Formulas and Calculations for Drilling, Production and Work-over

Lapeyrouse

Table of contents :
CONTENTS……Page 2
BASIC FORMULAE……Page 4
Pressure Gradient……Page 5
Converting Pressure into Mud Weight……Page 6
Specific Gravity (SG)……Page 7
Pump Output (P0)……Page 8
Annular Velocity (AV)……Page 10
Capacity Formulas……Page 12
Control Drilling……Page 17
Hydrostatic Pressure (HP) Decrease When POOH……Page 18
Loss of Overbalance Due to Falling Mud Level……Page 20
Drill Pipe/Drill Collar Calculations……Page 21
Pump Pressure/Pump Stroke Relationship……Page 23
Temperature Conversion Formulas……Page 24
BASIC CALCULATIONS……Page 26
Volumes and Strokes……Page 27
Slug Calculations……Page 28
Accumulator Capacity — Usable Volume Per Bottle……Page 31
Bulk Density of Cuttings (Using Mud Balance)……Page 33
Drill String Design (Limitations)……Page 34
Ton-Mile (TM) Calculations……Page 35
Cementing Calculations……Page 38
Weighted Cement Calculations……Page 43
Calculations for the Number of Sacks of Cement Required……Page 44
Calculations for the Number of Feet to Be Cemented……Page 46
Setting a Balanced Cement Plug……Page 49
Differential Hydrostatic Pressure Between Cement in Annulus and Mud inside casing……Page 51
Hydraulicing Casing……Page 53
Depth of a Washout……Page 55
Lost Returns — Loss of Overbalance……Page 56
Stuck Pipe Calculations……Page 57
Calculations Required for Spotting Pills……Page 60
Pressure Required to Break Circulation……Page 62
DRILLING FLUIDS……Page 64
Increase Mud Density……Page 65
Mixing Fluids of Different Densities……Page 68
Oil Based Mud Calculations……Page 70
Solids Analysis……Page 73
Dilution of Mud System……Page 76
Displacement — Barrels of Water/Slurry Required……Page 77
Evaluation of Hydrocyclone……Page 78
Evaluation of Centrifuge……Page 79
PRESSURE CONTROL……Page 82
Kill Sheets and Related Calculations……Page 83
Maximum Anticipated Surface Pressure……Page 93
Formation Pressure Tests……Page 95
Maximum Allowable Shut-in Casing Pressure……Page 97
Maximum Influx Height……Page 98
Adjusting Maximum Allowable Shut-in Casing Pressure For an Increase in MW……Page 99
Shut-in Drill Pipe Pressure (SIDPP)……Page 100
Height, Fl, of Influx……Page 101
Gas Migration in a Shut-in Well……Page 102
Hydrostatic Pressure Decrease at TD Caused by Gas Cut Mud……Page 103
Maximum Pressures When Circulating Out a Kick (Moore Equations)……Page 104
Gas Flow Into the Wellbore……Page 108
Hydrostatic Pressure Exerts by Each Barrel of Mud in the Casing……Page 109
Surface Pressure During Drill Stem Tests……Page 110
Breakover Point Between Stripping and Snubbing……Page 111
Casing Pressure Increase From Stripping Into Influx……Page 112
Maximum Allowable Surface Pressure (MASP) Governed by the Formation……Page 113
Pressure Chart for Bringing Well on Choke……Page 114
Casing Burst Pressure — Subsea Stack……Page 115
Adjusting Choke Line Pressure Loss for a Higher Mud Weight……Page 117
Maximum Mud Weight with Returns Back to Rig Floor……Page 118
Bottomhole Pressure When Circulating Out a Kick……Page 119
Bullheading……Page 120
Lubricate and Bleed……Page 122
ENGINEERING CALCULATIONS……Page 125
Bit Nozzle Selection — Optimised Hydraulics……Page 126
Hydraulics Analysis……Page 129
Critical Annular Velocity and Critical Flow Rate……Page 131
“d” Exponent……Page 132
Cuttings Slip Velocity……Page 133
Surge and Swab Pressures……Page 136
Equivalent Circulation Density (ECD)……Page 141
Fracture Gradient Determination – Surface Application……Page 143
Fracture Gradient Determination – Subsea Applications……Page 146
Directional Drilling Calculations……Page 148
Directional Survey Calculations……Page 149
Dogleg Severity Calculation……Page 151
Surface Equipment Pressure Losses……Page 153
Annular Pressure Losses……Page 154
Pressure Loss Through Common Pipe Fittings……Page 155
Critical RPM……Page 156
HEAVY WEIGHT DRILL PIPE (API)……Page 158
DRILL PIPE (METRIC)……Page 159
DRILL COLLAR CAPACITY AND DISPLACEMENT……Page 160
Rectangular Tanks with Sloping Sides:……Page 161
Tapered Cylindrical Tanks:……Page 162
Horizontal Cylindrical Tank:……Page 163
Circulation Rate……Page 165
Power……Page 166
Volume……Page 167
INDEX……Page 168