Difference between revisions of "Erosional velocity"

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One can relate [[Erosional velocity]] to a metal loss rate (see RP O501).
 
One can relate [[Erosional velocity]] to a metal loss rate (see RP O501).
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== Nomenclature  ==
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:<math> C </math> = empirical constant, lb/s/ft2
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:<math> J_D </math> = dimensionless productivity index, dimensionless
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:<math> kh</math> = permeability times thickness, md*ft
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:<math> \bar{P} </math> = average reservoir pressure, psia
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:<math> P_{\bar{P}} </math> = average reservoir pseudopressure, psia<sup>2</sup>/cP
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:<math> P_{wf} </math> = well flowing pressure, psia
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:<math> P_{P_{wf}} </math> = average well flowing pseudopressure, psia<sup>2</sup>/cP
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:<math> q </math> = flowing rate, stb/d
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:<math> q_g </math> = gas rate, MMscfd
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:<math> T </math> = temperature, °R
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===Greek symbols===
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:<math> \rho </math> = gas density, lb/ft3
  
 
== References ==
 
== References ==

Revision as of 07:52, 27 April 2020

Erosional velocity

Erosional velocity is a velocity of the multiphase flow at which pipe erosion occurs.

Erosional velocity equation

Pipe erosion begins when velocity exceeds the value of

v=\frac{C}{\sqrt{\rho}}

C/SQRT(ρ) in ft/s, where ρ = gas density (in lb/ft3) and C = empirical constant (in lb/s/ft2) (starting erosional velocity). We used C=100 as API RP 14E (1984) suggested C=100 for continuous and 125 for non continuous service.

This is the empirical relationships for estimating whether erosion will occur in a system at a certain velocity used at PQplot.


Erosion

Erosion is normally expressed as a rate of metal loss, usually mm/year. It usually occurs in turns or protrusions; or with solids content.

One can relate Erosional velocity to a metal loss rate (see RP O501).

Nomenclature

 C = empirical constant, lb/s/ft2
 J_D = dimensionless productivity index, dimensionless
 kh = permeability times thickness, md*ft
 \bar{P} = average reservoir pressure, psia
 P_{\bar{P}} = average reservoir pseudopressure, psia2/cP
 P_{wf} = well flowing pressure, psia
 P_{P_{wf}} = average well flowing pseudopressure, psia2/cP
 q = flowing rate, stb/d
 q_g = gas rate, MMscfd
 T = temperature, °R

Greek symbols

 \rho = gas density, lb/ft3

References

  • Mokhatab S, Poe WA, Speight JG (2006) "Handbook of Natural Gas Transmission and Processing", Section 11.6 - Design Considerations on sales gas pipelines, subsection 11.6.1 - Line Sizing Criteria, Elsevier, 2006.