NORSOK m-506r2 (06-2005)

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DialogStart

NORSOK M-506 Corrosion Rate Model, Rev. 2, June 2005

Continue Exit Information

The NORSOK M-506 corrosion rate model calculates the CO2 corrosion rate on basis of given temperature, pH, CO2 partial pressure and shear stress. The model is valid for temperature 5 - 150 °C, pH 3.5 - 6.5,

CO2 partial pressure 0.1 - 10 bar and shear stress 1 - 150 Pa.

The model is not applicable when the H2S partial pressure is higher than 0.5 bar, or when the ratio between the partial pressure of CO2 and H2S is less than 20. The model can lead to underprediction of the corrosion rate when the total content of organic acids exceeds 100 ppm and the CO2 partial pressure is less than 0.5 bar.

NORSOK M-506

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NORSOK M-506 Main menu

Corrosion rate without inhibitor effect Calculate corrosion rate

0 0 °C bar mole% CO2 pressure CO2 fugacity Calculate shear stress

Calculate pH

Parameter study Accumulated corrosion

Calculate humidity Print

Save in new file / Load file Save in current file

Show current file Help Exit Project Identifier Equipment Temperature Pressure

Mole percent CO2 in gas Shear stress pH Glycol concentration Inhibitor efficiency Comment CO2 fugacity Use as input: Pa % % bar mm/year Input

Run the corrosion rate model

Options on input

Options

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DialogHum

NORSOK M-506 Humidity Menu

Calculate test 6 200 10 1 100 OK Cancel Print

Save in new file/Load file Save in current file

Show current file Help Project Identifier Equipment Temperature Pressure Water mass flow Total mass flow

Comment Relative humidity Dew point °C bar kmole/h kmole/h % °C Input Run Output Options Page 4

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DialogFlow

NORSOK M-506 Flow Menu

Calculate 11 5 1 0 11 11 °C bar m/s MSm³/day OK Cancel Print Save in new file/Load file

Save in current file Show current file

Expert input Help 50 0.9 0.8 1024 850 6.254 1.334 1.1 0.03 0.5 7.06 cp cp cp Project Identifier Equipment Temperature Pressure

Superficial liquid velocity Gas flow Watercut Diameter (ID) Comment Shear stress Liquid viscosity Default Roughness Compressibility Specific gravity Water density Oil density Gas density Water viscosity Oil viscosity Gas viscosity Inversion point Max rel. liq. visc. % mm Pa cp µm kg/m³ kg/m³ kg/m³ Input Run Output Options Other input

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DialogFlow

NORSOK M-506 Flow Menu

cp cp cp kg/m³ kg/m³ kg/m³ Options Other input Page 6

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DialogBicarb

NORSOK M-506 pH Menu Calculate 60 5 1 Condensed water Formation water °C bar bar OK Cancel Print

Save in new file/Load file Save in current file

Show current file Help Project Identifier Equipment Temperature Pressure

Mole percent CO2 in gas

Comment

Calculated pH

pH in condensed water saturated with Fe2+ Input

Run

Output

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DialogBicarb

NORSOK M-506 pH Menu

pH in condensed water saturated with Fe2+ Output

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DialogChart

NORSOK M-506 Parameter Study

Update chart Temperature 20 150 pH 3.5 4.5 5.5 1E-5 10 5 0 0 Default CO2 pressure = 1E-5 bar, Shear stress = 10 Pa,

Return Print Save Help Zoom Zoom Range Min Max °C °C 1. value 3. value 2. value CO2 pressure Shear stress Pressure Glycol conc. Inh. efficiency bar Pa bar % %

1. variable parameter 2. variable parameter Other input parameters Options

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DialogAcc

NORSOK M-506 Accumulated Corrosion

CO2 Return 1 jan-2002 des-2002 60 5 1 4 4 0 0 Calc pH Calc shear Acc. off Show chart Help Insert line Delete line Clear table Zoom in Zoom out Print Save Load Line number Start date End date Temperature Pressure Shear stress pH Glycol conc. Inhibitor eff. °C bar bar Pa % % Input Options

Page 10

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DialogHelp

NORSOK M-506 Help Menu

OK

THE SAVE MENU

The save menu provides two different alternatives: 1. Save data in a new separate Excel file

2. Load a previous saved Excel file and add saved data to this file

If it is wanted to save data in a new separate Excel file the parameters that are supposed to be saved must be turned on in this save menu. Click the button called "Create new file" when the desired parameters are turned on, and then the program will ask for the file name before the program returns to the previous shown menu. In this case the current data will be saved as the first set of data in the new file. If it is wanted to use a previous saved file to save new data the file can be loaded by pressing the Load button. In such cases it has no meaning to turn on or off any parameters in the save menu because the same parameters that have been saved in the loaded file earlier will still be saved in this file. When a file is loaded in this way the actual parameters will not be saved automatic. The data will only be saved by clicking the buttons called "Save in current file" in the different menus.

Click the Cancel button to return to the previous menu without creating a new file or loading an old file.

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DialogSave

NORSOK M-506 Save Menu

Calculated liquid viscosity

Create new file Load file Cancel Help

Project Equipment Identifier Comment Temperature Pressure Total mass flow CO2 mass flow

Mole% CO2 CO2 pressure CO2 fugacity Shear stress pH Glycol concentration Inhibitor efficiency

Glycol correction factor

Corrosion rate without inhibitor or glycol effect Corrosion rate with inhibitor or glycol effect

Bicarbonate

Ionic strength Calculated pHpH in solution satureted with Fe2+ Superficial liquid velocity

Superficial gas velocity Liquid flow Gas flow Watercut Diameter (ID) Water density Oil density Gas density Water viscosity Oil viscosity Gas viscosity Inversion point Max rel. liq. viscosity

Roughness Spesific gravity Compressibility Calculated shear stress

Water mass flow Relative humidity Dew point

Choose which paramaters to save All menues Humidity menu Main menu pH menu Flow menu Page 12

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DialogSave

NORSOK M-506 Save Menu

Calculated liquid viscosity

Help

Corrosion rate without inhibitor or glycol effect

Calculated shear stress All menues

Humidity menu Main menu

pH menu

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DialogShow Show Data Return Print Help Zoom in Zoom out Page 14

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SheetModell

Input

Temperature (°C) 60 Glycol factor 1

pCO2 (bar) 2

pH 5 Inhibitor factor 1

Shear stress (Pa) 19

Result

Corrosion rate (mm/y) 11.0291465 CR with inhibitor effect 11.02915 Calculations

Lowest temp 60

Highest temp 80

Lowest temp. Highest temp. 5 °C

K 10.695 9.949 pCO2 factor 1.53687518 1.53687518 Shear factor 1 1 pH factor 0.671 0.60360857 0.857 Corrosion rate 11.0291465 9.22939911 a -0.0899874 b 16.4283888

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SheetModell Used pCO2 2 Used pH 5 Used shear 19 15 °C 20 °C 40 °C 60 °C 80 °C 90 °C 120 °C 150 °C 0.801 0.782 0.782 0.671 0.603609 0.39016 0.1902 0.0365 Page 16

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158732639.xls.ms_office 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 A B C D E F G H I J K L

INPUT QL SM/D 8.2067 QG MMSM3/D 0 VISC.O CP 1.1 LIM 1.53366

ROUGH 5.00E-05 WC 0.11 D(M) 0.011 SP.GR 0.8 RO.O 8.50E+02 kg/m3 T 11 P(BAR) 5 Z 0.9

RO.L 869.14 RO.G 6.25404 R0.GSC 0.96478 VISC.W 1.3336 Waterdensity 1024

VISC.L 1.51133 VL(M/S) 1 VG(M/S) 0 VM(M/S) 1

VISC.G 0.03LAMDA 1 VISC.M 1.51133 RO.M 869.14

2 2 Cr0.5

FLOW SMOOTH

REGIME: PIPE

REGIME VG CRIT 18.5292 M/S LIQUID 623.557 YEARS TO FAILURE OF ST52 STEEL BY MESA ATTACK VL CRIT 0.24162 M/S ************************************************************************************************ VL CRIT 0.27 M/S OBSTACLE 507.703 YEARS TO FAILURE POSSIBLESTRAT SLUG ANNULAR ATOMIZED LIQUID LIQUID, STRATIFIED,DISPERSED,ANNULAR NLIM= 2.84E+12 RE 6325.91

YIELD= 426 Pa FRICT 0.01001 OBSTACLE:

SMOOTH PIPE: TAU 4.34977 REL-AMP 0.94

EXPONENT 0.99742 V EQ 1 EXPONENT 0.99025

LIFETIME 623.557 YEARS F 134 LIFETIME 507.703 YEARS

CANNOT EXEED: 623.557 YEARS TAUAMP 1.08744 CANNOT EXEED: 507.703 YEARS

227598 DAYS 185311 DAYS

FATIGUE IF TREATED AS SLUG FLOW

RE 6324.56 HOLD UP 0.98345 0.98345 ALPHA L 0.98345 ROM 854.859 VISCM 1.48681 FO 0.01001 OBSTACLE: TAUW 6.16099 REL-AMP 0.94

EXPONENT 0.99912 TAUAMP 0.36966 EXPONENT 0.99025

LIFETIME 16085 YEARS F-SLUG 5.45455 LIFETIME 12472.6 YEARS

CANNOT EXEED: 16085 YEARS L-UNIT 0.22 M CANNOT EXEED: 12472.6 YEARS

5871029 DAYS L-SLUG 0.22 M 4552486 DAYS

TAUMEAN 4.34977 PA Taumean slug: 0.31161 TOO LOW !

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NORSOK M-506

Calculated results from the NORSOK M-506 CO

2

corrosion rate model

Equipment Identifier Temperature Pressure

CO2 partial

pressure mole% CO2 CO2 fugacity Shear stress pH

Inhibitor efficiency

°C bar bar % bar Pa %

c 20 1 0.1 10 0.1 10 5 0

c 68 1 0.16 16 0.16 10 5 0

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NORSOK M-506 Glycol concentration Glycol reduction factor Spesific gravity Water viscosity Maximum relative liquid viscosity Corrosion rate without inhibitor effect Corrosion rate with inhibitor

or glycol effect Comment

% cp mm/year mm/year

0 1 0.8 1.089 7.06 0.83 0.83

10 0.84 0.8 1.089 7.06 0.83 0.7

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NORSOK M-506

0

0.002

0.004

0.006

0.008

0.01

0.012

3.5

53.5

103.5

153.5

203.5 C

orr

osion

rate

/

(m

m

/y

ear

)

Temperature / (°C)

Pressure = 55 bar, Shear stress = 64 Pa, CO2 = 5 mole%

pH=4

pH=5

pH=6

0

0.002

0.004

0.006

0.008

0.01

0.012

0

50

100

150

200 Corros

ion

rat

e

/ (m

m/y

ear)

Temperature / (°C)

CO2 pressure = 1E-5 bar, Shear stress = 10 Pa,

pH=4

pH=5

pH=6

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SheetAccChart 0 0.2 0.4 0.6 0.8 1 1.2 0 200 400 600 800 1000 1200 1400 1600 1800 2000 Corr osi on r a te / (m m/y e a r) Time / date

Corrosion

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 200 400 600 800 1000 1200 1400 1600 1800 2000 A ccum u lat ed co rr o sion / mm Time / date

Accumulated corrosion

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M506Chart

Calculated results from the NORSOK M-506 CO

2

corrosion model, rev. 2

Temperature / (°C) pH=3.5 pH=4.5 pH=5.5 20 4.427861 3.616083 1.884596 26.5 5.686505 4.643975 2.420303 33 6.945149 5.671867 2.95601 39.5 8.203793 6.699759 3.491717 46 8.65226 7.156366 3.369722 52.5 9.033212 7.565365 3.192918 59 9.414164 7.974365 3.016114 65.5 9.69586 7.920688 2.815738 72 9.959509 7.782889 2.611077 78.5 10.22316 7.64509 2.406415 85 8.602593 6.189111 1.482072 91.5 6.890631 4.747182 0.618993 98 6.758233 4.67026 0.679807 104.5 6.625835 4.593339 0.740621 111 6.493436 4.516417 0.801435 117.5 6.361038 4.439496 0.862249 124 5.980939 3.917955 0.786504 130.5 5.446028 3.118527 0.62541 137 4.911116 2.319099 0.464316 143.5 4.376205 1.519671 0.303222 150 3.841293 0.720242 0.142128

CO2 pressure 1 bar

Shear stress 5 Pa

Trykk 80 bar

Glycol concentration 0 % (concentration) Inhibitor reduction factor 0

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 A B C D E F G H I J K L M N O P Q

Actual dialog number 0 use pressure or fugacity1 pressure in B9

Recent dialog number 1 Use of expertmenu in dialog flow1 1

Dialog to check the input 0

INPUTPARAMETER VALUE lovlig inputny input hvis kolonne C = FALSEmin max unit choiseunit value in model unitsunit Old value in case of cancelOld unit Calculation of other parameters

Temperature FALSE 5 150 1 °C 0 C 60 1

pH FALSE 3.5 6.5 0 4

CO2 content in gas FALSE FALSE 0.09 10 3 mole% 0 bar (CO2 trykk) 1 1 fugasity of CO2 in bar0 fugasity in chosen unit (in bar if mole% or flow is chosen)0

Shear stress FALSE 1 150 Pa 0 Pa 10

Trykk FALSE 1 1000 1 bar 0 bar 5 1 fugasitycoeffisient 1

Glycol concentration 0 TRUE 0 100 % (concentration) 1 fraction 0

Inhibitor reduction factor 0 TRUE 0 100 % 1 fraction 0

Liquid flow FALSE 0 13564.8 1 Sm3/day 0 Sm3/day 0 1

Gas flow TRUE 0 0.2812 1 MSm3/day 0 Sm3/day 1

Watercut FALSE 100 0 100 0

Diameter (ID) FALSE 100 0 mm 0 m

Inversion point use default TRUE 0.5 0.3 0.9 0.5 use default

max relative liq visc use default TRUE 7.06 1 100 1 7.06 cp use default

Tetthet vann use default TRUE 1024 995 1050 kg/m3 1024 kg/m3 use default lign for vanntetthet sfa T er gitt i celle Q20, kopieres evt til Celle B201000 Viskositet vann use default TRUE 1 0.17 1.1 1 cp 1 cp use default 1 Liquid viscositet 0 cp

Tetthet olje use default TRUE 850 600 1100 kg/m3 850 kg/m3 use default Viskositet olje use default TRUE 1.1 0.2 200 1 cp 1.1 cp use default tetthet gass use default TRUE 10 1 1700 kg/m3 10 kg/m3 use default viskositet gass use default TRUE 0.03 0.02 0.06 1 cp 0.03 cp use default

Ruhet use default TRUE 50 0 100 um 0.00005 m use default

Z use default TRUE 0.9 0.8 1 0.9 use default

sp.gr use default TRUE 0.8 0.5 1 0.8 use default

Total mass flow TRUE 1 0.001 1000000 kmole/h 0 kmole/h

Alle input OK FALSE

grafisk fremstilling beregning av verdier for grafisk fremstilling

Temperature / (°C) pH=4 pH=5 pH=6 Temperature / (°C)pH=4 pH=5 pH=6 20 0.004757 0.00389 0.00203 20 0.00476 0.00389 0.00203 26.5 0.006109 0.00499 0.0026 26.5 0.00611 0.00499 0.0026 33 0.007461 0.00609 0.00318 33 0.00746 0.00609 0.00318 39.5 0.008813 0.0072 0.00375 39.5 0.00881 0.0072 0.00375 46 0.009295 0.00769 0.00362 46 0.0093 0.00769 3.62E-03 52.5 0.009704 0.00813 0.00343 52.5 0.0097 0.00813 3.43E-03 59 0.010113 0.00857 0.00324 59 0.01011 0.00857 3.24E-03 65.5 0.010416 0.00851 0.00303 65.5 0.01042 0.00851 3.03E-03 72 0.010699 0.00836 0.00281 72 0.0107 0.00836 2.81E-03 78.5 0.010983 0.00821 0.00259 78.5 0.01098 0.00821 2.59E-03 85 0.009242 0.00665 0.00159 85 0.00924 0.00665 1.59E-03 91.5 0.007402 0.0051 0.00067 91.5 0.0074 0.0051 6.65E-04 98 0.00726 0.00502 0.00073 98 0.00726 0.00502 7.30E-04 104.5 0.007118 0.00494 0.0008 104.5 0.00712 0.00494 7.96E-04 111 0.006976 0.00485 0.00086 111 0.00698 0.00485 8.61E-04 117.5 0.006834 0.00477 0.00093 117.5 0.00683 0.00477 9.26E-04 124 0.006425 0.00421 0.00085 124 0.00643 0.00421 8.45E-04 130.5 0.005851 0.00335 0.00067 130.5 0.00585 0.00335 6.72E-04 137 0.005276 0.00249 0.0005 137 0.00528 0.00249 4.99E-04 143.5 0.004701 0.00163 0.00033 143.5 0.0047 0.00163 3.26E-04 150 0.004127 0.00077 0.00015 150 0.00413 0.00077 1.53E-04

Opsjoner for grafisk fremstilling

choise Parameter Unit Label on button on DialogChartUse default options use velocity or shear stress 1 Shear stressPa velocity TRUE

chartlist 1 chartlist 2 Temperature pH pH Pressure Pressure Shear stress Shear stress

1.parameter 2. parameter3. parameter4. parameter

Valgt index 1 1 Old value for first parameter1

Valgt parameter Temperature pH Pressure Shear stress

unit °C bar Pa

input in line 7 8 11 10

line in model 2 4 6 5

Lovlig min max Default Value in model unit

Range, min 5 TRUE 5 5 5

Range, max 150 TRUE 150 150 150

1. value 4 TRUE 3.5 6.5 4.25 4

2. value 5 TRUE 3.5 6.5 5 5

3. value 6 TRUE 3.5 6.5 5.75 6

All legal TRUE

Options for accumulated corrosion

time,end Dec-2005

Show chart or table : 1 Show Table Label on ButtonShow:Show chart time,start Jan-2005 LineNumber 1 1 Data saved 0 FALSE Integrated chart or not : 1 Integrated Label on ButtonIntegrate:Acc. off legal time and lineTRUE Min time 0 Max time 73200 Accumulated dialog activated0 FALSE

legal line TRUE

Options for calculation of pH

INPUTPARAMETER VALUE lovlig input ny input hvis kolonne C = FALSEmin max unit choiseunit value in model unitsunit Old value in case of cancelOld unit

Bicarbonate 0 TRUE 0 0 32000 2 mg/l 0 M 0 2 Use condenced water 1 TRUE

Ionic strenght 0 TRUE 0 0 175 2 g/l 0 M 0 2 Saturated pH

Options for calculation of maximum flow rate

INPUTPARAMETER VALUE lovlig input ny input hvis kolonne C = FALSEmin max Ratio gas/liquid flow 0.00E+00 TRUE 0 0 1E+12

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105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 A B C D E F G H I J K L M N O P Q Saving status 1 1 1 1 1 0 1 1 0 1 0 0 0 0 0 0 Default status 1 1 1 1 1 0 1 1 0 1 0 0 0 0 0 0

Current dialog status 2 default Saving macro turned on0 FALSE Data saved yet 0 FALSE Next line in sheet M506Data 8

Units when saving 1 1 3 1

Shear stress calculations

St52 Cr0.5

Max recommended shear stress

Max recommended liquid superficial velocitym/s Sm3/day m/s Sm3/day Max recommended gas superficial velocitym/s MSm3/day m/s MSm3/day DialogHeight small

Sheets position

Sheet line column old line old column

SSH97Data 1 1 1 1

Calculation of humidity

flow/kmole/h min max legal all input legalOld value

Flow of H2O 0.001 1000000 FALSE FALSE

Total flow 0.001 1000000 FALSE

vanndamptrykk 1.55E+01 bar

Saturation temperature C Relativ fuktighet %

Data for plot of accumulated corrosion

Line start date end date time periode / yeartime Acc corr

0 1900 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 R S T U V W X Y Z AA AB AC AD AE AF AG AH AI Old value 1

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105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 R S T U V W X Y Z AA AB AC AD AE AF AG AH AI 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 2

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 AJ AK AL AM AN AO AP AQ AR AS AT AU AV AW AX AY AZ BA

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105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 AJ AK AL AM AN AO AP AQ AR AS AT AU AV AW AX AY AZ BA 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 1 1

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 BB BC BD BE

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105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 BB BC BD BE 0 1 1 1 0 0 0 1

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x

Calculated results from NORSOK M-506

Project

a

Equipment

a

Identifier

c

Comment

d

INPUT

Temperature

90 °C

Pressure

10 bar

Total mass flow

-

kmole/h

CO

₂

content in gas

10 mole%

Shear stress

10 Pa

pH

5 Glycol concentration

10 %

Inhibitor efficiency

5 %

OUTPUT

CO

2

fugacity

0.98 bar

Glycol reduction factor

0.8449

Corrosion rate

2.2 mm/year

Corrosion rate with inhibitor or glycol effect

1.9 mm/year

(32)

x

Calculated results from NORSOK M-506

Project

Equipment

Identifier

Comment

INPUT

Temperature

30 °C

Pressure

10 bar

Total mass flow

-

kmole/h

CO

2

content in gas

10 mole%

Bicarbonate concentration

mg/l

Ionic strength

g/l

OUTPUT

pH

3.9 pH in condensed water saturated with Fe

2+

5

x

(33)

x

Calculated results from NORSOK M-506

Project

ssh

Equipment

a

Identifier

v

Comment

test

INPUT

Temperature

20 °C

Pressure

10 bar

Total mass flow

100 kmole/h

Water mass flow

2 kmole/h

OUTPUT

Relative humidity

855.2 %

Dew point

60 °C

(34)

x

Calculated results from NORSOK M-506

Project

Equipment

Identifier

Comment

INPUT

Temperature

50 °C

Pressure

10 bar

Superficial liquid velocity

6 m/s

Superficial gas velocity

6 m/s

Watercut

100 Diameter (ID)

100 mm

Water density

1024

kg/m

3

Oil density

850 kg/m

3

Gas density

10.83 kg/m

3

Water viscosity

0.5956

cp

Oil viscosity

1.1 cp

Gas viscosity

0.03 cp

Maximum relative liquid viscosity

0.5956

Inversion point

0.5 Maximum relative liquid viscosity

7.06 Rougness

5.00E-05

µm

Compressibility

0.9 Specific gravity

0.8 OUTPUT

Liquid viscosity

0.5956

cp

Shear stress

-17

Pa

x 7/18/2013

(35)

SheetHelp

ABOUT THE NORSOK M-506 CORROSION RATE CALCULATION MODEL

This computer program is developed based on the corrosion rate model given as equations in this Standard. The corrosion rate equations given in NORSOK M-506 describe the formal model which shall apply, while the computer program itself is an optional aid which the users of the model may apply such that they possess an efficient tool to conduct corrosion rate calculations and parameter studies.

It is an overall principle for the use of this program that the program is an aid in CO2 corrosion rate assessments, but that the user of the program is responsible for the results and the final material selections. Therefore the user of the program must perform a critical evaluation of all results and the applicability of these in each case and in each system/part of a system.

As the computer program is distributed electronically and may be used on computers and program versions outside the control of NTS/NORSOK, users of the computer program are sole responsible to verify that the computer calculations are in accordance with the equations in this standard.

The CO2 corrosion rate calculation program shall only be used by experienced material engineers.

The program covers only calculation of corrosion rates where CO2 is the corrosive agent. It does not include additional effects of other constituents which may influence the corrosivity, e.g. contamination of O2, H2S etc. If such constituents are present, which is common in e.g. produced water systems, these effects must be evaluated separately.

The model is valid for temperature 5 - 150 °C, pH 3.5 - 6.5, CO2 partial pressure 0.1 - 10 bar and shear stress 1 - 150 Pa. The model is not applicable when the H2S partial pressure is higher than 0.5 bar, or when the ratio between the partial pressure of CO2 and H2S is less than 20. The model can lead to underprediction of the corrosion rate when the total content of organic acids exceeds 100 ppm and the CO2 partial pressure is less than 0.5 bar.

Design principles for material selection and the philosophies which shall apply are given in NORSOK standard M-001 "Material Selection". The requirements in NORSOK M-001 shall always apply, and shall be used when generating input data and when interpreting results from this CO2 corrosion rate calculation program. It is important to note that the program may use or generate data which are outside the limits of NORSOK M-001. One example is corrosion inhibitor efficiency, where NORSOK M-001 provides maximum allowable values, while this program accepts all values from 0 to 100%. In case of conflict, NORSOK M-001 shall apply.

The computer program has a main dialogue box, denoted as the "Main Menu", where all corrosion rate calculations can be performed. All input parameters can be entered into the program directly at this stage for point calculations.

As options and support functions, it is possible to calculate several of the main input parameters by selecting optional dialogue boxes. Such options are:

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SheetHelp

* pH calculations

* shear stress calculations

* humidity calculations for gas systems

These program routines are included in order to make the material selection

specialist able to generate adequate input data for corrosion rate prediction based on data normally presented in process flow diagrams and design basis documents. The support program routines are prepared to give adequate accuracy for corrosion rate calculations, and shall not be used for other purposes, e.g. genuine process, scale or flow calculations.

The program is explained in more detail in NORSOK Standard M-506.

It is important that your computer uses a period as a decimal separator. The program will not be able to calculate correctly if other symbols are used as decimal separator. The decimal separator can be changed from the option called International or Regional and Language Options in the control panel.

Minimum screen resolution must be 600x800.

The current version of the model is Revision 2, issued in June 2005.

It supersedes Revision 1, issued in May 1998. Major changes from Revision 1 are extension of the lower temperature limit from 20 to 5 °C and improved correlations for pH calculation at high pressure and high ionic strength.

Please note that whilst every effort has been made to ensure the accuracy of the NORSOK standards neither OLF nor TBL or any of their members will assume liability for any use thereof.

The effect of inhibitor is given in percent. Allowed range is from 0 to 100 %. The inhibitor efficiency equals the value of the corrosion rate adjusted for the inhibitor effect divided with the corrosion rate without any inhibitor effect multiplied with 100. If no inhibitor effect on the calculation of the corrosion rate is desired, enter 0 % inhibitor efficiency.

RESULTS FUGACITY

The CO2 fugacity will be calculated based on given temperature, pressure and given amount of CO2.

GLYCOL CORRECTION FACTOR

The glycol correction factor will be calculated based on the given glycol

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concentration. The glycol correction factor equals the value of the corrosion rate adjusted for the effect of glycol divided with the corrosion rate without any glycol effect.

CORROSION RATE WITHOUT GLYCOL OR INHIBITOR EFFECT

The calculated corrosion rate without any correction factors will be shown when the button called "Calculate corrosion rate" is pressed.

CORROSION RATE WITH GLYCOL OR INHIBITOR EFFECT

The calculated corrosion rate with correction factor will be shown when the button called "Calculate corrosion rate" is pressed. If the effect of inhibitor is higher than the effect of glycol, the corrosion rate with only the inhibitor effect will be shown. If the effect of glycol is higher than the effect of inhibitor, the corrosion rate with only the glycol effect will be shown. If there is no effect of glycol or inhibitor, only the corrosion rate without any correction factors will be shown.

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MAIN MENU

OPTIONS UNITS

Press the unit buttons to change the unit of temperature, pressure and CO2 partial pressure.

CALCULATE CORROSION RATE

Press this button to calculate the corrosion rate by the NORSOK M-506 model. USE AS INPUT: CO2 PARTIAL PRESSURE OR FUGACITY

Use this option to select partial pressure or fugacity as input. The fugacity of CO2 (calculated if not given as input) is always used in the corrosion model.

CALCULATE SHEAR STRESS

The wall shear stress can be calculated from given liquid and gas velocities. Press this button to enter the menu for calculation of shear stress.

CALCULATE pH

The pH can be calculated from the given bicarbonate concentration. Press this button to enter the menu for calculation of pH.

PARAMETER STUDY

Press this button to get a graphic representation of the corrosion rate as function of the input parameters.

ACCUMULATED CORROSION

Press this button to enter a menu where it is possible to get a time dependent representation of the corrosion rate.

CALCULATE HUMIDITY

The relative humidity can be calculated. Press this button to enter the menu for calculation of relative humidity.

PRINT

Press this button to print the input and output values. SAVE IN NEW FILE

Press this button to save the input and output values in a separate Excel file. The data can either be saved in a new Excel file or a previous saved file can be loaded and then the saved data will be added to this file.

SAVE IN CURRENT FILE

Press this button to save the input and output values in the same file that has been used for saving values before. Values for the same parameters that have been saved in this file before will be saved.

SHOW CURRENT FILE

Press this button to see the data that has been saved in the current file. EXIT

Exit the NORSOK M-506 model.

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INPUT PARAMETERS

PROJECT, EQUIPMENT, IDENTIFIER AND COMMENT

The project name, equipment, identifier and any comments can be given. These names can be saved together with other data when the save buttons are pressed. TEMPERATURE

Allowed range is from 5 °C to 150 °C. The temperature can be given in °C or °F. TOTAL PRESSURE

Allowed range is from 1 bar to 1000 bar. The total pressure can be given in bar or psi. The total pressure must be higher then the CO2 partial pressure.

TOTAL MASS FLOW

Allowed range is from 0.001 to 1000000 kmole/h. The total mass flow is required to calculate the CO2 partial pressure when the amount of CO2 is given in kmole/h. The total mass flow will therefore only be shown in the menu when kmole/h is chosen as the unit for the CO2 amount.

CO2

Allowed range for the fugacity of CO2 is from 0.1 to 10 bar, but the CO2 pressure can not be higher than the given total pressure. Due to lack of data points at fugacities below 0.3 bar, the calculation is uncertain at CO2 fugacities below 0.3 bar.

The amount of CO2 can be given in bar, psi, mole% or kmole/h. It is possible to specify either the CO2 partial pressure or the CO2 fugacity by using the option called

"Use as input: CO2 pressure or CO2 fugacity". SHEAR STRESS

Allowed range is from 1 to 150 Pa. pH

Allowed range: 3.5 to 6.5. GLYCOL CONCENTRATION

The glycol concentration is given in percent. Allowed range is from 0 to 100 %. If you don't want any glycol effect on the calculation of the corrosion rate, just enter 0 % of glycol.

INHIBITOR EFFICIENCY

The effect of inhibitor is given in percent. Allowed range is from 0 to 100 %. The inhibitor efficiency equals the value of the corrosion rate adjusted for the inhibitor effect divided with the corrosion rate without any inhibitor effect multiplied with 100. If no inhibitor effect on the calculation of the corrosion rate is desired, enter 0 % inhibitor efficiency.

RESULTS FUGACITY

The CO2 fugacity will be calculated based on given temperature, pressure and given amount of CO2.

GLYCOL CORRECTION FACTOR

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concentration. The glycol correction factor equals the value of the corrosion rate adjusted for the effect of glycol divided with the corrosion rate without any glycol effect.

CORROSION RATE WITHOUT GLYCOL OR INHIBITOR EFFECT

The calculated corrosion rate without any correction factors will be shown when the button called "Calculate corrosion rate" is pressed.

CORROSION RATE WITH GLYCOL OR INHIBITOR EFFECT

The calculated corrosion rate with correction factor will be shown when the button called "Calculate corrosion rate" is pressed. If the effect of inhibitor is higher than the effect of glycol, the corrosion rate with only the inhibitor effect will be shown. If the effect of glycol is higher than the effect of inhibitor, the corrosion rate with only the glycol effect will be shown. If there is no effect of glycol or inhibitor, only the corrosion rate without any correction factors will be shown.

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THE FLOW MENU

OPTIONS UNITS

Press the unit buttons to change the unit of temperature, pressure, liquid flow, gas flow and viscosity.

CALCULATE

Press this button to calculate the shear stress and flow regime. OK

Press this button to get back to the main menu and use the calculated shear stress in the corrosion rate model.

CANCEL

Press this button to get back to the main menu without using the calculated shear stress. All the values in the flow menu will be restored.

PRINT

SHOW CURRENT FILE

Press this button to see the data that has been saved in the current file.

EXPERT INPUT

Press this button to show the parameters viscosity, density, inversion point, roughness, compressibility and specific gravity. When the user interface starts, default values will be used for these parameters until the user choose to use other values.

DEFAULT CHECK BOXES

There are default check boxes for the density, viscosity, inversion point, roughness, compressibility and specific gravity. When a default option is turned on, a built in function or default value is used for the actual parameter.

INPUT PARAMETERS

The project name, equipment, identifier and any comments can be given. These names can be saved together with other data when the save buttons are pressed. TEMPERATURE

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Allowed range is from 5 °C to 150 °. The temperature can be given in °C or °F. TOTAL PRESSURE

Allowed range is from 1 bar to 1000 bar. The total pressure can be given in bar or psi. LIQUID VELOCITY / LIQUID FLOW

Allowed range is from 0 to 20 m/s. The liquid flow rate can be given as liquid superficial velocity (unit m/s) or liquid flow (unit Sm3/day). Press the unit button to switch between these units. Superficial liquid velocity equals the actual liquid velocity multiplied with the liquid volume fraction.

GAS VELOCITY / GAS FLOW

Allowed range is from 0 to 40 m/s. The gas flow rate can be given as gas superficial velocity (unit m/s) or gas flow (unit millions of Sm3/day). Press the unit button to switch between these units. Superficial gas velocity equals the actual gas velocity multiplied with the liquid volume fraction.

WATERCUT

Allowed range is from 0 to 100 %. The watercut gives the amount of water in the liquid phase.

DIAMETER

The diameter can be any positive number. The calculation of shear stress is requires turbulent flow. This means that the diameter and the flow velocities must be given values that results in a Reynold number above 2300.

DENSITY

The allowed ranges for the density of water, oil and gas are: 995 to 1050 kg/m3 for water density,

600 to 1100 kg/m3 for oil density, 1 to 1700 kg/m3 for gas density. VISCOSITY

The allowed ranges for the viscosity of water, oil and gas are: 0.17 to 1.1 cp for water viscosity,

0.2 to 200 cp for oil viscosity, 0.02 to 0.06 cp for gas viscosity.

The viscosity of water, oil and gas can be given in cp (centipoise) or N*s/m2. ROUGHNESS

Allowed range for the roughness of the steel is 0 to 100 µm. COMPRESSIBILITY

Allowed range is from 0.8 to 1. The compressibility gives the deviation from ideal gas.

SPECIFIC GRAVITY

Allowed range is from 0.5 to 1. INVERSION POINT

Allowed range is from 0.3 to 0.9. The inversion point is the watercut that gives the maximum liquid viscosity.

MAXIMUM RELATIVE LIQUID VISCOSITY

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Allowed range is from 1 to 100. This number gives the ratio between the liquid viscosity at the inversion point and the viscosity of pure oil.

RESULTS SHEAR STRESS

The shear stress will be calculated on basis of the given input values. LIQUID VISCOSITY

The liquid viscosity will be calculated on basis of given input values. The liquid viscosity will only be shown if the button called "Expert input" is pressed and all the input parameters are shown in the flow menu.

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THE PARAMETER STUDY MENU

OPTIONS RETURN

Press this button to get back to the main menu. UPDATE CHART

If you change a value in this menu, the chart will not be updated unless you press the update chart button.

PRINT

Press this button to print the chart as it is shown on the screen. SAVE

Press this button to save the chart and a table with corresponding data in a separate Excel file.

ZOOM BUTTONS

Use these buttons to make the chart on the screen bigger or smaller. CHART TITLE

If the default check box is turned on a default chart title will be used. Otherwise, any chart title may be given.

PARAMETERS

1. VARIABLE PARAMETER

The 1. variable parameter represents the parameter at the x-axis on the chart. Temperature, pH, CO2 partial pressure and shear stress can be chosen as 1. variable parameter. If CO2 is given in mole% the pressure, and not the CO2 partial pressure, can be given as 1. variable parameter.

RANGE VALUES

The minimum and maximum range values represent the minimum and maximum values on the x-axis.

2. VARIABLE PARAMETER

The 2. variable parameter represents the parameter witch is varied in the three lines in the chart. Temperature, pH, CO2 partial pressure and shear stress can be chosen as 2. variable parameter, but the 2. variable parameter can't be equal to the 1. variable parameter. If CO2 is given in mole% the pressure, and not the CO2 partial pressure, can be given as 2. variable parameter.

THE FIRST, SECOND AND THIRD VALUES

These data represent the values of the second parameter in the three different lines in the chart.

OTHER INPUT PARAMETERS See help on main menu. UNITS

It is not possible to change the units in the Parameter study menu. The units will be

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the same as in the Main menu, with exception of the CO2 amount if given as kmole/h. The CO2 amount will then be re-calculated to mole% CO2 in the Parameter Study menu.

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THE ACCUMULATED CORROSION MENU

ACCUMULATED CORROSION

Accumulated corrosion is corrosion given in mm as function of time. Accumulated corrosion in a line in the table shown on the screen is set equal to the accumulated corrosion in the line above plus the calculated corrosion rate in the actual line multiplied with the time difference between the two lines.

OPTIONS CALC pH

Press this button to go to the pH calculation menu. CALC SHEAR

Press this button to go to the shear stress calculation menu. ACC. OFF / ACC. ON

Use this button to switch from accumulated corrosion (given in mm) actual corrosion (given in mm/year).

SHOW CHART / SHOW TABLE

Use this button to switch between a table with the results and a graphic presentation of the results.

INSERT LINE

Use this button to insert a new line with the given input values and a corresponding corrosion rate in the table.

DELETE LINE

Delete the data in the line specified in the menu. CLEAR TABLE

Press this button to delete all the data in the table.

ZOOM BUTTONS

Use these buttons to make the chart on the screen bigger or smaller. RETURN

Press this button to get back to the main menu. The values in the table for accumulated corrosion will be lost if they have not been saved.

PRINT

Prints the data shown at the screen. If the table with data is shown, the table will be printed, and if the chart is shown, the chart will be printed.

SAVE

Save the table with the results. LOAD

Load a previous saved table with accumulated corrosion data and recalculates the table.

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PARAMETERS LINE NUMBER

Allowed range is from 1 to 50. The line number specifies the actual line in the table. If the button called "Insert line" is pressed, the data will be inserted in the line with the specified line number. If the button called "Delete line" is pressed, the data in the specified line number will be deleted.

DATE

Both start date and end date must be specified for each line with data. Dates are entered as month (three letters) - year (four numbers). Example: Feb-1998. OTHER PARAMETERS

See help on main menu. UNITS

It is not possible to change the units in the Accumulated corrosion menu. The units will be the same as in the Main menu.

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THE pH MENU

OPTIONS UNITS

Press the unit buttons to change the unit of bicarbonate, ionic strength, temperature, pressure and amount of CO2.

CALCULATE

Press this button to calculate the pH. CONDENSED / FORMATION WATER

Choose condensed water or formation water. If conduced water is chosen both the bicarbonate concentration and the ionic strength will be set to 0 g/l.

OK

Press this button to get back to the main menu and use the calculated pH in the model.

CANCEL

Press this button to get back to the main menu without using the calculated pH. All the values in this menu will be restored.

PRINT

SHOW CURRENT FILE

INPUT PARAMETERS

The project name, equipment, identifier and any comments can be given. These names can be saved together with other data when the save buttons are pressed. It is not necessary to enter any text to these parameters.

TEMPERATURE

Allowed range is from 5 °C to 150 °C. The temperature can be given in °C or °F. TOTAL PRESSURE

Allowed range is from given CO2 partial pressure to 1000 bar. if the CO2 partial pressure is below 1 bar, the minimum total pressure is 1 bar. The total pressure can be given in bar or psi.

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TOTAL MASS FLOW

Allowed range is from 0.001 to 1000000 kmole/h. The total mass flow is required to calculate the CO2 partial pressure when the amount of CO2 is given in kmole/h. The total mass flow will therefore only be shown in the menu when kmole/h is chosen as the unit for the CO2 amount.

CO2

Allowed range for the fugacity of CO2 is from 0 to 50 bar, but the CO2 pressure can not be higher than the given total pressure. It is possible to specify either the CO2 partial pressure or the CO2 fugacity by using the option called "Use as input: CO2 pressure or CO2 fugacity" in the main menu. The amount of CO2 can also be given in either bar, psi, mole% or kmole/h.

BICARBONATE

Allowed range is from 0 to 20000 mg/l. The concentration of bicarbonate can be given in mg/l or molar. The molecular weight of bicarbonate (HCO3-) is 61.02 g/mole. This means that 1 M bicarbonate equals 61.02 g bicarbonate/l.

IONIC STRENGTH

Allowed range is from 0 to 175 g/l. The ionic strength can be given in g/l or molar. When the ionic strength is given in g/l it is assumed that NaCl is the dominant specie in the solution. The molecular weight of NaCl is 58.44 g/mole. This means that an ionic strength of 1 M equals an ionic strength of 58.44 g/l.

RESULTS pH

The pH will be calculated on basis of the given input values.

For condensed water systems, the pH in a solution saturated with iron carbonate is also calculated.

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THE SAVE MENU

The save menu provides two different alternatives: 1. Save data in a new separate Excel file

2. Load a previous saved Excel file and add saved data to this file

If it is wanted to save data in a new separate Excel file the parameters that are supposed to be saved must be turned on in this save menu. Click the button called "Create new file" when the desired parameters are turned on, and then the program will ask for the file name before the program returns to the previous shown menu. In this case the current data will be saved as the first set of data in the new file. If it is wanted to use a previous saved file to save new data the file can be loaded by pressing the Load button. In such cases it has no meaning to turn on or off any parameters in the save menu because the same parameters that have been saved in the loaded file earlier will still be saved in this file. When a file is loaded in this way the actual parameters will not be saved automatic. The data will only be saved by clicking the buttons called "Save in current file" in the different menus.

Click the Cancel button to return to the previous menu without creating a new file or loading an old file.

THE SHOW MENU

RETURN

Press this button to get back to the previous menu. PRINT

Prints the data shown in the table at the screen. ZOOM BUTTONS

Use these buttons to make the table on the screen bigger or smaller. SCROLL BARS

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THE HUMIDITY MENU 1

OPTIONS CALCULATE

Press this button to calculate the relative humidity and the dew point. OK

Press this button to get back to the main menu. CANCEL

Press this button to get back to the main menu. All the values in this menu will be restored.

PRINT

SHOW CURRENT FILE

INPUT PARAMETERS

The project name, equipment, identifier and any comments can be given. These names can be saved together with other data when the save buttons are pressed. It is not necessary to enter any text to these parameters.

TEMPERATURE

Allowed range is from -16 °C to 200 °C. The temperature can be given in °C or °F. TOTAL PRESSURE

Allowed range is from 1 bar to 500 bar. The total pressure can be given in bar or psi. TOTAL MASS FLOW

Allowed range is from 0.001 to 1000000 kmole/h. WATER MASS FLOW

Allowed range is from 0.001 to 1000000 kmole/h.

RESULTS

RELATIVE HUMIDITY

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The relative humidity given in percent will be calculated on basis of the given input values. The calculated humidity is only valid for pure water, that is water with no glycol. DEW POINT

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NORSOK M-506

NORSOK M-506, CALCULATION OF ACCUMULATED CORROSION

Line

no. Start time End time

Temperatur

e Pressure Total flow CO2

CO2 fugacity Shear Stress pH Glycol conc. Inhibitor efficiency Corrosion rate Accumulated corrosion

Date Date °C bar kmole/h kmole/h bar Pa % % mm/year mm

x

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NORSOK M-506

NORSOK M-506, CALCULATION OF ACCUMULATED CORROSION

Line

no. Start time End time Temperature Pressure CO2

CO2

fugacity

Shear

Stress pH Glycol conc. Inhibitor efficiency Corrosion rate Accumulated corrosion

Date Date °C bar bar bar Pa % % mm/year mm