__TOC__
==Brief==
The most common formula used for multiphase flow through surface chokes by Gilbert <ref name=Gilbert/><ref name=KermitBrown1984/>.

Gilbert developed his empirical equation from field data in California.

==Math and Physics==
:<math>P_{wh}=\frac{435 \times GLR^{0.546}}{D^{1.89}} \times q</math>

Note that the equation is independent of the downstream pressure and assumes that the downstream pressure is less than 70% of the upstream pressure, i.e. the flow is "critical" and fluid reach sonic velocity in the throat of the choke.

==Example==
===Given data===
Oil rate = 600 bbl/d, GLR=400 scf/bbl, D=22/64 in, Line pressure = 180 psia

Calculate the well head pressure?

===Solution===
:<math>P_{wh}=\frac{435 \times 0.4^{0.546}}{22^{1.89}} \times 600 = 460 psig or 460 +14.7 = 474.7 psia</math>

Validity check 180/460=0.4 < 0.7 OK

==Nomenclature==
:<math>D</math> = choke beam diametr, 64th of an inch
:<math>GLR</math> = gas liquid ratio, Mscf/bbl or 10^3 scf/bbl
:<math>P_{wh}</math> = well head pressure, psig
:<math>q</math> = flow rate, bbl/d

== References ==
<references>
<ref name= Gilbert>{{cite book
|last1= Gilbert |first1= W.E.
|title=Flowing and Gas-Lift Well Performance
|journal=Drilling and Production Practice API
|date=1954
|page=143
}}</ref>
<ref name= KermitBrown1984 >{{cite book
|last1= Brown |first1= Kermit
|title=The Technology of Artificial Lift Methods. Volume 4. Production Optimization of Oil and Gas Wells by Nodal System Analysis
|publisher=PennWellBookss
|date=1984
|place=Tulsa, Oklahoma
}}</ref>

</references>

{{#seo:
|title=Gilbert choke equation
|titlemode= replace
|keywords=Gilbert choke equation
|description=Gilbert choke equation
}}

[[Category:Technology]]

2024-11-08T15:22:13Z

MishaT: Created page with "__TOC__ ==Brief== The most common used formula for multiphase flow through surface chokes by Gilbert <ref name=KermitBrown1984/>. Echometer is used to measure the fluid level..."

__TOC__
==Brief==
The most common used formula for multiphase flow through surface chokes by Gilbert <ref name=KermitBrown1984/>.

Echometer is used to measure the fluid level in the wells.

Fluid level is used to calculate and monitor the bottom hole pressure of the wells.

==Math and Physics==
The physics is based on the principal hydrostatics law:
:<math>P=\frac{\rho g h}{101325}</math>

===Flowing well fluids segregation===
When the well is flowing with the pump this is how fluids segregate in the well bore:
*Oil, gas and water are produced through the tubing from the reservoir to the surface
*Gas is in the annulus from the surface to the fluid level, Hd
*Oil and gas are between the fluid level Hd, and the pump setting depth, Hd
*Water, oil and gas are between pump, Hd and the top of the perforations, Hperfs
*Water is in the rathole

===Equation to calculate the BHP from the fluid level===
:<math>P_{wf}=P_{ann}+\frac{(H_{perfs}-H_{pump})(SG_o(1-WCUT)+SG_w WCUT)+(H_{pump}-H_d)SG_o}{10.32}</math>

Note that for the deviated wells TVD depths should be used.

==Nomenclature==
:<math>g</math> = 9.81, m/s^2
:<math>h</math> = depth, m
:<math>H_d</math> = fluid level, m
:<math>H_{perfs}</math> = top of the perforations, m
:<math>H_{pump}</math> = pump setting depth, m
:<math>P</math> = pressure, atm
:<math>P_{ann}</math> = annulus presssure, atm
:<math>P_{wf}</math> = well flowing bottomhole pressure, atm
:<math>\rho</math> = density, kg/m^3
:<math>SG_o</math> = oil specific gravity, dimensionless
:<math>SG_w</math> = water specific gravity, dimensionless
:<math>WCUT</math> = well water cut, fraction

== References ==
<references>
<ref name= KermitBrown1984 >{{cite book
|last1= Brown |first1= Kermit
|title=The Technology of Artificial Lift Methods. Volume 4. Production Optimization of Oil and Gas Wells by Nodal System Analysis
|publisher=PennWellBookss
|date=1984
|place=Tulsa, Oklahoma
}}</ref>

</references>

{{#seo:
|title=Gilbert choke equation
|titlemode= replace
|keywords=Gilbert choke equation
|description=Gilbert choke equation
}}

[[Category:Technology]]

Category:PQplot

2024-05-10T07:10:24Z

MishaT: /* Typical applications */

__TOC__
== Well Nodal Analysis Software ==

[[File:PQPLOT_i.png|thumb|300px|link=https://www.pengtools.com/pqPlot| PQplot nodal analysis software]]

[[:Category:PQplot | PQplot software]] is the core '''petroleum engineering''' engine of the [[:Category: Pengtools | pengtools]].

[[:Category:PQplot | PQplot software]] calculates inflow performance relationship [[IPR]] and vertical lift performance [[VLP]] curves for oil and gas wells.

[[:Category:PQplot | PQplot software]] is available online at [https://www.pengtools.com www.pengtools.com].

== Typical applications ==

* Calculating the [[Well Nodal Analysis]] <ref name= JM8025/> model of the well
* Matching the [[Well Nodal Analysis]] model to the well test data
* Calculating and exporting the [[IPR]] curves: [[Vogel's IPR]], [[Composite IPR]]
* Calculating and exporting the [[VLP]] tables to Excel or reservoir simulator
* Estimation of well's [[Production Potential]] and absolute open flow (AOF)
* Tubing sizing
* Gas lift design
* Selection of the operating wellhead pressures
* Estimation of the effects of reservoir pressure depletion
* Sensitivity studies

== Main features ==
* Multiphase flow correlations
* Plot of Inflow performance curve [[IPR]] and Vertical lift performance curve [[VLP]]
* Rate and pressure at intersection point
* Tubing, annular and tubing+annular flow types
* "Default values" button resets input values to the default values
* Switch between Metric and Field units
* Save/load models to the files and to the user’s cloud
* Share models to the public cloud or by using model’s link
* Export pdf report containing input parameters, calculated values and plots of the PQplot
* Continue your work from where you stopped: last saved model will be automatically opened
* Download the chart as an image or data and print (upper-right corner chart’s button)
* Export results table to Excel or other application

==Demo==
The demo is a copy of a training seminar. This video demonstrates basic functionality of the [[:Category:PVT | PVT Software]] and [[:Category:PQplot | PQplot software]]. It is shown how to create the well nodal analysis model, run sensitivity, save the model.

[[File:PQplot_demo.png|400px|link=https://youtu.be/oioheTV45tU | Watch on youtube]]

In this demo we are solving the homework where it was asked to:
* Calculate the flowing bottomhole pressure.
* Construct [[VLP]] curve
* Construct [[IPR]] and calculate AOF
* Calculate current production efficiency (production/AOF)
* What is the production potential and what actions do you propose to close the performance gap?
* What will be production increment from the proposed actions?

[https://www.pengtools.com/pvtCalculator?paramsToken=b4bd505e0a17a75adb14f0989f89c502 PVT model at www.pengtools.com]<BR/>
[https://www.pengtools.com/pqPlot?paramsToken=9fba6c3fa125c5e6d8aa101e5cf9b52c PQplot model at www.pengtools.com]

== Correlations ==

<table width="100%" border="1" cellpadding="3" cellspacing="1">
<tr>
<th>Type of problem</th>
<th>Correlation</th>
<th>Reference</th>
</tr>

<tr><td>
Oil well [[VLP]]
</td><td>
[[Hagedorn and Brown correlation|Hagedorn and Brown]] + [[Griffith correlation| Griffith]]
</td><td>
Hagedorn, A. R., & Brown, K. E. (1965). Experimental study of pressure gradients occurring during continuous two-phase flow in small-diameter vertical conduits. Journal of Petroleum Technology, 17(04), 475-484.
</td></tr>
<tr><td>
Gas well [[VLP]]
</td><td>
[[Gray correlation|Gray]]
</td><td>
Gray, H. E. (1974). Vertical flow correlation in gas wells. User manual for API14B, subsurface controlled safety valve sizing computer program.
</td></tr>
<tr><td>
Dry gas [[VLP]]
</td><td>
[[Fanning correlation|Fanning]]
</td><td>
Cullender, M.H. and Smith, R.V. 1956. Practical Solution of Gas-Flow Equations for Wells and Pipelines with Large Temperature Gradients. Trans., AIME 207: 281.
</td></tr>
<tr><td>
Oil well [[IPR]]
</td><td>
[[Composite IPR]] – [[Vogel's IPR]] based equations taking into account water
</td><td>
Kermit E. Brown "The Technology of Artificial Lift
Methods" Vol. 4 Production Optimization of Oil and Gas
Wells by Nodal System Analysis, p. 30, section 2.227.1
</td></tr>
<tr><td>
Gas well [[IPR]] – backpressure equation
</td><td>
Rawlins and Schellhardt
</td><td>
Rawlins, E.L. and Schellhardt, M.A. 1935. Backpressure Data on Natural Gas Wells and Their Application to Production Practices, Vol. 7. Monograph Series, USBM.
</td></tr>
<tr><td>
Gas well [[IPR]] – pseudo-pressure equation using Jd and kh values
</td><td>
Real-gas pseudopressure equation
</td><td>
See for example: Ahmed, T., & McKinney, P. (2011). Advanced reservoir engineering. Gulf Professional Publishing.
</td></tr>
<tr><td>
[[Liquid loading]]
</td><td>
Turner
</td><td>
Turner, R. G., Hubbard, M. G., and Dukler, A. E. (1969) “Analysis and Prediction of Minimum Flow Rate for the Continuous Removal of Liquids from Gas Wells,” Journal of Petroleum Technology, Nov. 1969. pp. 1475–1482.
</td></tr>
<tr><td>
[[Erosional velocity]]
</td><td>
Guidelines from API RP14E
</td><td>
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.
</td></tr>
</table>

PVT correlations are the same as in [[:Category:PVT|PVT software]].

== References ==
<references>
<ref name=JM8025>{{cite journal
|last1=Mach|first1=Joe
|last2=Proano|first2=Eduardo
|last3=E. Brown|first3=Kermit
|title=A Nodal Approach For Applying Systems Analysis To The Flowing And Artificial Lift Oil Or Gas Well
|publisher=Society of Petroleum Engineers
|number=SPE-8025-MS
|date=1979
|url=https://www.onepetro.org/general/SPE-8025-MS
|url-access=registration
}}</ref>

</references>

[[Category:pengtools]]

{{#seo:
|title=Well Nodal Analysis Software
|titlemode= replace
|keywords=nodal analysis, nodal analysis software, tubing, reservoir, fluids flow, sensitivity, gas flow, petroleum engineering
|description=PQplot petroleum engineering software calculates inflow performance relationship and vertical lift performance curves for oil and gas flow for well nodal analysis.
}}