Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability

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Dept. of the Interior , Washington
Geophysical well logging, Groundwater flow - Measur
The Physical Object
Pagination24 p.
ID Numbers
Open LibraryOL22058609M

Geophysical logs can be used to estimate porosity, formation-water resistivity, and intrinsic permeability for geohydrologic investigations, especially in areas where meas­ urements of these geohydrologic properties are not by: Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability Water Supply Paper By: Donald G.

Jorgensen. The relation of formation factor to resistivity of formation water and intergranular permeability has often been investigated, and the general consensus is that this relation is closest when established in a clean-sand aquifer in which water quality does not vary substantially.

When these restrictions are applied, the following standard equation is a useful tool in estimating the resistance of. USE OF GEOPHYSICAL LOGS TO ESTIMATE THE QUALITY OF GROUND WATER AND THE PERMEABILITY OF AQUIFERS By ABSTRACT The relation of formation factor to resistivity of formation water and intergranular permeability has often been investigated, and the general consensus is that this relation is closestFile Size: 1MB.

Characterization of the spatial distribution of hydrogeologic parameters in an aquifer is important to understanding the hydrodynamics of a groundwater flow system. The operational procedure presented in this paper uses core permeability and porosity data and geophysical logs to characterize hydrogeologic parameters, especially hydraulic conductivity (K).Cited by: 4.

Using Geophysical Well Logs to Estimate the Porosity System of Albian Carbonates of Campos Basin - Rio de Janeiro Conference Paper (PDF Available) May with 40 Reads How we measure 'reads'. Log analysts use the tools' characteristic responses to help determine fluid type and lithology.

For example, in a sandstone formation, with porosity computed using correct parameters (left), the curves overlie one another at the correct porosity of 30% in water, cross over somewhat in oil, cross over a great deal in gas and separate in shales.

Details Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability FB2

in a water-producing well, using a catalog of water resis-tivity values calculated from the SP log using the Schlum-berger chart book (Schlumberger ). R w from a resistiv - ity–porosity log is found by the calculation of the wa R log as follows: where R t is from the deep investigation resistivity log, and F is from the porosity log by: 2.

Lithology Value (gr/cm3) Fluid Value (gr/cm3) Sandstone Fresh Water Limestone Salt Water Dolomite Methane Anhydrite Oil Salt Calculate the Water Saturation There are so many methods to calculate water saturation, the user may use Archie’s,[2] Simandoux’s (), etc.

which will use different. GAMMA LOG Records the natural-gamma radiation emitted from rocks penetrated by the borehole. The gamma log often is used to define lithology and correlate geologic units between boreholes. Caliper and natural-gamma logs of well BK, Bridgetown Township, northern Bucks County.

6 7. 0 50 0 20 40 60 80 0 Get this from a library. Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability. [Donald G Jorgensen]. Estimation of Permeability From Well Logs Using Resistivity and Saturation Data Article (PDF Available) in SPE Formation Evaluation 12(1) March with.

Description Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability EPUB

Use of geophysical logs to estimate the quality of ground water and the permeability of aquifers Paperback – January 1, by J.

Hudson (Author) See all formats and editions Hide other formats and editions. Price New from Used from Paperback Author: J.

Hudson. For a given R w, if water saturation and rock resistivity are known, then F can be calculated. Because F is a function of porosity and tortuosity, permeability, k, should be a function of F.

Eventually, if permeability can be represented as a function of F, it also can be represented as a function of F a and S w n according to Eq. 5, namely.

Add tags for "Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability". Be the first. Geophysical logs are logs created by raising or lowering a set of probes and/or sondes in a well.

The probes take measurement of the formation resistivity. high porosity is a good conductor and will have a low resistivity.

Saline pore water also causes low resistivity. Clays are good electricalFile Size: KB. To find hydrocarbon indications and obvious water zones, compare deep resistivity to porosity, by mentally or physically overlaying the density porosity on top of the resistivity log.

High porosity (deflections on the density log to the left) and high resistivity (deflections to the right) usually indicate oil or gas, or fresh water. Many older wells do not have porosity indicatimg logs, but may have a microlog.

Porosity can be derived, but it should be calibrated against core or more modern logs in offset wells. The response equation is based on Archie's formation factor and water saturation equations.

Calculate porosity from the microlog if there is positive separation. Using a log reading deep resistivity, R t can be measured in the suspected oil zone and R o in one that can be reasonably assumed to be % water saturated. Thus, S w may be calculated throughout a suspected reservoir.

This is the simplest method and is only valid for clean (i.e., clay-free) reservoirs. If a clay matrix is present, the resistivity of the reservoir is reduced, and oil. The user will be able to interpret the lithology by using several logs, there are gamma ray, spontaneous potential, resistivity, and density lly, a formation with high gamma ray reading indicates that it is a shaly or shale, when the low gamma ray reading indicates a clean formation (sand, carbonate, evaporite, etc.), lithology interpretation is very important in reservoir Competition: December The porosity ANN is a simple three‐layer network using sonic, density and resistivity logs for input.

The permeability ANN is slightly more complex with four inputs (density, gamma ray, neutron porosity and sonic) and more neurons in the hidden layer to account Cited by: Most commonly, to estimate permeability, we can use values of porosity, pore size distribution, and water saturation from logging data and established correlations.

One benefit of using wireline log data to estimate permeability is that it can provide a continuous permeability profile throughout a Cited by: Figure 2. Part of the first geophysical log obtained by the Schlumberger brothers in resistivity Since this first log was run, geophysical well logging has developed into a billion-dollar global industry serving a wide range of industry and research activities.

Geophysical well logging is a key technology in the petroleum industry. velocity to porosity and the self-similar model to get from porosity to resistivity, both as Carcione et al.

() present. Following En-gelmark (), we use the dual-water model from Clavier et al. () to get depth-dependent brine resistivity. Other parameters are either constant or a linear function of depth.

Finally, we use. Interpreting geophysical well logs 1.

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Q.3 Calculate formation water resistivity at oF if the concentration of N, ,00 1ndusing graph and equations. Q.4 If the formation resistivity in the above cases (Q.3) is Ω-m at oF and the cementation factor is 2.

HW Q.5 Calculate porosity and water saturation if the. The resistivity logs in figure 3 were used to calculate the quality of the water in aquifers at the Kipling well site in Saskatchewan, Canada.

The left trace of the two normal resistivity logs shown is the cm (in) normal, which was used to calculate Rw for three of the shallower aquifers intersected. gy, permeability, and water saturation. Additionally, the resistivity of the rock is important because it is directly measured and is an essential part in the inter-pretation process.

It is essential that the reader under-stand these properties and the concepts they represent before proceeding with a study of log interpretation.

Porosity. Porosity combinations • When using a single porosity measurement, lithology must be specified, through the choice of a matrix value, for the correct porosity to be calculated • When using two or more measurements, lithology may be predicted (along with porosity), but with some ambiguity • Measurement preferences (in order of choice).

One approach to obtaining sediment porosities from downhole logs is to use the electrical resistivity logs and Archie's relationship between the resistivity of the formation (R t) and porosity (): R t /R w = a-m, where a and m are constants to be determined and R w is the resistivity.

plugs have the following porosity and permeability: 7% and mD for A33, 15% and mD for F, 17% and Table 1. Porosity is the helium porosity, permeability is in mD, Sw is the water saturation reached for resistivity measurements,File Size: KB.

An Approach for Estimating Porosity from Sonic-Logs in Shaly Formations Walid M. Mabrouk Geophysics Dept., Faculty of Science, Cairo University, Giza, Egypt Received: 8/10/ Accepted: 30/5/ Abstract.

The determination of bulk volume water (BVW) and hydrocarbon (BVHC) involve the determination of effective porosity (φ).Using Geophysical Logs to Estimate Porosity, ^Vater Resistivity, and Using geophysical logs to estimate porosity, water resistivity, and intrinsic permeability. (U.S.

Geological Survey Water-Supply Paper; ). Bibliography: p. The porosity was estimated by using Archie’s law (Eq. 1), which relates the bulk resistivity of granular medium to the porosity of saturated porous Cited by: 5.