Petroleum Engineering. WELL TEST: ANALYSIS AND DESIGN

Well test was carried out on a well completed in an oil reservoir with the properties listed in table 1. The schedule consisted of a short clean-up period followed by a build-up period (first build up), constant rate production for approximately 24 hours and a 48 hour build up period (second build up).20 

Files 

1. Pressuredata:Pressuredata.txt 

2. Rate data: Ratedata.txt
Import pressure data in excel and identify first build up, production and second build up. 

Tasks 1, 2 and 3, must be carried out manually. 

Task 1: Reservoir properties from first build up 

1. Forthefirstpressurebuildupdata,constructanequivalenttimecurve 2. Calculatepermeability,skinandinitialpressure 

Task 2: Reservoir properties from production data 

1. Forthesustained24hourproductiondata,constructasemiloggraphofpressurevstime. 2. Calculatepermeability,skinandwellborestorage. 

Task 3: Reservoir properties from second build up 

1. Forthesecondbuilduptestdata,constructalog-loggraphofpressurevstimeandderivativeofpressure vs time.
   • UseexcelorKappatogeneratepressurederivativevstimecurveonlog-logscale.
    
2. Calculatepermeability,skinandwellborestoragebyBourdet’stypecurvematch
    
3. Identify boundary
    

Task 4: Reservoir properties from Kappa Saphir 

1. Calculatereservoirpermeability,skinandwellborestorageforfirstbuildup,productionandsecondbuild- up
    
2. Identify boundary
    
3. Performsensitivityanalysisforvariationofskin,wellborestorageandpermeability
    

1 

Report 

The objective of this exercise is to compare the quality of the data generated through various methods: semilog analysis of pressure drawdown and buildup, type curve matching and through use of software. The report must not be longer than 8 pages. Calculations stated in tasks 1-3 must be included in appendices as Appendix A,B and C. Submit the semilog graphs for tasks 1 and 2 as a hard copy only. Suggested structure of report is: 

1. Introduction and objectives: Discuss the types of well tests and their specific applicability, associated instrumentation (gauges). Steps need in preparation of a well test.
    
2. Methodology:Stagesinwelltest,typeofdatacollected,typeofanalyses.
    
3. Results(summary):Discusskeyresultsfromfirstbuildup,productionanddrawdownfrombothmanual and software computations. Cross compare the results and comment on the observations.
    
4. Uncertainty analysis: Identify the sources of error in the estimation of reservoir properties and address the uncertainities in manual computations. Comment on how improvement of model in Kappa, may affect the estimates of reservoircharacteristics.
    
5. Conclusions