Leverett j function 6 mercury injection capillary pressure samples were taken into account considering unimodal behavior in their trend rock types classified with capillary pressures were associated with. The results of simulations using this permeability method show a much improved quantitative match to. Porosity corederived leverett, 1941 leverettj function. Application of flow zone indicator and leverett jfunction. The p c s w data are usually compared first on a leverett j function basis. J dimensionless pc function, function of sw c conversion constant 0. However, theories of capillary pressure indicate that leverett j. The buckley leverett theory 1942 estimates the rate at which an injected water bank moves through a porous medium.
The leverett j function was then correlated with the normalized water saturation for each reservoir unit to group the capillary pressure data of that unit into one curve. Theempirical formula ofthe relative permeability calculationiseasier touseand moreconvenient withthe jfunction prediction formulathanwiththeearlier formula. Theleverettj function isderived basedonthecapillary bundlemodel. Theleverettjfunction isderived basedonthecapillary bundlemodel. Saturation height methods and their impact on volumetric.
Carbonate reservoir is known as heterogeneous reservoir due to its pore complexity caused by depositional setting and diagenetic process. Leverett j function in petroleum engineering disambiguation page providing links to topics that could be referred to by the same search term this disambiguation page lists articles associated with the title j function. Buckley leverett analysis norwegian university of science and technology professor jon kleppe department of geoscience and petroleum 49 w dx dt dt t. Research shows that rocks should be described using the directmapping pore network model 812 however, owing to the research background and technical level of the leverett era, rocks were described using the bundleoftubes model or the capillary bundle model.
The leverett municipal light plant lmlp manages leverettnet as a telecommunications network, pursuant to massachusetts general laws, chapter 164, section 47e the lmlp contracts with third parties to provide network operator and internet service provider functions over the network. Theempirical formula ofthe relative permeability calculationiseasier touseand moreconvenient withthe j function prediction formulathanwiththeearlier formula. Leverett introduced the model in 1941 and showed that dimensionless capillary j s wfunction varies only with fluid saturation. Leverett postulated that the j function of similar lithology has universal significance, and in most cases, all capillary pressures of a reservoir. The prediction of reservoir initial fluid saturations. Sep 07, 2016 therefore, the fitting trend for the average capillary pressure jfunction is a power function rather than an exponential or a polynomial one because the jfunction of the same strata and lithology provides a better comparison 23,16,24, 10 representative rocks from the wj well, shan 22 strata of the zy oil field in china were selected for the practical calculation. The leverett jfunction is a way of expressing the capillary pressure in dimensionless form, which takes account for different average pore size and interfacial tensions. Q for news about security, streaming, and other topics, see the blog basic information leverettnet is a. This complexity can create comprehension about its storage capacity and flow capacity, including water. Capillary pressure data are obtained on small core samples that represent an extremely small part of the reservoir and, therefore, it is necessary to combine all capillary data to classify a particular reservoir. The classic method is based on leverett s j function approach 5. The classic method is based on leveretts jfunction approach 5. Application of flow zone indicator and leverett jfunction to. The jfunction, which synthesizes the fluid ift, wettability, permeability, and porosity, is used to represent the characteristics of the reservoir capillary pressure curve.
The high displacement pressure of the porous plate allows brine from the plug to pass through, but prevents flow of the displacing fluid normally air. Leverett jfunction the leverett jfunction is a way of expressing the capillary pressure in dimensionless form, which takes account for di. Other commonly used methods in the ukcs include johnson 6, cuddy et al. Spe 159991 rock classification in carbonate reservoirs based. This is a very useful scaling for dealing with laboratory measurements that may be performed with. Consequently, to convert data from one fluid system to the other, interfacial tensions. Permeability, porosity, and elevation are known for each sample. The capillary bundle model was widely applied as the classical model 15 such as in.
This disambiguation page lists articles associated with the title jfunction. View notes 2015 leverett jfunction lecture from pte 461 at university of southern california. But, leveretts jfunction has proven valuable for correlating capillary pressure data within a. Modelling subcore scale permeability in sandstone for use in. The limitation of leverett j function is investigated and it has been shown that leverett j function is suitable for capillary pressuresaturation pcs w function scaling from one formation. Pr b a x ab x x apr 22, 2008 the problem of capillary pressure upscaling and generation of initial water saturation data on the simulation scale consistent with the underlying geological model is addressed analytically. The j function, which synthesizes the fluid ift, wettability, permeability, and porosity, is used to represent the characteristics of the reservoir capillary pressure curve. Theprediction jfunctionmodelisapower functionthat pointsthe wayforitsapplication.
A new method for normalization of capillary pressure curves. As a method to compare capillary pressure data for a range of practical applications, leverett proposed the semiempirical jfunction 1 where js w is the jfunction, s w is the wettingphase saturation, p c sw is the capillary pressure. View notes 2015 leverett j function lecture from pte 461 at university of southern california. Crains petrophysical handbook capillary pressure pc. A prediction model of the capillary pressure jfunction. But, leveretts jfunction has proven valuable for correlating capillary pressure data within a lithologic rock type. The fact that the capillary pressuresaturation curves of nearly all naturally porous. Pdf modeling of capillary jfunction for heterogeneous. The function is important in that it is constant for a given saturation within a reservoir, thus relating reservoir properties for neighboring beds.
The approach uses fractional flow theory and is based on the following assumptions. The probability that an observation taken at random from a population with a density function px lies between xa and xb is as follows. This is a very useful scaling for dealing with laboratory measurements that may be performed with fluid pairs and at conditions in terms of average porosity and. The j function is obtained from experimental data by plotting against s w. Capillary pressure properties of mesaverde group low. This function is traditionally called the leverett j function. Determining water saturation from capillary pressure in. The approach is based on the concept of random spatial variations of permeability and porosity.
We will use the upper case j in keeping with the spe nomenclature of using the upper case for pc. Laboratory measurement of capillary pressure norges tekniske hgskol. Pr b a x ab x x leverett j function, a modified j function is defined which includes pore size distribution effect in the form of saturation exponent, irreducible liquid saturation. The combination is often considered an estimate of the mean hydraulic radius of pore throats. Buckleyleverett analysis norwegian university of science and technology professor jon kleppe department of geoscience and petroleum 49 w dx dt dt t. Capillary pressure curve an overview sciencedirect topics.
If an internal link led you here, you may wish to change the link to point directly to the. Interfacial surface tension k permeability corederived. The results of simulations using this permeability method show a much improved quantitative match to experimental saturation measurements over the porosityonly based permeability models. Furthermore, these methods are based on core measurements, hence are not applicable to uncored reservoir zones. Modelling subcore scale permeability in sandstone for use. Leverett postulated that the jfunction of similar lithology has universal significance, and in most cases, all capillary pressures of a reservoir. The capillary pressure is applied across the test plug and a brine saturated porous plate. Laboratory measurement of capillary pressure norges tekniske hgskol nth. Development of a modified capillary pressure jfunction. Leveretts jfunction is a technique for correlating capillary pressure to water saturation and rock properties. Leverett and coworkers, based on the evaluation of gaswater capillary pressure data for drainage and imbibition in unconsolidated sands, proposed the following definition.
The buckleyleverett theory 1942 estimates the rate at which an injected water bank moves through a porous medium. Buckleyleverett theory for immiscible displacement. The leverett j function is an attempt at extrapolating capillary pressure data for a given rock to rocks that are similar but with differing permeability, porosity and wetting properties. I arifianto, s s surjono, g erlangga, b abrar, e yogapurana, application of flow zone indicator and leverett jfunction to characterise carbonate reservoir and calculate precise water saturation in the kujung formation, north east java basin, journal of geophysics and engineering, volume 15, issue 4, august 2018, pages 17531766. Leverettnet fiberoptictothe home for leverett, massachusetts. It assumes that the porous rock can be modelled as a bundle of nonconnecting capillary tubes, where the factor \\sqrtk\phi\ is a characteristic length. Leverett jfunction the imperial college lectures in. The fact that the capillary pressuresaturation curves of nearly all naturally porous materials have many.
It is an effective method for analyzing data on capillary pressure. Capillary pressure an overview sciencedirect topics. Theprediction j functionmodelisapower functionthat pointsthe wayforitsapplication. Tarek ahmed, in reservoir engineering handbook fifth edition, 2019. Figure 6 illustrates a correlation of sand pack capillary pressures by leverett using this function. We have revised the previously published expression for the coarse scale capillary pressure desbarats, water.
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