Well Test analysis interpretation

Well Test Analysis, Pressure and Production Monitoring........ etc.

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soman703
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Well Test analysis interpretation

Post by soman703 »

Hello everyone.

I have this well test derivavtive available and its matched

I found it to be Wellbore storage and skin and later on radial flow and later on I am not sure what it is.

Can anyone help me with detailed Interpretation of this test and how do I deal with such scattered data?

Thankyou,
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FANARCO
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Re: Well Test analysis interpretation

Post by FANARCO »

From these charts it looks gas well.

Is this real test data or test design as in pic number 4
soman703
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Re: Well Test analysis interpretation

Post by soman703 »

I think its real test data.

what do you make of middle time and late time regime in log log derivative plot i.e., last one?
Also how did you conclude it to be gas well? Is it because of sharp WBS & Skin effect visible in horner?
Can I also observe it in this derivative? I might have to interpret such plots in one week in exam haha.pls give any inputs u can.
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Re: Well Test analysis interpretation

Post by FANARCO »

soman703 wrote:I think its real test data.

what do you make of middle time and late time regime in log log derivative plot i.e., last one?
Also how did you conclude it to be gas well? Is it because of sharp WBS & Skin effect visible in horner?
Can I also observe it in this derivative? I might have to interpret such plots in one week in exam haha.pls give any inputs u can.

In the 4th pic it shown a gas flow rate versus time, so looks like gas well.

Actually, the pressure data is not realistic and the build up is not in standard shape. So, you cannot calculate the well bore storage.

The initial time region in the build up increased suddenly and reversed again may be the shut in is done by downhole shut in valve then opened again and they shut in from surface.

What can you do is to use any well test software is to estimate roughly the permeability in a stabilized data on Horner plot and derivatives.
soman703
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Re: Well Test analysis interpretation

Post by soman703 »

Thankyou so much bro.

I will do that.
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Re: Well Test analysis interpretation

Post by anindaghosh2207 »

Initial hump on log log plot is indicating liquid efflux in the well. It means well is taking back the water into the reservoir duing shut in condition. This is very typical syndrome of gas well producing with water. At the end derivative is shooting up. I dont know the slope but from my personal experience it seemed that reservoir is closed from 3 sides.
check you geological model
Aninda Ghosh
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Re: Well Test analysis interpretation

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anindaghosh2207 wrote:Initial hump on log log plot is indicating liquid efflux in the well. It means well is taking back the water into the reservoir duing shut in condition. This is very typical syndrome of gas well producing with water. At the end derivative is shooting up. I dont know the slope but from my personal experience it seemed that reservoir is closed from 3 sides.
check you geological model
Last pic log log on derivative indicating that closed system.

For gas humping i think it is in high GOR wells.

Thanx for explanation
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Re: Well Test analysis interpretation

Post by anindaghosh2207 »

I beg to differ with you.

1. In all the plot it is pseudo pressure (m(p)) vs time. It indicates the well is gas well not oil. Therefore It may not be High GOR well. It is gas well producing with water.

2. In case of closed system the slope of derivative should be +1 in drawdown study. But in case of Build Up if pseudosteady state arrives (Closed System) derivative should fall. This is typically happend due to superimposition principle. That is why we go for deconvolution. Build Up in some case, just like this is misleading. All the plot belongs to Build Up study. I believe straight way indicating Closed system would not be correct.

PLease do correct me if I'm wrong.

Regards,
Thank you
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Re: Well Test analysis interpretation

Post by FANARCO »

1- i mean in high gor has the same phenomena which this case behave like high gor.

2- for boundaries i need to refer to partially closed which is bounded by faults or pinch out...
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