Table of ContentsIntroduction: Basic Well Completion Concepts ..................................................... 1-1

Porosity ....................................................................................................... 1-1

Saturation ................................................................................................... 1-2

Permeability ................................................................................................ 1-2Relative Permeability .................................................................................. 1-2Natural Fractures ........................................................................................ 1-3Reservoir Pressure ..................................................................................... 1-3

Pressures ................................................................................................... 1-4Pressure Differential ................................................................................... 1-5Well Temperature ....................................................................................... 1-5Fluid Properties .......................................................................................... i-6

High Temperature and High Pressure Wells .............................................. 1-6Introduction: Geology ................................................................................................. 11-1Formation Sequences and Layering .......................................................... 11-4Well Planning ............................................................................................................... 111-1Drilling the Pay, Selecting the Interval and the Initial Design .......................... 1-1Coiled Tubing Drilling ....................................................................................... 1-6Underbalanced Drilling .................................................................................... 1-6

Slimholes ......................................................................................................... 1-7Initial Completion Design

............................................................................... 1-7Selecting the Pay Zone .................................................................................... 1-7References - Drilling

.................................................................................... 1-12Other References

......................................................................................... 1-12Casing Design .............................................................................................................. 2-1Open Hole Completions ........................................................................... 2-1Cased Hole Completions .......................................................................... 2-1Description of Casing Strings ................................................................... 2-2Casing Clearance ..................................................................................... 2-3Connections .............................................................................................. 2-5Casing Weights and Grades ..................................................................... 2-6Casing Design Safety Factors .................................................................. 2-7Load Description ....................................................................................... 2-7Casing String Design ..................................................................................... 2-14API Equations ......................................................................................... 2-14Buoyancy ................................................................................................ 2-16

Example 2.1 ............................................................................................ 2-17Collapse Design - Non-API Method ........................................................ 2-18Example 2.2 - Single String Casing Design ............................................ 2-22Example 2.3 - Casing Design - Intermediate String ................................ 2-26Design a 9-5/8"In termediate String

........................................................ 2-26Final Design ............................................................................................ 2-30High Pressure Gas ................................................................................. 2-30Additional Graphical Illustrations ............................................................ 2-30Running The Casing ............................................................................... 2-30Casing String Design - Deviated Wells

.......................................................... 2-34Liner Design ................................................................................................... 2-36Example 2.4 - Liner Design .................................................................... 2-36Liner Tie-Backs .............................................................................................. 2-38Cementing ..................................................................................................... 2-39...- 1 -

Problems ........................................................................................................ 2-42

References .................................................................................................. 2-42

Other References ........................................................................................ 2-45Casing Horizontal Wells ................................................................................. 2-54Reach Interval ......................................................................................... 2-54Rotation and Torque ................................................................................ 2-55The Build Interval .................................................................................... 2-55Bending Stress ........................................................................................ 2-56Vertical Interval ........................................................................................ 2-57

Application ............................................................................................... 2-58

Cementing ...................................................................................................................... 3-1Cement Density ......................................................................................... 3-4Factors Affecting Cement .......................................................................... 3-5Cementing Design ............................................................................................ 3-6Primary Cementing ........................................................................................... 3-6Cementing Calculations .......................................................................... 3.14Balanced Plug Setting ............................................................................. 3.15Squeeze Cementing ................................................................................ 3-16Cement Squeeze Tools ........................................................................... 3-17Liner Cementing ...................................................................................... 3-18Frictional Pressure Dropin Pipe ............................................................... 3-19

References .................................................................................................. 3-20Cementing: Review Questions .................................................................... 3-23Packer Selection and Tubing Forces ...................................................................... 4.1Production Packers ................................................................................... 4. 1Special Equipment .................................................................................... 4. 1Dressing Packers ...................................................................................... 4-3Allowing Tubing Movement ....................................................................... 4-3Effects of Temperature .............................................................................. 4-4Deep Completions ..................................................................................... 4-5Seal Considerations .................................................................................. 4-8Seal Problems ........................................................................................... 4.9Tubing and Packer Forces ........................................................................ 4-9Length or Force Changes? ...................................................................... 4-13Setting the Packer ................................................................................... 4-14Combined Forces .................................................................................... 4-16Special Packers .............................................................................................. 4-17Tubing Stretch and Compression ............................................................ 4-17

Problems ........................................................................................................ 4-17

References .................................................................................................. 4-18

Well Heads, Chokes and SSSVs ............................................................................... 5-1Well heads ........................................................................................................ 5-1Subsea Well heads ............................................................................................ 5-3Coiled Tubing Well Heads ................................................................................ 5-5Hydrate Control in Coiled Tubing Completions ................................................ 5-5

Chokes ............................................................................................................. 5-7Subsurface Safety Valves ................................................................................ 5-8Fluid Loss .................................................................................................. 3-4Application ................................................................................................. 3.7

References ................................................................................................... 5-1 2Corrosion and Erosion ............................................................................................... 6-1Corrosion ......................................................................................................... 6-1The Corrosion Circuit ................................................................................ 6-2Chemical Reaction ................................................................................... 6-2Acid Gases ............................................................................................... 6-4Controlling Corrosion ................................................................................ 6-5Materials for Sour Service ...................................................................... 6-1 0

CO2 Corrosion ........................................................................................ 6-1 1Other Factors ........................................................................................... 6-1 2Corrosion by Stimulation Acids ............................................................... 6-1 3Destruction of Elastomers ...................................................................... 6-1 4Microbial Corrosion ................................................................................. 6-1 4Nonmetallic Tubulars .............................................................................. 6-1 4

Predictive Techniques and Inspection Devices ...................................... 6-1 4Erosion ........................................................................................................... 6-1 5Corrosion References

.................................................................................. 6-1 7Inflow Performance, Tubing Selection, and Artificial Lift .................................. 7-1Inflow Performance ................................................................................... 7-1Tubing Design .......................................................................................... 7-2

Heading .................................................................................................... 7-8Tubing Design .........................................................................................7. -9Artificial Lift ............................................................................................... 7-9Rod Pump ............................................................................................... 7-1 0Rod Pump ............................................................................................... 7-1 2

Gas Lift ................................................................................................... 7-1 6Electrical Submersible Pump .................................................................. 7-1 6Other Systems ........................................................................................ 7-1 6Lift Selection ........................................................................................... 7-1 6Reservoir Fluid Classification ................................................................. 7-1 7

References ................................................................................................... 7-1 9Special Completions (Deviated, Thermal Multiples, and Multi-Laterals) ....... 8-1Deviated Completions ...................................................................................... 8-1

Descriptions .............................................................................................. 8- 1Horizontal Well Candidate Selection ............................................................... 8-2Horizontal Completions Background ............................................................... 8-3Path of the Horizontal Section ......................................................................... 8-7Artificial Lift Options ......................................................................................... 8-8Solids Control Techniques ............................................................................... 8-9

Fracturing ............................................................................................... 8-1 0Increasing Reservoir Contact ........................................................................ 8-12

Logging ................................................................................................... 8-1 3Wellbore Stability .................................................................................... 8-1 5

Perforating .............................................................................................. 8-1 7

CorrosionErosion ................................................................................... 8-1 8Gravel Packs .......................................................................................... 8-1 9Coning Control ........................................................................................ 8-1 9Heading Problems ......................................................................................... 8-21Multi-lateral Completions ............................................................................... 8-21Lateral Technology Levels ...................................................................... 8.22Candidate List ................................................................................................. 8.24The candidate list for design is still forming but has the following considerations:8-24Thermal Completions ..................................................................................... 8.25Steam Projects ........................................................................................ 8-25Combustion Projects ............................................................................... 8-26Alternate Heating Methods ...................................................................... 8.26Stimulation ............................................................................................... 8.26Corrosion and Scale ................................................................................ 8-27Insulation ................................................................................................. 8-28Tubular Design ........................................................................................ 8-28Cementing Considerations ...................................................................... 8.30Completions ............................................................................................ 8.3 1

Coalbed Methane Wells ................................................................................. 8-32Multiple Completions ...................................................................................... 8-35Tubingless Completions .......................................................................... 8.36Selection of a Completion ....................................................................... 8-38Monobores .............................................................................................. 8-38Coiled Tubing Completions ............................................................................ 8-40References .................................................................................................. 8-42Logging ........................................................................................................... 8-50Productivity Estimates .................................................................................... 8.53Perforating ..................................................................................................................... 9.1Temperature Effect .................................................................................... 9-6Perforation Size ......................................................................................... 9-6Calculated Pressure Drop ....................................................................... 9-16Partial Completion ................................................................................... 9-16Underbalance Perforating ....................................................................... 9-17Tubing Conveyed Perforating .................................................................. 9-19Wireline Perforating ................................................................................. 9-21Highly Deviated Wells ............................................................................. 9-22Depth Control .......................................................................................... 9.22

Cement Damage ..................................................................................... 9.23Casing Damage ....................................................................................... 9-23Stress in an Deviated Well ............................................................................. 8-50Well Completion Problems ............................................................................. 8-52Extreme Overbalance Perforating ........................................................... 9-19Repetiora ting Considerations .................................................................. 9-24Stimulation Considerations ...................................................................... 9-25Stimulations in Deviated Wells - Effect of Perfs ...................................... 9-26A brasiveErosive Perforating ................................................................... 9-26Pipe Cutoff Methods ....................................................................................... 9-27Questions ................................................................................................ 9-27References - Perforating .............................................................................. 9-28

Formation Damage - Causes and Preventions ................................................... 10-1Clays ............................................................................................................... 10-6Common Types of Clay ........................................................................... 10-8Water lmbibition of Clays ........................................................................ 10-9. iv .Clay Swelling .......................................................................................... 10-9Clay Dispersion ...................................................................................... 10-9

Other Clay Problems ............................................................................ 10-1 0Paraffins and Asphaltenes ........................................................................... 10-1 1Emulsions .................................................................................................... 10-1 3Dispersions .................................................................................................. 10-1 5

Foams .......................................................................................................... 10-1 6

Froth ............................................................................................................ 10-1 6Wettability Problems .................................................................................... 10-1 6

Hydrates ...................................................................................................... 10-1 7

Scales .......................................................................................................... 10-1 8

Calcite ................................................................................................... 10-1 8Calcium Sulfate .................................................................................... 10-1 9Barium Sulfate ...................................................................................... 1 0-21Strontium Sulfate .................................................................................. 1 0-2 1Other Scales ......................................................................................... 10-22Particulate Damage ..................................................................................... 10-22Drilling Mud ........................................................................................... 10-22Cements ............................................................................................... 10-22

Kill Fluids .............................................................................................. 10-22Dirty Water ............................................................................................ 10-22Bacteria Problems ................................................................................ 1 0-22Effects of Formation Damage on Production ............................................... 10-23Rate and Skin ....................................................................................... 10-23Example 70.7 ........................................................................................ 1 0-23Example 70.2 ........................................................................................ 1 0-27Example 70.3 ........................................................................................ 1 0-28Using Production History Curves to Assess Damage .................................. 10-28Example 70.4 ........................................................................................ 10-28Workover Candidate Selection .................................................................... 10-29Example 70.5 ........................................................................................ 1 0-29Formation Damage - Questions

................................................................... 10-30

References ................................................................................................. 1 0-30Formation and Damage Diagnosis ........................................................................ 11-1Drill Stem Test (DST) ................................................................................... 11-1

Nodal Analysis ............................................................................................... 11-4Inflow Performance ...................................................................................... 11-5Equations of Flow ................................................................................... 11-9Decline Curves ............................................................................................ 1 1-1 5System Pressures ........................................................................................ 1 1-1 6Fluid Analysis ............................................................................................. 1 1-1 8Transient Tests .......................................................................................... 1 1-21Reservoir Logging Methods ....................................................................... 1 1-28Gamma Ray Logging ............................................................................ 1 1-28Acoustic or Sonic Logging .................................................................... 1 1-28Neutron Logging ................................................................................... 1 1-29Density Logging .................................................................................... 1 1 -29Natural Gamma Ray Spectroscopy Log ............................................... 1 1-30-VInducedGamma Ray Spectroscopy Log ............................................... 1 1-30Depth of lnvasion .................................................................................. 1 1-35Other Logs ............................................................................................. 1 1-36

Cased Hole Logging .............................................................................. 1 1-37Electric Logging Tool Response ................................................................ 1 1-38Direct Borehole Investigation ................................................................ 1 1-40Formation Tester ................................................................................... 1 1-41Fluid Movement Surveys .............................................................................. 1 1-42Fluid Surveys - Formation

............................................................................ 1 1-43Fluid Surveys - Wellbore .............................................................................. 1 1-43Mapping ..................................................................................................... 1 1-47Rock Mechanics Information From Logs ................................................... 1 1-51Basic Logging Tool Response ................................................................... 11 -55Gamma Ray Logging ................................................................................. '1 1-56Neutron Logging ........................................................................................ 1 1-56Density Logging ......................................................................................... 1 1-57Natural Gamma Ray Spectroscopy Log .................................................... 1 1-57Induced Gamma Ray Spectroscopy Log ................................................... 11-57

References ................................................................................................ 1 1-58Chemical and Thermal Stimulation ........................................................................ 12-1

Example 12.1 .......................................................................................... 12-2Example 12.2 .......................................................................................... 12-2Selecting a Candidate Well ............................................................................ 12-3Evaluation of Stimulations

.............................................................................. 12-3Selective Stimulation ...................................................................................... 12-4Diverting vs . Fluid Loss Control .............................................................. .l 2-4Candidates .............................................................................................. 12-4Diverter Operation ................................................................................... 12-5Limited Entry (Pressure Differential Diverting) ....................................... .1 2-5Mechanical Diverting ............................................................................... 12-6Chemical Diverlers ................................................................................ 12-1 1lnterface Treatments ............................................................................. 12-1 4Diverler/Fluid Loss Control Stages ........................................................ 12-1 5HCVHF Treatment Diversion ................................................................. 12-1 7Recommendations ................................................................................ 1 2-1 7Packoff Techniques ............................................................................... 12-1 8Technology of Bridging .......................................................................... 12-1 8Depth of Diversion ................................................................................. 12-1 8Chemical Stimulation Techniques ................................................................ 12-1 9

Acidizing ................................................................................................ 12-1 9Open-Hole Logging ............................................................................... 1 1-30Noise Logging ....................................................................................... 1 1 -46Borehole Surveys .................................................................................. 1 1-47Completion and Lift Analysis ..................................................................... 1 1-50Production and Operations Information ..................................................... 1 1-50Mechanical Properties ........................................................................... 1 1-53Acoustic or Sonic Logging ......................................................................... 1 1-56Cleanup ................................................................................................. 12-1 8HF Acid Spending Rates .............................................................................. 12-20-viSolvents....................................................................................................... 12-21

Gases .......................................................................................................... 12-22

Surfactants ................................................................................................... 12-22

Reactants ..................................................................................................... 12-22Treatment Types .......................................................................................... 12-22Damage Removal ........................................................................................ 12-23Reaction Rate Factors ................................................................................. 12-24

Temperature ......................................................................................... 12-24

Pressure ............................................................................................... 1 2-24Area Volume Ratio ............................................................................... 12-24Acid Concentration ............................................................................... 1 2-24Acid Selection ....................................................................................... 12-24Formation Composition ........................................................................ 1 2-25Additives ...................................................................................................... 12-25Surfactants ........................................................................................... 12-25

Weffability ............................................................................................. 12-26Mutual Solvents .................................................................................... 1 2-27Wash Design ............................................................................................... 12-28Wellbore Cleanup and Acid Wash ........................................................ 12-28Solvent Wash of Injection Wells ........................................................... 12-28Perforation Breakdown ......................................................................... 1 2-28Extreme Overbalance Perforating ............................................................... 12-29Matrix Acidizing Design ............................................................................... 12-29Obtaining the Required Information ...................................................... 1 2-29Designing the Treatment ...................................................................... 1 2-3 1Thermal Stimulation ..................................................................................... 12-35Chemical Heat Generation ................................................................... 1 2-37

References ................................................................................................. 12-38Granular Salt ........................................................................................ 12-43100-Mesh Sand .................................................................................... 12-43Calcium Carbonate ............................................................................... 1 2-43

Naphthalene ......................................................................................... 12-43Benzoic Acid Flakes ............................................................................. 12-44Wax Beads ........................................................................................... 12-44Organic Resin Beads ............................................................................ 12-44Organic Resin Dispersions ................................................................... 1 2-44Micron Size Patticulates ....................................................................... 1 2-44

Poiymers ............................................................................................... 12-45

Others ................................................................................................... 12-45

Fracturing .................................................................................................................... 13-1Recovery by Fracturing .................................................................................. 13-1Fracturing Economics .................................................................................... 13-2Fracturing Length and Conductivity Decisions .............................................. 13-3Fracture Design ........................................................................................... 13-1 5Fracture Length and Width - Modeling ................................................. 13-1 5Fracture Orientation and Formation Stresses ....................................... 1 3-1 6

Fluid Loss ............................................................................................. 1 3-1 7Fracturing Design ................................................................................. 1 3-20Closure Stress ....................................................................................... 13-25Fracture Treatments .............................................................................. 13-29Fracture Treatment Design ................................................................... 13-29When To Fracture ................................................................................. 13-33Treatment Pressure Behavior ............................................................... 1 3-33

References ................................................................................................ 13-34Unstable Formations and Sand Control ............................................................... 14-1Sand Cementation .......................................................................................... 14-1Formation Characterization ..................................................................... 14-2Sand Movement Prediction ..................................................................... 14-4Sand Control Considerations ................................................................ 1 4-1 2Sand Control ......................................................................................... 14-1 3Alternate Gravel Sizing Methods ........................................................... 1 4-20Mobility of Fines .................................................................................... 14-22Sand Sorting Considerations ................................................................. 1 4-23Benefits of Larger Gravel ...................................................................... 14-24Carrier Fluids ......................................................................................... 14-26

Equipment ............................................................................................. 1 4-28Packing Methods ................................................................................... 14-29Fluid Loss Control ................................................................................. 14-30Alternate Path Gravel Packing .............................................................. 14-30

Pressure Drops Across Gravel Packs ................................................... 14-31

Example ................................................................................................ 14-32Pack and Frac Technology .................................................................... 1 4-32

Reservoir Lamination and Well Deviation ............................................. 14-33Other Unstable Formations ................................................................... 1 4-33

References - Gravel Pack

.......................................................................... 14-34Workovers and Fluids ............................................................................................... 15-1Well Control ............................................................................................. 15-1Example 15 . I .......................................................................................... 15-2Example 15.2 .......................................................................................... 15-3Example 15.3 .......................................................................................... 15-3Shut-In ..................................................................................................... 15-5(Re)Gaining Control ................................................................................ 15-6Example 15.4 .......................................................................................... 156

Pressure Effects .................................................................................... 15-1 1Example 15.5 ........................................................................................ 15-1 4Completion/Workover Fluids ................................................................. 1 5-1 6Example 15.6 ........................................................................................ 15-1 8Example 75.7 ........................................................................................ 15-1 9Example 15.8 ........................................................................................ 1 5-20Example 15.9 ........................................................................................ 1 5-20

Example I5 . I0 ...................................................................................... 1 5-22Before the Job WC ................................................................................ 15-26Fluid Filtration ............................................................................................... 1527

Field Testing and Measurement of “Clean” ........................................... 15-32

Application ............................................................................................ .1 5-32Kill String Completions .......................................................................... 15-33

Returning Wells to Operation ................................................................ 15-33Workover References ................................................................................ 15-34Current Gravel Pack Design Methods and Problem Identification ........ 1 4-2 1

Snubbing ............................................................................................... 1 5-1 4. viii .References on Filtration ............................................................................. 15-35High Temperature, High Pressure Completions ................................................. 16-1

Completions Operations ................................................................................. 16-2Brines ............................................................................................................. 16-5Stimulation ...................................................................................................... 16-5Formation Damage ......................................................................................... 16-6Well Design .................................................................................................... 16-7Completions Equipment ................................................................................. 16-7Subsurface Safety Valves .............................................................................. 16-8Annular Pressure Buildup ............................................................................. 16-1 0

References ................................................................................................ 16-1 1Water Production Control ........................................................................................ 17-1Summary of Important Points .................................................................. 17-1Sources of Water ..................................................................................... 17-1Problem Definition - Reservoir ................................................................ 17-2Problem Definition - Near Wellbore ......................................................... 17-3Coning ..................................................................................................... 17-3Water Block ............................................................................................. 17-5Problem Definition - Injection Well .......................................................... 17-6Reservoir Description and Modeling Necessities .................................... 17-7

Treating Considerations .......................................................................... 17-7Modification of Permeability ............................................................................ 17-7Deep Modification - Permeability Reduction ........................................... 17-7..Deep Modification - Increasing Permeability ........................................... 17-7Shallow Modification - Permeability Reduction ........................................ 17-8Shallow Modification - Increasing Permeability ....................................... 17-9References .................................................................................................. 17-9Wireline and Coiled Tubing Operations ................................................................ 18-1Wireline Operations ................................................................................. 18-1Downhole Wireline Equipment ................................................................ 18-2Pressure and Fluid Control ...................................................................... 18-6Special Services ...................................................................................... 18-9Tools for Downhole Measurements ......................................................... 18-9Coil Tubing Operations

................................................................................ 18-9Chain Injector ........................................................................................ 1 8-1 0Axial Load Capacity ............................................................................... 18-25Depth Limitations .......................................................................................... 18-27Buoyancy ...................................................................................................... 18-28

Tapered Strings ............................................................................................ 18-30Buckling ........................................................................................................ 18-31Capacity and Displacement .......................................................................... 18-31Fluid Unloading in Casing ............................................................................. 18-40Friction Pressure .......................................................................................... 18-42Well Testing with Coiled Tubing ................................................................... 18-44References ................................................................................................ 18-44Additional References on Coiled Tubing ................................................... 18-46Workover Fishing ....................................................................................................... 19-1Location of Stuck Point ............................................................................ 19-6References . Fishing .................................................................................... 19-8References . Milling

..................................................................................... 19-8Plug and Abandonment Procedures ..................................................................... 20-1Legal Requirements ....................................................................................... 20-2Setting Cement Plugs ..................................................................................... 20-2Other Plugging Processes .............................................................................. 20-6Milling a Packer ....................................................................................... 20-7

References - Plug and Abandonment

.......................................................... 20-7Effects of Completion, Stimulation and Workover Activities on Surface FacilityOperations .............................................................................................................. 21-1Stimulation Flowbacks .................................................................................... 21-7Testing the Backflow ...................................................................................... 21-7Causes of Upsets .................................................................................... 21-7Flowback Duration ........................................................................................ 21 -1 2Treating the Returning Acid .......................................................................... 21-13Treatment Choices ....................................................................................... 21-13Oil Foams

..........................................................................................

........... 21-14

References ................................................................................................ 21 -1 4