Solution of Well performance

7/16/2019 Solution of Well performance

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Q#1: Attempt a match by halving the aquifer permeability, and use the program to determine the best matched OGIP.

The best matched OGIP60.19Bscf


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her attempt to quantify the possible OGIP, try using other aquifer models: Fetkter-Tracey, for the base case parameters presented.

Carter-Tracey:

46.82Bscf


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Fetkovich semi steady state


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Question:OGIP in red color ischangeable,The rest of them can notchangeCause these data arefundamentaldata from core andlogging.Am I right?

Are these aquifer data changeable in order to matchhistory data? If changeable, is the outer/inner radius ratithe most important, because I find this parameter is morsensitivity to the simulation result.


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The input basic data

tched very well, but the basic data changed, tank porosity: 0.07,51.7Bcf, far away from the data required in the title.

r match, but the basic data did not change, GIP=65.08bcf(close to the data reqe title).


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Permeability changefrom

1200mdto 600md,the rest ofthem arethe same


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May 10, 2013


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Carter- tracey radius 40


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Carter- tracey radius 48.8


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GIIP = 57.7 Bcf


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GIIP = 61.7 Bcf


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GIIP = 65.1 Bcf


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Halving the permeability


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New one since May 13 after discussion with leo


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57.7 58.5609, 63452.9


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aving permeability ( 1200-600md)

HavitheShutAssoGasAlso,The110TherRigh


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Fetkovich (65.1) 63.0952, 31794.7


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Gas in place


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Aquifer volume


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Reservoir width, reasonable


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Reservoir thickness


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Aquifer permeability, not very well


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Fetkovich (61.7)

63.1309, 31794.7

As a further attempt to quantify the possible OGIP try using other aquifer


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cording the two matching process of Fetkovich Semi Steady State Linear,e acquifer permeability is more sensitive than other parameters.

orover, from the sensitivity analysis, deviation for other parameters are bighich means that this parameters are not so accurate or this model is not

ell for this kind of aquifer.

quifer volume is 178.424Bft3 and the total pore volume is only 0.528Bfts,omparison of aquifer and total pore volume of reservoir, the property of aquifervoir seems to infinite, this is the reason that fetkovich can not be used in thisfer, and moreover result in the parameters in big deviation in probability distrib

As a further attempt to quantify the possible OGIP, try using other aquifermodels:Fetkovich and Carter-Tracey, for the base case parameters presented. What aryour conclusions?In this case, how reasonable is it to use the Fetkovich formulation?


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Carter-Tracey(48.8)

Aquifer permeability, not best one

46.6058


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Gas in place, not best one


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Reservoir radius, best one


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Reservoir thickness, best one


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Carter-Tracey(40.0)

Aquifer permeability, not the best one

46.6138, 35511.9


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Gas in place, not the best data


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Reservoir radius, reasonable


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Encroachment angle, reasonable


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Reservoir thickness, reasonable


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In addition to matching pressures (using the given production


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In addition to matching pressures (using the given productionhistory), how well are you matching the contact rise? Assume variousresidual gas saturations and comment on the results.

erent residual gas saturations in reservoir will definitely affect the depth of GWause production is determined by the history data, higher Sgr in reservoir resule volume swept by water, and lead to higher GWC.


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GWC is 1184m ss in 1998-03, and 1165m ss 2000-11.

Fetkovich semi steady state linear model, GWC can match 1184mss very wellual gas saturation is between 0.50 and 0.55, but it can not match the real GWC0.redial model has the similar result, it can match 1184mss very well while residn is around 0.5, but it can not match the real GWC of Nov., 2000 very well even

Carter-tracey radial model, it can match 1184mss very well while the residual0.4, and match 1165mss while the residual gas is approximately 0.5.

, all the parameters in above table are assumed with 100% water sweep efficie, 100% water sweep efficiency can not true.


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Could you also vary the volumetric sweep efficiency and obtain similarresults? Try out this option and comment on results obtained.

se the Fetkovich model does not fit for this specific case due to the infinite aquistength, the dake model is the only model can be considered in this case.

llowing is to figure out the water sweep efficiency in order to match the historiery well.

sweep efficiency will change the water influx volume in reservoir under the sa

tion and also the GWC.water sweep efficiency will need more water influx volume in reservoir in orderthe historical production data than higher water sweep assumed that Sgr is det


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he water sweep efficincy is 80%, the depth of GWCs in all the model are lower

e ones while WSE is 100%.e Fetkovich semi steady state linear model, GWC can match 1184mss very welidual gas saturation is approximately 0.45, but it can not match the real GWC o00 very well even the Sgr is 0.55.e Dake radial model, GWC can match 1184mss very well whileidual gas saturation is 0.45-0.40, and it can also match the real GWC of

00 while Sgr is 0.50-0.55.

e Carter-Tracey model, GWC can match 1184mss very well whileidual gas saturation is 0.25-0.35, and it can also match the real GWC of00 while Sgr is 0.40-0.45. However, residual gas saturation is approximately 0% water sweep efficiency is not logical in real field data. Therefore, this model

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Solution of Well performance

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