(11)--11-Type Curve Analysis气藏工程气藏工程.ppt

5.9 Type Curve Analysis-25.9 Type Curve Analysis-2Gas-well test analysis with derivative type curvesGas-well test analysis with derivative type curves？The data can be matched on more than one curve,so more than one solution is possible.Bourdet et al.Derivative Type curveAs a supplement to pressure/time plots,the pressure derivative is used widely,specifically to identify reservoir types.tD/CD0.01100100,000PDWBSTransitionRadial FlowEarly Time RegionMiddle Time RegionUnit Slope LineHorizontal DerivativeLine source solution(1)From the test data,calculate the following derivatives.For a drawdown testFor a buildup test(2)Plot (or )and as functions of t(or )(3)With the test data plot fitted to the type curve,record values of(pa,pD)and(t,tD/CD)for a drawdown test or(tae,tD/CD)for a buildup test at the match point.StepstD/CD0.01100100,000PDteq11,0001,000 PtD/CD0.01100100,000PDteq11,0001,000 PAlign data with horizontal part of type curvestD/CD0.01100100,000PDteq11,0001,000 PStop when data align with horizontal stemsBegin to move toward unit slope line1.Plot(pa,i-pa,wf)vs.t for a drawdown test or pa,ws-pa,wf vs.tae=ta/(1+ta/tp)for a buildup test,and pressure derivatives.2.Find the type curve that most nearly fits all plotted test data.Record the value of the parameter corresponding to the matched type curve.3.Record values of (pa,pD)and(t,tD/CD)for a drawdown test or(tae,tD/CD)for a buildup test at the match point.Type-Curve Analysis Procedure:4.Calculate permeability from the pressure match point.5.Calculate CD from the time match point.6.Calculate s using and CD from step 5.Identify reservoir typeC,s constantC changeSingle porositydual porositytriple porosityConstant pressureImpermeable boundaryinfinite boundaryGas-well test analysis with derivative type curvesGas-well test analysis with derivative type curves(End)(End)