Difference between revisions of "Erosional velocity"
Line 17: | Line 17: | ||
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). | ||
+ | |||
+ | == Nomenclature == | ||
+ | :<math> C </math> = empirical constant, lb/s/ft2 | ||
+ | :<math> J_D </math> = dimensionless productivity index, dimensionless | ||
+ | :<math> kh</math> = permeability times thickness, md*ft | ||
+ | :<math> \bar{P} </math> = average reservoir pressure, psia | ||
+ | :<math> P_{\bar{P}} </math> = average reservoir pseudopressure, psia<sup>2</sup>/cP | ||
+ | :<math> P_{wf} </math> = well flowing pressure, psia | ||
+ | :<math> P_{P_{wf}} </math> = average well flowing pseudopressure, psia<sup>2</sup>/cP | ||
+ | :<math> q </math> = flowing rate, stb/d | ||
+ | :<math> q_g </math> = gas rate, MMscfd | ||
+ | :<math> T </math> = temperature, °R | ||
+ | |||
+ | ===Greek symbols=== | ||
+ | :<math> \rho </math> = gas density, lb/ft3 | ||
== References == | == References == |
Revision as of 07:52, 27 April 2020
Contents
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
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
- = empirical constant, lb/s/ft2
- = dimensionless productivity index, dimensionless
- = permeability times thickness, md*ft
- = average reservoir pressure, psia
- = average reservoir pseudopressure, psia2/cP
- = well flowing pressure, psia
- = average well flowing pseudopressure, psia2/cP
- = flowing rate, stb/d
- = gas rate, MMscfd
- = temperature, °R
Greek symbols
- = 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.