You must log in to edit PetroWiki. Help with editing
Content of PetroWiki is intended for personal use only and to supplement, not replace, engineering judgment. SPE disclaims any and all liability for your use of such content. More information
Message: PetroWiki content is moving to OnePetro! Please note that all projects need to be complete by November 1, 2024, to ensure a smooth transition. Online editing will be turned off on this date.
Simplified mathematical gas lift performance model
The following equations have been proposed as a simplified means of evaluating gas lift performance.
Calculation of GLV stem movement
....................(1)
where
....................(2)
and
....................(3)
Calculation of equivalent port area open to gas flow
....................(4)
where
....................(5)
....................(6)
....................(7)
and
....................(8)
If A Ape > Ap , then Ape = Ap (fixed-ID orifice flow).
Calculation of gas rate through Ape
....................(9)
where
....................(10)
If Rdu < = 0.553, then Rdu = 0.553 (critical flow).
Nomenclature
| Ab | = | effective area of bellows, in.2 |
| Ap | = | valve port area (ball/seat-line contact area for sharp-edged seat), in.2 |
| Ape | = | valve port equivalent area open to gas flow, in.2 |
| Blr | = | bellows-assembly load rate, psi/in. |
| Bsr | = | bellows-assembly spring rate, lbf/in. |
| CT | = | temperature correction factor for nitrogen from PbvD at TvuD to Pb at 60°F, dimensionless |
| Mvs | = | movement of the gas lift valve stem, in. |
| Patm | = | atmospheric pressure, psia |
| PbvD | = | nitrogen-charged bellows pressure at valve temperature, psig |
| PioD | = | injection-gas pressure at valve depth, psig |
| PptD | = | flowing-production transfer pressure at valve depth, psig |
| Pvo | = | test-rack valve opening pressure at 60°F, psig |
| qgi | = | daily injection-gas rate through gas lift valve, Mscf/D |
| rb | = | radius of ball on gas lift valve stem, in. |
| rp | = | radius of valve port (ball/seat-line contact for sharp-edged seat), in. |
| rtf | = | top radius of frustum of right circular cone, in. |
| Rdu | = | ratio of downstream pressure/upstream pressure, psia |
| s | = | slant height of frustum of right circular cone, in. |
| TgiD | = | injection-gas temperature at valve depth, °F |
References
Use this section for citation of items referenced in the text to show your sources. [The sources should be available to the reader, i.e., not an internal company document.]
Noteworthy papers in OnePetro
Use this section to list papers in OnePetro that a reader who wants to learn more should definitely read
External links
Use this section to provide links to relevant material on websites other than PetroWiki and OnePetro
See also
Gas lift installation design methods
Intermittent-flow gas lift installation design