The minimum log data required by the spreadsheetbased software are a porosity. This is caused by the additional electrical conductivity of the clay. Archie phit for organic shales, archie or simandoux for conventional systems with rw remapping in all cases. Typical parameters for the archie equation for consolidated sandstones are a0. This is a 5 day course that covers wireline logging, mwdlwd and their specific applications for wellbore stability and includes 12 hours daily of workshop examples. The rest of the story gene ballay and nelson suarez. Water saturation sw archie 1942 archie s equation is one of the most known ways to calculate water saturation. The video below is a quick tutorial on how to perform a water saturation calculation using danomics petrophysics software. Danomics petrophysics software water saturation in 10.
Petrophysics petro is latin for rock and physics is the study of nature is the study of the physical and. From this discipline of petrophysics, archie s equation is. The most popular versions among interactive petrophysics users are 4. Archie, dual water, juhasz, waxmansmits, simandoux, and indonesia are available.
The following equations are used for sw calculation. Considering rt is the true resistivity of the reservoir. Essay about archie equation petrophysics 6528 words. More than 30 different water saturation models have been proposed over that period, of which three or four are more popular than the others. Petrophysics and software development, and 3d analytical. This course will be suitable for all drilling engineers, directional drillers and other geoscientists associated with drilling. Holmes established his own consulting practice, involving petrophysics, technical due diligence, consulting to the united nations worldwide, expert witness activities, and instructor to ihrdc and the university of brunei. The application contains a set of useful functions for geologists, geophysicists, engineers and any other person interested in borehole geophysics, petrophysics or well log interpretation. Wyllie, raymerhuntgardner, raigaclemenceau, field, and velocity equation are available. This provides linear and nonlinear response functions for the wireline and lwd neutron tools of the major service companies. The archie equation assumes that the matrix is nonconducting. We start with archie s water saturation equation and take the logarithm to obtain linear relationships between reservoir porosity and bulk resistivity.
The cementation factor of archie s equation for shaly sandstone reservoirs article pdf available in journal of petroleum science and engineering 232. If you have specialised petrophysical software, then by all means use it. This uses the same parameters used in other equations from other authors e. He logically traced the interconnections between rock type, porosity, permeability, fluid saturations, water salinity, hydrogen content, capillary pressure, natural radioactivity, response to neutron bombardment, spontaneous potential, and. Water saturation from electric logs outline what is water saturation and why do we care. Tables 5 and 6 contain the solution of three regression equations, which give archie s parameters for the sandstone and carbonate samples. You drive the order of actions and the amount of guidance provided. How to calculate rw and m porosity cementation exponent. Using archies law to find formation water resistivity. Work on thousands of wells with data located anywhere in the world, as an individual or as part of a team. Hence use of the archie equation in shaly sands will result in too low a hydrocarbon saturation. Archie equation archie equation is the most famous equation used by petrophysicists to determine the water saturation in the reservoir in hand. Around 1950 gus archie, working at shell oil, changed petroleum exploration by developing a theoretical foundation for elog interpretation based on certain electrical properties of rocks.
The extensions of the archie resistivity equations for formation factor and water saturation to the case of shaly sands has been undertaken by many investigators over the last 45 years. The quality of the water saturation values derived from the archie. The most commonly used water saturation equation is that created by gus archie in 1944. The archie equation may not apply at low sw values. The equations, which are known as the archie equations, relate the resistivity of a formation to the resistivity of the fluids saturating a formation, the porosity of the formation and the. S w can also be estimated using a graphical representation of the archie equation known as the pickett plot see also. Using archie s law to find formation water resistivity seems like a simplistic approach to hydrogeology. This software is an intellectual property of senergy group limited. In 1998, michael combined consulting activities with software development, to form digital formation, inc. The equation is then run through 5 times on each side. The m cementation exponent is the adimensional power parameter for porosity in the archie water saturation equation, the simandoux equation, the indonesia equation, and others. Swa water saturation from archie method fractional comments. This equation is not shale corrected, so it should not be. Pdf the accurate calculations of petrophysical properties in carbonate.
Crains petrophysical handbook resistivity concepts. This rmf must be a continuous curve generated by extrapolating the. The archie equation for clean formation can be expressed as follows. Crains petrophysical handbook water saturation archie. Used by petrophysicists and log analysts in manual interpretation to have a quick look evaluation. Here, denotes the porosity, the electrical conductivity of the fluid saturated rock, represents the electrical conductivity of the brine, is the brine saturation, is the cementation exponent of the rock usually in the range 1. While useful for a quick look this is a method which requires that we make a number of assumptions about the relationship between porosity and water resistivity.
Work the way you want with powerlog petrophysical software. Determination of rw using different methods sp, rwa, pickett plot etc. Danomics petrophysics and log analysis software uses robust petrophysical workflows so that users can get consistent and highquality results. The equations on the following pages convert the measurements commonly made in open uncased boreholes into the formation properties of scientific and economic interest to us. The two recommended equations are the archie equation for clean reservoirs and the. Water saturation is one of the final steps in the petrophysical workflow and will directly play into your calculations of inplace volumes. An ebook reader can be a software application for use on a computer such as microsofts. Petrophysicists use cutoffs for calculation of average values that are. This author included in his equation different physical rock properties and measurements from different well logs like tortuosity, water and formation resistivities, saturation exponent, and porosity.
In the original paper, the samples had water saturation greater than 15%. The archie equation was the first empirical model built 1942 to estimate the water saturation in non conductive matrix rocks. Resistivity logging rt ro, waterleg rt ro, hydrocarbons archie s equations and using then to calculate water saturation when doesnt archie work. He played the key role in identification of producible horizons at the giant elk city field in oklahoma, an episode which dramatically demonstrated for. This technique is a mathematical manipulation of archie s formula and considers the equation in the form of three regression equations to get the three unknowns a, m and n. Archie is perhaps best known for his contributions to petrophysics. This equation is best used in clean nonshaley reservoirs. These equations are highly nonlinear and may give unreliable results.
The prototype equation relating rock porosity to various electrical properties of rock bears his name. Sxo is calculated in the same way, with rxo replacing rt, and rmf replacing rw. Applied formation evaluation and basic log analysis using. Petrophysics msc course notes resistivity theory dr. Archie equation petrophysics 6518 words 27 pages introduction archie unleashed is an attempt to put the basic log analysis methodology for computing water saturation into a readable reference document. Sw water saturation of the uninvaded zone n saturation exponent, which varies from 1. In addition to the toc, lom and dominant flow regimes continuous vs. Water saturation s w can be measured directly from a sealed core, which is an expensive method, or it can be calculated from the archie equation, which is less expensive. A graphical solution to archie s equation so that plotting resistivity against porosity both on logarithmic scales will produce linear arrangements of the data. Water saturation calculation using archie s equation and summaries. Archie between the formation factor f and porosity phi, in which f 1 phi m, where the porosity exponent, m, is a constant for a particular formation or type of rock. Common openhole petrophysics interpretation equations. Archies equation, which assumes clean waterbearing formation. The socalled archie equation is most readily expressed in the form below.
Sw on the right is calculated initially from the archie equation using m and n in place of m and n. Archie developed his famous equation to calculate, from well log parameters, the water saturation s w of the uninvaded zone in a formation next to a borehole. Water saturation sw simandoux 1963 another well known equation to calculate water saturation is simandouxs equation 1963. The higher the m, the higher sw water saturation this parameter m depends upon the pore space structure connectivity, the matrix consolidation, and the grains shape more than the size. The m exponent in carbonate petrophysics r e gene ballay, phd. In petrophysics, archie s law relates the insitu electrical conductivity of a sedimentary rock to its porosity and brine saturation. Archie s equation was improved throughout time by several researchers as winsauer 1952, carothers 1968, porter and carothers 1970, timur 1972, tixier etc. It usually works well with clean clastic sandstones and carbonate rocks.
To enroll in the full course visit log response course automatic transcription one of the methods thats now widely used is the archie s water saturation equation and all the derivative equations that have a shale corrections built in them based on archie s work. Water saturation calculated from openhole resistivity measurements is a primary input to hydrocarbon reserves evaluation. The choices of tools for the evaluation program are usually made by the. Pdf calculation of petrophysical properties for mishrif carbonate. For the first time, archie set out clearly the waft and weave of the complex fabric that is petrophysics.
In the original work, archie proposed that m lay between 1. In 1952 archie stated in discussing the petrophysics of limestones, it is necessary to first classify them in a manner to portray as much as possible the essential pore characteristics of a reservoir. Water saturation archie model crains petrophysical handbook. Top 10 landmark papers in petrophysics and formation. All shale corrected saturation models revert to this equation when vsh 0, so shale.
The saturationheight modeling module provides coretolog integration via the following workflow. Larionov, clavier, steiber, neutron, resistivity and from double shale indicators. Another possible way is to create a pseudo rxo curve by calculating it using archie s equation, assuming that the invaded zone is 100% flushed with mud filtrate with a resistivity of rmf. Rw zone not considered in the petrophysical interpretation, unreliable values for rw. Log equation expression write your own can save this and share with others.
Application of archie equation in carbonate reservoir. Archie s equation is the water saturation model for the determination of water saturation. Pdf the cementation factor of archies equation for. Shale volume from single indicators like sp, gr corrections. Interactive petrophysics free version download for pc. Reservoir evaluation is one of the critical tasks of any reservoir exploration and field development plan. Fluid levels within the reservoir formation water what is it composed of. The petrophysics of shales and organic rich shale associated with carbonates. This pc program was developed to work on windows xp, windows 7, windows 8 or windows 10 and is compatible with 32bit systems. In an earlier note the m exponent in carbonate petrophysics we discussed the physical meaning and range of values of archie s m exponent. Ppt deterministic petrophysics powerpoint presentation. This equation is not shale corrected, so it should not be used in shaly zones. Uncertainty analysis of archies parameters determination.
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