Difference between revisions of "Can Of Beans (Gas)"

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(Math and Physics)
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And V<sub>2</sub> > V<sub>1</sub> because P<sub>2</sub> < P<sub>1</sub>. The lower the P<sub>2</sub> gets over P<sub>1</sub> the higher the incremental recovery will be.
 
And V<sub>2</sub> > V<sub>1</sub> because P<sub>2</sub> < P<sub>1</sub>. The lower the P<sub>2</sub> gets over P<sub>1</sub> the higher the incremental recovery will be.
  
==Well Nodal Analysis Example==
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==Summary==
Given data<ref name=JoeMach/>:
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Produce gas reservoirs fast to increases recoveries.
SG<sub>g</sub>=0.65, SG<sub>o</sub>=35 API, P<sub>r</sub>=2200 psi, P<sub>b</sub>=1800 psi, T<sub>r</sub>=140 F, depth = 5000ft, tubing size = 2 3/8 in OD, GOR=400 scf/stb, WOR=0
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If you have an aquifer you have to produce fast.
Productivity index J = 1 bbl/d/psi
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If you don’t have an aquifer…, so you don’t have water to complain.
  
It's required to find the well flowing rate at the wellhead pressure of 230 psi. Surface flow line and separator are not in question.
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==Video==
===Solution at bottom of well ===
 
In order to solve for the flow rate at bottomhole (node position 6), the entire system  is divided into two components, the reservoir or well capability component, [[IPR]] and the piping system component, [[VLP]] <ref name= KermitBrown1984/>.
 
 
 
:First, [[Vogel's IPR | Vogel's equation]] is used to calculate the [[IPR]] curve. The AOF = 1400 bbl/d
 
 
 
<table border="1" cellpadding="3" cellspacing="1">
 
<tr><th>Rate, bbl/d</th><th>Pwf, psi</th></tr>
 
<tr><td>0</td><td>2200</td></tr>
 
<tr><td>200</td><td>2000</td></tr>
 
<tr><td>400</td><td>1800</td></tr>
 
<tr><td>600</td><td>1590</td></tr>
 
<tr><td>800</td><td>1350</td></tr>
 
<tr><td>1000</td><td>1067</td></tr>
 
<tr><td>1400</td><td>0</td></tr>
 
</table>
 
 
 
 
 
:Second, [[Hagedorn and Brown]] multiphase flow correlation is used to calculate the required tubing intake pressures at the given wellhead pressure, [[VLP]] curve.
 
 
 
<table border="1" cellpadding="3" cellspacing="1">
 
<tr><th>Rate, bbl/d</th><th>Pwf, psi</th></tr>
 
<tr><td>0</td><td>1929</td></tr>
 
<tr><td>200</td><td>1065</td></tr>
 
<tr><td>400</td><td>1125</td></tr>
 
<tr><td>600</td><td>1181</td></tr>
 
<tr><td>800</td><td>1235</td></tr>
 
<tr><td>1000</td><td>1289</td></tr>
 
<tr><td>1400</td><td>1399</td></tr>
 
</table>
 
 
 
 
 
:Third, [[IPR]] and [[VLP]] curves are plotted on the pressure vs rate plot. The intersection of these two curves shows the flow rate to be 872 bbl/d.
 
 
 
[[File:Well Nodal Analysis Example.png | link=https://www.pengtools.com/pqPlot?paramsToken=7db370789c234c0949337f8b1978fa3c | Solution at Bottom of Well]]
 
 
 
{{Quote| text = This is "the rate" possible for this system. It is not a maximum, minimum, or optimum but is the rate at which this well will produce for the piping system installed. The rate can be changed only by changing something in the system - that is, pipe sizes, choke or by shifting the [[IPR]] curve through simulation treatment. | source = Kermit Brown et al <ref name= KermitBrown1984/>}}
 
  
 
== See also ==
 
== See also ==

Revision as of 08:07, 12 December 2022

Brief

If you eat the can of beans fast then the can doesn’t last as long as if you eat it slow, but you still eat the same amount of beans.

A case study on how to increase the gas recovery factor by increasing the gas production rates.

Have you ever heard that if you increase the choke size on a gas well, the well will "die" soon, because of the water? And gas recovery will go down too?

What if you could increase the gas production and recover more gas instead?

This case study clearly demonstrates that gas recovery is increased with increasing the gas rate.

It is shown that enhanced well will add more reserves then non-enhanced well.

Case study is done using the simulation model assuring physics is well governed.

Can of beans analogy

If you eat the can of beans fast then the can doesn’t last as long as if you eat it slow, but you still eat the same amount of beans.

Same logic is true for the gas reservoir with the bottom water.

There is a fixed volume of gas above the water.  When you remove the gas the water moves up. You can do it slow or fast but the volume of gas above the water is the same. The water level will raise Gravity stable as defined by Newton’s Law.

Simulation Runs

Now let's attach the infinite aquifer to the can of gas and run scenarios:

  1. Slow - choked gas rate
  2. Fast - 2x enhanced gas rate

Slow Fast

Oh no, water killed the well quick in the "Fast" case! We told you what! Right, but … which case produced more gas?

Gas Recovery

Gas Recovery Results

12% more recovery with the enhanced production over 20 years. Why?

Because of the pressure! The lower the reservoir pressure the more gas is produced before the water hits the perfs. It’s just physics!

Reservoir Pressure

Math and Physics

According to the Boyle's law (1662):

 PV = constant

where P is pressure, V is volume.

In our case

 PV = constant = P_1V_1 = P_2V_2=P_{res}V_{res}

The gas produced volume of the "Slow case"

 V_1 = \frac{P_{res}V_{res}}{P_1}

The gas produced volume of the "Fast case"

 V_2 = \frac{P_{res}V_{res}}{P_2}

And V2 > V1 because P2 < P1. The lower the P2 gets over P1 the higher the incremental recovery will be.

Summary

Produce gas reservoirs fast to increases recoveries. If you have an aquifer you have to produce fast. If you don’t have an aquifer…, so you don’t have water to complain.

Video

See also

References

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