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Formation Resistivity Factor | Fundamentals of Fluid Flow ...

Fundamentals of Fluid Flow in Porous Media Chapter 2 Formation Resistivity Factor Porous media consist of mineral, rock fragments and void space. The solids with exception of certain clay minerals (such as shaly sands where clay shales produce electrical conductivity) are nonconductive. Generally the electrical property of a rock depends on void space geometry .

THE ROLE OF CLAYS AND SHALES IN LOW RESISTIVITY LOG .

The role of clays and shales in low resistivity log response Clay has been identified as a leading cause of low-resistivity pays. To a certain extent, shale, by way of its intimate association with clay, also shares responsibility for low resistivity readings across pay zones.

Generating Pseudo-Synthetic Seismogram with Resistivity ...

This work is a case study for the transformation of resistivity logs to pseudo sonic logs for the generation of pseudo synthetic seismogram considering the effect of gas. This research studies the relationship between resistivity and sonic logs in order to utilize the former for the generation of pseudo synthetics when sonic log is absent or poor.

Effectiveness of magnetotelluric method for geothermal ...

Effect of clay minerals on electrical resistivity 2 Montmorillonite reduces electrical resistivity more intensively than other clay minerals. Yokoyama et al. (1983) Resistivity decreases by more ... : temperature dependence 3. Uchida et al. (1994) 2D MT in Sumikawageothermal field 4. Uchida et al. (1994) SN-7D Well Logs, Sumikawa 5. Arnason et ...

Well Logging Questions and Answers – AONG website

♦ Resistivity logs are electric logs which are used to: – Determine HC versus water bearing zones. ♦ Because the rocks matrix or grains are non-conductive the ability of the rock to transit a current is almost entirely a function of water in the bores.

Chapter 20 - Petrophysics MSc Course Notes 20 Clay/Shale ...

Petrophysics MSc Course Notes Clay/Shale Effects on Porosity and Resistivity Logs Dr. Paul Glover Page 270 20. THE EFFECT OF CLAY ON POROSITY AND RESISTIVITY LOGS 20.1 Introduction The presence of clay minerals or shale in porous formations presents problems from the interpretation of wireline logs. For most logs these problems have been discussed in the relevant chapter.

Quantifying the Effect of Kerogen on Electrical ...

Interpretation of electrical resistivity logs in organic-rich source rocks has been challenging for petrophysicists. Conventional resistivity-porosity-saturation models (e.g., Archie's, Dual-Water, and Waxman-Smits equations) assume that saline water is the only conductive part of the formation.

Basic Relationships of Well Log Interpretation

porosity logs (i.e., sonic, density, and neutron logs) are covered next, then the resistivity logs. Nuclear mag-netic-resonance logs, although they provide porosity (among other quantities of interest), are presented after resistivity logs. This is due in part to their recent arrival and to their relative absence in historical data archives.

Petrophysical evaluation of well log data and rock physics ...

7/28/2017· The preprocessing stage normally employed is meant for the correction of environmental effects, indication of spatial minerals, correction of resistivity logs and so on (Rider 1996). For multi-well analysis, further preprocessing such as recalibration of logs is also required.

ARE PORE LINING CHLORITES A CAUSE OF LOW RESISTIVITY IN ...

effect of temperature on these properties was not studied. According to Worthington (2000), low resistivity in argillaceous sandstone reservoirs may be attributed either to the effect of microporosity, or to specific effects due to clays and/or to conducting minerals. Effect of CEC of usual clays, like smectite, illite and kaolinite, on

Petrography and petrophysical well log interpretation for ...

10/6/2013· their effect on the reservoir quality, and to compare reservoir properties of the different reservoir units. ... All the formations are water filled which is reflected by the low resistivity logs responses. The mature sandstones of the Stø Formation show high reservoir quality (high porosity and permeability) ... minerals and organic matter on ...

An Experimental Study of the Effect of Rock/Fluid ...

The possibility of a change in value resistivity due to CO2/brine/rock interactions, and the possible effect on CO2 monitoring and estimation are of immediate interest here. Preliminary results of an ongoing research work showed that a much longer experiment time accommodates CO2-brine-rock interaction which ultimately lead to change in rock ...

The Lowdown on Low-Resistivity Pay - Schlumberger

resistivity pay in sands, then explores the tools and techniques that have been devel-oped to evaluate such zones. A case study shows how log/core integration helps pin-point the causes of low-resistivity pay in the Gandhar field in India. Generally, deep-resistivity logs in low-resistivity .

Quick-look lithology from logs - AAPG Wiki

3/12/2019· Gamma ray logs. The common radioactive elements—potassium, thorium, and uranium—are normally insignificant in reservoir fluids, whereas they are important components of the rock system, especially of clay minerals. Gamma ray logs are therefore a good indicator of mineralogy.. Lithological responses

Log analysis: lithology - AAPG Wiki

3/6/2019· Additional minerals can be identified by incorporating the photoelectric, spectral gamma ray, and sonic logs. Some log measurements do not provide any relevant information in a given section. If the K, Th, and U values are uniformly low in the evaporite minerals, these logs have no resolving ability and are of little help in determining the ...

Petrophysical evaluation of low-resistivity sandstone ...

The combination of conventional logs, such as density, neutron and resistivity logs, is proven to be very effective in the evaluation of normal reservoirs. For low-resistivity reservoirs, however, an accurate determination of the petrophysical parameters with the conventional log reservoirs is very difficult.

Advances in resistivity processing improve well ...

Fixed depths of investigation are significant for propagation-resistivity logs because the investigation ... The effect is greatest on deeper ... He worked for Exxon Corp. in minerals exploration ...

UNDERSTANDING THE RESISTIVITIES OBSERVED IN GEOTHERMAL .

Because of this effect, estimates of water resistivity, based on measured bulk resistivity and porosity, are seldom greater than 10 Ωm, even ... proportion of clay minerals in the matrix, and K is a constant ... Representative examples of downhole resistivity logs, core resistivity, modelled subsurface resistivity (from MT surveys) ...

KGS--Geological Log Analysis--Log Overlay Lithology

shows an "hourglass effect" (the increase in density porosity is mirrored by a decrease in neutron porosity) We have already seen a gas effect in the Niobrara Chalk, when the logging operation was reviewed. Here is the gamma-ray and neutron-density porosity logs for #13-24 Helman P, now annotated with stratigraphy and the gas zone.

Effect of Conductive Solids on Formation Resistivity ...

Fundamentals of Fluid Flow in Porous Media . Chapter 2 Formation Resistivity Factor: Effect of Conductive Solids. The clay minerals present in natural rock act as a conductor and are sometimes referred to as "conductive solids", but it is actually the water in the clay and the ions in the water that are the conducting materials.

The effect of Clay on Porosity and Resistivity - Mechanics ...

The presence of clay minerals or shale in porous formations presents problems from the interpretation of wireline logs. For most logs these problems have been discussed in the relevant chapter. The problem is, however, especially bad in the interpretation of resistivity data, and also affects the porosity logs.

Glauconite Pellet Decrease Log Resistivity

Sensitive Clays Formation Damage Rock-log Calibration Low-resistivity Pay Resource Plays Tight Gas Fractures Wettability

An Experimental Study of the Effect of Rock/Fluid ...

An Experimental Study of the Effect of Rock/Fluid Interaction on Resistivity Logs during CO 2 Sequestration in Carbonate Rocks Abdulrauf Adebayo, Mohammed Mahmoud Petroleum Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia Email: [email protected] Received January 2014 Abstract

GEO4250 Reservoir Geology

• Resistivity is a basic measurement of a reservoir's fluid ... – Morphology and species of clay minerals. Tools • Conventional Electrical logs First developed before 1950 – Normal devices ... – Borehole effect – Adjacent bed effect – Invasion correction. Resistivity Logging Corrections - Borehole Effect ...

On Petrophysical Characterization of Low Resistivity ...

8/1/2014· Conductive minerals masking the presence of hydrocarbons in a reservoir on resistivity log. Causes of low resistivity: 1. Conductive minerals like pyrite, magnetite, and glauconite. 2. Clay ...

Dakota--Petrophysics 6--Resistivity Logs

The sensitivity of resistivity logs to water salinity can be used in an alternative method to SP log estimates of water quality. In a sandstone-shale sequence, resistivity variation is controlled by a variety of phenomena, including cation-exchange mechanisms by clay minerals within the shalier zones, conduction by metallic minerals, and the ...

(PDF) An Experimental Study of the Effect of Rock/Fluid ...

An Experimental Study of the Effect of Rock/Fluid Interaction on Resistivity Logs during CO2 Sequestration in Carbonate Rocks.pdf Journal of Geoscience and Environment P .

2013-07-31 A Petrophysical Model to Quantify Pyrite ...

1. Aldoleime, A M. "A New Technique for Deriving the Resistivity Parameters of Archie's Equation from Combination of Logs and Core Measurements." SPE Middle East Oil Show March 11-14, Bahrain (1989) 2. Clavier, C, A. Heim, and C. Scala. "Effect of Pyrite on Resistivity and Other Logging Measurements." SPWLA 17th Annual Logging Symposium (1976) 3.

OPEN HOLE WIRELINE LOGGING Self Learning Module

imply reservoir rock. Minerals like mica and feldspar are radioactive and give rise to relatively high GR readings, though their presence in a sand need not destroy reservoir properties. For reliable reservoir thickness determination, it is wise to cross check for indications of reservoir quality with other logs. Logging operations

Different shale distributions in low resistivity log ...

By far the most important use of resistivity logs is the determination of hydrocarbon-bearing versus water-bearing zones.Because the rock's matrix or grains are non-conductive and any hydrocarbons in the pores are also non-conductive, the ability of the rock to transmit a current is almost entirely a function of water in the pores.