401re information to your updtgsrhg0829.ppt

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1. HanaBaarová
Technical University in Liberec, Czech Republic

2. 1.Introduction
•Purpose of well testing
2. Radial Homogeneous Flow Model
•Assumptions
•Log-log diagnostic plot
•Semi log diagnostic plot
•Methods to obtain permeability (k), transmissivity(kh) and total skin
3. Radial Composite Flow Model
•Scheme and assumptions
•Acidization, gas fingering, moving water front
•Log-log diagnostic plot
•Semi log diagnostic plot
4. Dietz Correction Shape Factor
•Assumptions
•Cartesian plot –irregular drainage area, position of the well
•Improvement in deliverability calculation
5. Conclusions

3. 1. Introduction -Well testing workflow
Pressure transient analysis data (isochronal pumping test)
Transient data (build-ups)
Early time data(ETD)-wellbore storage coefficient
Middle time data(MTD)–flowmodel to getpermeability (k)and total skin (St)
Late time data(LTD)–boundarymodel to estimateboundary condition
Deliverability –semi theoretical derivation of absolute open flow potential (AOF)
Flowing periods (drawdowns)
non-Darcy skin analysis -true skin (S)and rate-dependent skin(Sd)
Deliverability -LIT analysis to get AOF
www.
goexpro.com
ETD
MTD
LTDFlowmodel
Boundary
model
Log-log diagnosticplot Test overview

4. Wellborestorage
effect Decayofwellbore
storageeffect
Radialhomogeneous
flowregime
Heterogeneity?
2. RadialHomogeneousFlowModel
Cylindrical homogeneous reservoir with well situated in the middle
Results
Forthelayer: k, kh, p
i
Forthewell: s, Cs, Cd
www.
fekete.com
Log-log plot ofthelast buildup
Semilog plot(Radialflowplot) ofthelast buildup
Slopeofthestraight
line m
Lowerk
Zeroslopeline
Test overview
Last buidup

5. •Distance to the radialdiscontinuity
3. RadialCompositeFlowModel
Innerandouterregion
Dueto acidization
Changein gassaturation: gasfingering, movingwaterfront
Steam front, CO
2
miscible flooding front
Innerzone
radialflow
Outerzone
radialflow
•Mobility Ratio
•StorativityRatio
Decreasein
transmissivity
www.siam.org
www.fekete.com
(Not a double slope)
Shortduration
ofWBS
Mobility ratio,
Pseudoradialskin,
Distance Lrad
Lrad

6. 4. DietzCorrectionShapeFactorC
A
Layerparameter, default value31.62
Accountsfor the drainage area shape and the wellposition
BettercalculationofAOF transient, closedsystem
ImprovedAOF Trans
153 840 m
3
/hAOF Trans 165 063 m/h
3
AOF Lit 154 998 m
3
/h
Default C
A = 31.62
C
A = 2.3473
C
A estimatedfromthe
Cartesianplot ofthe
extendeddrawdown

7. 5. Conclusions
Well showing such a change in
transmissivity in log-log plot
Radial composite model
helpful (M, Lrad, ω, k
2)
Acidization
Gas fingering effect
Moving water front
AOF´s from transient flow and
drawdown´snot coherent
Irregulardrainageareashape
Dietz shape factor for closed
system
(low permeable wells only)
Innerzone
radialflow
Outerzone
radialflow