
  • #33 Self Explanatory
  • #35 <number>
  • #36 <number> Reduced differential pressure indicates one or more of the following: Reduced flow rate Wash out in the pipe Extreme erosion of the bit (not usual) Reduced WOB An increase in differential pressure indicates one or more of the following: Increased flow rate Cutters have worn so that the bit face is in contact with the bottom of the hole. Excessive WOB Large depth of cut: formation softer than expected
  • #37 <number> Increased circulating pressure could be due to one or more of the following: Heavier mud weight or inadequate mud properties Plugged or partially plugged bit nozzles Increased flow rate Annular restriction Decreased circulating pressure could be due to one or more of the following: Lighter mud weight Wash out Reduced flow rate Air in the mud Pump malfunction
  • #38 <number> Increasing torque: Hole angle changing, Wash out, Formation change, Poor mud properties, WOB increased, Poor hole cleaning and Bearing failure on tri-cone bit. Decreasing torque: Formation change, Rotary speed change, WOB decreased, Improvement in mud properties, and Hole angle straightening out. Irregular/Varying torque: Reaming with stabiliser, Dry drilling, Bit balled-up, Drilling Sand formation, Junk in hole, Wash out, Excessive WOB and Rotary speed change.
  • #39 <number> An increase in ROP may indicate: Formation change and/or Drilling close to balance (overbalance reducing) A decrease in ROP may result from one or more of the following:: Worn bit WOB, RPM or hydraulics not optimised Formation change Crooked hole Wash out Overbalance increasing Varying ROP indicates one or more of the following: Formation layers Bit wearing out Bit balled-up Wash out Inconsistent transference of WOB
  • #40 <number>
  • #41 <number>
  • #45 <number> Care should be exercised when handling tricone bits fitted with tungsten carbide inserts and fixed cutter bits of all types. Under no circumstances should the cutting structure of fixed cutter bit be allowed to contact any steel surfaces on the rig. Prior to initial make-up, all bits should be gauged with an appropriately sized gauge ring i.e. calibrated “Go” and “No Go” gauge rings. Because roller cone bits and diamond bits are manufactured to different tolerances, it is important that bits be graded using the appropriate gauge ring. A 'Go' gauge, designed for grading roller cone bits, will show an in gauge fixed cutter bit to be undergauge. A 'No Go' gauge should always be used to grade a fixed cutter bit. The bit serial number should be recorded, together with the bit type and diameter. The bit should be closely examined for damage, blocked nozzles, etc. If needed, TFA (Total Flow Area) can then be modified using the appropriate spanner to change the nozzles. In all cases, check that nozzles are properly fitted. Natural diamond bits, impregnated bits and TSP bits have a fixed TFA which can not be modified at the rig site. Tricone bits should be made up to the drill string using a correctly sized bit breaker. Fixed cutter bits should be “walked” by hand onto the bit sub until the tool joints shoulder. The correct make–up torque should then to be applied.
  • #46 <number>
  • #47 <number>
  • #48 <number>
  • #49 <number>