气藏工程气藏工程气藏工程 (30).pdf

5.9 Type Curve Analysis5.9 Type Curve Analysis-1 1GasGas-well test analysis using type curveswell test analysis using type curvesType curves:plots of theoretical solutions to flow equations,presented in dimensionless variables.Identify the appropriate reservoir modelIdentify the appropriate flow regimes for analysisEstimate reservoir properties Development of type curves Gas-well test analysis using type curves Gas-well test analysis with derivative type curvesMain content:1、Development of Type CurvesAs a matter of convenience,type curves usually are presented in terms of dimensionless,rather than real variables.ktrcEikhBqptpti442BqppkhpiD22wtDrckttwDrrr DDDtrEip4212At the wellbore,1Dr1124DWDDppEit Line source solution for slightly compressible liquids2w2/r()1141.220.00026374t wrkh pipEiqBktC r Remay and Gringarten type curves22111,00,01DDDDDDDDDDDDeDwDDDDDDrDwDDDDrppprrrtprpR tdppCrdtrpppS rrRadical diffusivity equation Initial condition is uniform pressureOuter boundary condition is an infinite acting or unbounded reservoirInner boundary condition is constant rate flow with wellbore storage and skin factorRamey Type Curvesis dimensionless wellbore-storage coefficientDCGringarten Type CurvesRameyGringarten2、procedure of using Type CurvesThe theory underlying type-curve matching is that the type curve andtest data plots differ only by displacement of both coordinates byconstants.220.0002951lglg 0.0002951lg()lgtwDDt wc hrtktkhtCc rCClglglg141.2Dikhpppq BThe horizontal axes of the type curve and test data plots are displacedby the constantThe vertical axes are displaced by the constantmpDpphBqk2.141DsDCeCs2ln5.00.0002951lglg()lgDDtkhtCClglglg141.2Dikhpppq B/1DDDtC p24qBtortCp20.8936DtwCCC hr20.0002637/DDDgt wMPktor tCtCC r(1)Plotfor a drawdowntest orfor a builduptest.Make the plot on either tracingpaper or loglog paper the same size asthe gringarten et al.type curve.,()vsa ia wfppt,ws,()vsaa wfaeppt(2)If a unite slope line is present,calculate CD20.0372ggaeDagt wq Btor tCpC r24gaeaqBtortCpSteps:(3)Record the values of the parametercorresponding to the matched typecurve2sDC e(4)Record the values of,aDpp,/DDt tC(5)Calculate permeability141.2gggDaMPq Bpkhp(6)Calculate CD20.0002637/DDDgt wMPktor tCtCC r(7)Calculate s20.5lnsDDC esCOne inherent problem in type curve analysis is the difficulty in finding a unique match of the data.The data can be matched on more than one curve,so more than one solution is possible.Type curve should not be the primary analysis technique but should be used to complement to semilog analysis.GasGas-well test analysis using type curveswell test analysis using type curves(End)(End)