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Click To Edit Master Title Style,Click to edit master text styles,Second level,Third level,Fourth level,Fifth level,*,Laboratory Measurement ofCapillary Pressure,1,LABORATORY METHODS FOR MEASURING CAPILLARY PRESSURE,Porous diaphragm method,Mercury injection method,Centrifuge method,Dynamic method,Determination of P,c,(S,w,) function,2,POROUS DIAPHRAGM METHOD FOR CAPILLARY PRESSURE,Scale of,Brine,Ultra-fine,fritted,glass disk,Seal of,red oil,squared,paper,Saran tube,Crude oil,Nitrogen,pressure,Neoprene,stopper,Nickel-,plated,spring,Kleenex,paper,Core,Porous diaphragm method of,measuring capillary pressure,Modified from Welge and Bruce, 1947,3,CAPILLARY PRESSURE USING POROUS DIAPHRAGM METHOD,Capillary pressure, psia,Wetting phase saturation, %,Measured,data points,Irreducible,Wetting Phase,Saturation,Displacement,pressure,0,100,4,COMMENTS ON POROUSDIAPHRAGM METHOD,Advantages,Very accurate,Can use reservoir fluids,Disadvantages,Very slow (days, weeks, months),Range of capillary pressure is limited by “displacement pressure” of porous disk,Wetting phase of disk should be same as core sample,Holes in porous disk act as capillaries, allowing only wetting to flow out until displacement pressure is exceeded,5,MERCURY INJECTION METHOD FOR CAPILLARY PRESSURE,Lucite window,Lucite window,To,0-2,000 psi pressure,gauge,Regulating valve,atmosphere,U-tube monometer,Cylinder,0-200 psi pressure gauge,From Purcell, 1949,6,COMMENTS ON MERCURYINJECTION METHOD,Advantages,Results obtained quickly (minutes,hours),Method is reasonably accurate,Very high range of capillary pressures,Disadvantages,Ruins core / mercury disposal,Hazardous testing material (mercury),Conversion required between mercury/air capillary data to reservoir fluid systems,7,CENTRIFUGE METHOD FOR DETERMINING CAPILLARY PRESSURE,Seal Cap,Core holder body,Window,Tube body,Support disk,O - Ring,From Slobod and others,1951,8,COMMENTS ON CENTRIFUGE METHOD,Advantages,Results can be obtained fairly quickly (hours, days, weeks),Reasonably accurate,Can use reservoir fluids,Disadvantages,Complex analysis required can lead to calculation errors,9,DYNAMIC METHOD OF MEASURING CAPILLARY PRESSURE,To,atmosphere,Oil burette,Porcelain,plate,Oil inlet,P,o,P,g,P,c,Gas,inlet,Gas,outlet,Core,From Brown, 1951,10,COMMENTS ON DYNAMIC METHOD,Advantages,Simulates reservoir flow conditions,Can use reservoir fluids,Disadvantages,Very tedious to perform (weeks, months),High cost,11,AVERAGING CAPILLARY PRESSURE DATA USING THE LEVERETT J-FUNCTION,The Leverett J-function was originally an attempt to convert all capillary pressure data to a universal curve,A universal capillary pressure curve does not exist because the rock properties affecting capillary pressures in reservoir have extreme variation with lithology (rock type),BUT, Leveretts J-function has proven valuable for correlating capillary pressure data,within,a lithology (see ABW Fig 3-23).,12,EXAMPLE J-FUNCTION FOR WEST TEXAS CARBONATE,13,DEFINITION OF LEVERETT J-FUNCTION,(,),f,q,s,k,C P,c,S,J,w,cos,=,J-Function is,DIMENSIONLESS, for a particular rock type:,Same value of J at same wetting phase saturation for any unit system, any two fluids, any exact value of k,f,(k/,f,),1/2,is proportional to size of typical pore throat radius (remember k can have units of length,2,),C is unit conversion factor (to make J(,S,w,) dimensionless),14,Flow,Units,Gamma Ray,Log,Petrophysical,Data,Pore,Types,Lithofacies,Core,1,2,3,4,5,Core,Plugs,Capillary,Pressure,f,vs k,P,c,(S,w,) Depends on k,f,High Quality,Low Quality,Function moves up and right, and becomes less “L” shaped as reservoir quality decreases,15,LEVERETT J-FUNCTION FOR CONVERSION OF P,c,DATA,16,J-function,is,useful for averaging capillary pressure data from a given rock type from a given reservoir,J-function can,sometimes,be extended to different reservoirs having same lithologies,Use extreme caution in assuming this can be done,J-function usually,not,accurate correlation for different lithologies,If J-functions are not successful in reducing the scatter in a given set of data, then this suggests that we are dealing variation in rock type,USE OF LEVERETT J-FUNCTION,17,
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