Formulas and Calculations for Drilling, Production and Workover (eBook)

Norton J. Lapeyrouse (Autor)

eBook Download: PDF | EPUB

2002 | 2. Auflage
224 Seiten
Elsevier Science (Verlag)
978-0-08-050676-0 (ISBN)

Infos

The most complete manual of its kind, this handy book gives you all the formulas and calculations you are likely to need in drilling operations. New updated material includes conversion tables into metric. Separate chapters deal with calculations for drilling fluids, pressure control, and engineering. Example calculations are provided throughout.

Presented in easy-to-use, step-by-step order, Formulas and Calculations is a quick reference for day-to-day work out on the rig. It also serves as a handy study guide for drilling and well control certification courses. Virtually all the mathematics required out on the drilling rig is here in one convenient source, including formulas for pressure gradient, specific gravity, pump output, annular velocity, buoyancy factor, volume and stroke, slug weight, drill string design, cementing, depth of washout, bulk density of cuttings, and stuck pipe.


The most complete manual of its kind

New updated material includes conversion tables into metric

Example calculations are provided throughout

Inhalt

Cover 1
Formulas and Calculations for Drilling, Production, and Workover 4
Copyright Page 5
CONTENTS 6
PREFACE 8
CHAPTER 1. BASIC FORMULAS 10
Pressure Gradient 10
Hydrostatic Pressure 12
Converting Pressure into Mud Weight 13
Specific Gravity 14
Equivalent Circulating Density 15
Maximum Allowable Mud Weight 16
Pump Output 16
Annular Velocity 18
Capacity Formulas 21
Control Drilling 28
Buoyancy Factor 29
Hydrostatic Pressure Decrease When Pulling Pipe out of the Hole 29
Loss of Overbalance Due to Falling Mud Level 31
Formation Temperature 33
Hydraulic Horsepower 34
Drill Pipe/Drill Collar Calculations 34
Pump Pressure/Pump Stroke Relationship 36
Cost per Foot 37
Temperature Conversion Formulas 38
CHAPTER 2. BASIC CALCULATIONS 40
Volumes and Strokes 40
Slug Calculations 42
Accumulator Capacity 46
Bulk Density of Cuttings 50
Drill String Design (Limitations) 51
Ton-Mile Calculations 53
Cementing Calculations 56
Weighted Cement Calculations 62
Calculations for the Number of Sacks of Cement Required 63
Calculations for the Number of Feet to Be Cemented 66
Setting a Balanced Cement Plug 70
Differential Hydrostatic Pressure Between Cement in the Annulus and Mud Inside the Casing 74
Hydraulicing Casing 75
Depth of a Washout 79
Lost Returns„Loss of Overbalance 80
Stuck Pipe Calculations 81
Calculations Required for Spotting Pills 84
Pressure Required to Break Circulation 88
CHAPTER 3. DRILLING FLUIDS 90
Increase Mud Density 90
Dilution 94
Mixing Fluids of Different Densities 95
Oil-Based Mud Calculations 96
Solids Analysis 100
Solids Fractions 104
Dilution of Mud System 105
Displacement„Barrels of Water/Slurry Required 106
Evaluation of Hydrocyclone 106
Evaluation of Centrifuge 108
CHAPTER 4. PRESSURE CONTROL 112
Kill Sheets and Related Calculations 112
Prerecorded Information 124
Kick Analysis 133
Pressure Analysis 146
Stripping/Snubbing Calculations 148
Subsea Considerations 153
Workover Operations 162
Controlling Gas Migration 166
Gas Lubrication 168
Annular Stripping Procedures 170
CHAPTER 5. ENGINEERING CALCULATIONS 174
Bit Nozzle Selection„Optimized Hydraulics 174
Hydraulics Analysis 178
Critical Annular Velocity and Critical Flow Rate 182
dŽ Exponent 183
Cuttings Slip Velocity 184
Surge and Swab Pressures 188
Equivalent Circulation Density 196
Fracture Gradient Determination„Surface Application 199
Fracture Gradient Determination„Subsea Application 203
Directional Drilling Calculations 206
Miscellaneous Equations and Calculations 212
APPENDIX A 218
APPENDIX B 226
INDEX 230

Textauszug

CHAPTER ONE BASIC FORMULAS

Pressure Gradient

Pressure gradient, psi/ft, using mud weight, ppg

psi/ft = mud weight, ppg × 0.052

Example: 12.0ppg fluid

psi/ft = 12.0ppg × 0.052

psi/ft = 0.624

Pressure gradient, psi/ft, using mud weight, lb/ft3

psi/ft = mud weight, lb/ft3 × 0.006944

Example: 100lb/ft3 fluid

psi/ft = 100lb/ft3 × 0.006944

psi/ft = 0.6944

OR

psi/ft = mud weight, lb/ft3 ÷ 144

Example: 100lb/ft3 fluid

psi/ft = 100lb/ft3 ÷ 144

psi/ft = 0.6944

Pressure gradient, psi/ft, using mud weight, specific gravity (SG)

psi/ft = mud weight, SG × 0.433

Example: 1.0 SG fluid

psi/ft = 1.0SG × 0.433

psi/ft = 0.433

Metric calculations

Pressure gradient, bar/m = drilling fluid density kg/l × 0.0981

Pressure gradient, bar/10m = drilling fluid density kg/l × 0.981

S.I. units calculations

Pressure gradient, kPa/m = drilling fluid density, kg/m3 ÷ 102

Convert pressure gradient, psi/ft, to mud weight, ppg

ppg = pressure gradient, psi/ft ÷ 0.052

Example: 0.4992psi/ft

ppg = 0.4992psi/ft ÷ 0.052

ppg = 9.6

Convert pressure gradient, psi/ft, to mud weight, lb/ft3

lb/ft3 = pressure gradient, psi/ft ÷ 0.006944

Example: 0.6944psi/ft

lb/ft3 = 0.6944psi/ft ÷ 0.006944

lb/ft3 = 100

Convert pressure gradient, psi/ft, to mud weight, SG

SG = pressure gradient, psi/ft ÷ 0.433

Example: 0.433psi/ft

SG = 0.433psi/ft ÷ 0.433

SG = 1.0

Metric calculations

Drilling fluid density, kg/l = pressure gradient, bar/m ÷ 0.0981

Drilling fluid density, kg/l = pressure gradient, bar/10m ÷ 0.981

S.I. units calculations

Drilling fluid density, kg/m3 = pressure gradient, kPa/m × 102

Hydrostatic Pressure (HP)

Hydrostatic pressure using ppg and feet as the units of measure

HP = mud weight, ppg × 0.052 × true vertical depth (TVD), ft

Example:

HP = 13.5ppg × 0.052 × 12,000ft

HP = 8424psi

Hydrostatic pressure, psi, using pressure gradient, psi/ft

HP = psi/ft × true vertical depth, ft

Example:

HP = 0.624psi/ft × 8500ft

HP = 5304psi

Hydrostatic pressure, psi, using mud weight, lb/ft3

HP = mud weight, lb/ft3 × 0.006944 × TVD, ft

Example:

HP = 90lb/ft3 × 0.006944 × 7500ft

HP = 4687psi

Hydrostatic pressure, psi, using meters as unit of depth

HP = mud weight, ppg × 0.052 × TVD, m × 3.281

Example:

HP = 12.2ppg × 0.052 × 3700 × 3.281

HP = 7701psi

Metric calculations

S.I. units calculations

Converting Pressure into Mud Weight

Convert pressure, psi, into mud weight, ppg, using feet as the unit of measure

Mud weight, ppg = pressure, psi ÷ 0.052 ÷ TVD, ft

Example:

Convert pressure, psi, into mud weight, ppg, using meters as the unit of measure

Mud weight, ppg = pressure, psi ÷ 0.052 ÷ TVD, m ÷ 3.281

Example:

Mud wt, ppg = 3583psi ÷ 0.052 ÷ 2000m ÷ 3.281

Metric calculations

S.I. units calculations

Specific Gravity (SG)

Specific gravity using mud weight, ppg

SG = mud weight, ppg ÷ 8.33

Example: 15.0ppg fluid

SG = 15.0ppg ÷ 8.33

SG = 1.8

Specific gravity using pressure gradient, psi/ft

SG = pressure gradient, psi/ft ÷ 0.433

Example: pressure gradient = 0.624psi/ft

SG = 0.624psi/ft ÷ 0.433

SG = 1.44

Specific gravity using mud weight, lb/ft3

SG = mud weight, lb/ft3 ÷ 62.4

Example: mud weight = 120lb/ft3

SG = 120lb/ft3 ÷ 62.4

SG = 1.92

Convert specific gravity to mud weight, ppg

Mud weight, ppg = specific gravity × 8.33

Example: specific gravity = 1.80

Convert specific gravity to pressure gradient, psi/ft

psi/ft = specific gravity × 0.433

Example: specific gravity = 1.44

psi/ft = 1.44 × 0.433

psi/ft = 0.624

Convert specific gravity to mud weight, lb/ft3

lb/ft3 = specific gravity × 62.4

Example: specific gravity = 1.92

lb/ft3 = 1.92 × 62.4

lb/ft3 = 120

Equivalent Circulating Density (ECD), ppg

Metric calculation

S.I. units calculations

Maximum Allowable Mud Weight from Leak-off Test Data

Pump Output (PO)

Triplex Pump

Formula 1

Example: Determine the pump output, bbl/stk, at 100% efficiency for a 7-in. by 12-in. triplex pump:

PO @ 100% = 0.000243 × 72 × 12

PO @100% = 0.142884bbl/stk

Adjust the pump output for 95% efficiency:

Decimal equivalent = 95 ÷ 100 = 0.95

PO @ 95% = 0.142884bbl/stk × 0.95

PO @ 95% = 0.13574bbl/stk

Formula 2

PO, gpm = [3(D2 × 0.7854) S] 0.00411 × SPM

Example: Determine the pump output, gpm, for a 7-in. by 12-in. triplex pump at 80 strokes per minute:

Duplex Pump

Formula 1

Example: Determine the output, bbl/stk, of a 5–1/2in. by 14-in. duplex pump at 100% efficiency. Rod diameter = 2.0in.:

Adjust pump output for 85% efficiency:

Decimal equivalent = 85 ÷ 100 = 0.85

PO @ 85% = 0.128142bbl/stk × 0.85

PO @ 85% = 0.10892bbl/stk

Formula 2

Example: Determine the output, bbl/stk, of a 5–1/2-in. by 14-in. duplex pump @ 100% efficiency. Rod diameter = 2.0in.:

PO @ 100% = 0.000162 × 14 × [2(5.5)2 – 22]

PO @ 100% = 0.000162 × 14 × 56.5

PO @ 100% = 0.128142bbl/stk

Adjust pump output for 85% efficiency:

PO @ 85% = 0.128142bbl/stk × 0.85

PO @ 85% = 0.10892bbl/stk

Metric calculation

Pump output, liter/min = pump output, liter/stk × pump speed, spm

S.I. units calculation

Pump output, m3/min = pump output, liter/stk × pump speed, spm

Annular Velocity (AV)

Annular velocity (AV), ft/min

Formula 1

AV = pump output, bbl/min ÷ annular capacity, bbl/ft

Formula 2

Formula 3

Annular velocity (AV), ft/sec

Metric calculations

Annular velocity, m/min = pump output, liter/min ÷ annular volume, l/m

Annular velocity, m/sec = pump output, liter/min ÷ 60 ÷ annular volume, l/m

S.I. units calculations

Annular velocity, m/min = pump output, m3/min ÷ annular volume, m3/m

Pump output, gpm, required for a desired annular velocity, ft/min

Strokes per minute (SPM) required for a given annular velocity

Capacity Formulas

Annular capacity between casing or hole and drill pipe, tubing, or casing

Annular capacity between casing and multiple strings of tubing

a) Annular capacity between casing and multiple strings of tubing, bbl/ft:

b) Annular capacity between casing and multiple strings of tubing, ft/bbl:

c) Annular capacity between casing and multiple strings of tubing, gal/ft:

d) Annular capacity between casing and multiple strings of tubing, ft/gal:

e) Annular capacity between casing and multiple strings of tubing, ft3/linft:

f) Annular capacity between casing and multiple strings of tubing, linft/ft3:

Capacity of tubulars and open hole: drill pipe, drill collars, tubing, casing, hole, and any cylindrical object

Amount of cuttings drilled per foot of hole drilled

a) BARRELS of cuttings drilled per foot...

Produkt-Details

• Erscheint lt. Verlag: 19.12.2002
• Sprache: englisch
• Themenwelt: Mathematik / Informatik ► Mathematik ► Angewandte Mathematik
• Themenwelt: Naturwissenschaften ► Geowissenschaften ► Geologie
• Themenwelt: Technik ► Bergbau
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• ISBN-10: 0-08-050676-3 / 0080506763
• ISBN-13: 978-0-08-050676-0 / 9780080506760