A commonly used shaly sand equation to calculate water saturation is the Fertl (1975) method. Other equations and techniques are described by Asquith (1990). The Fertl method has an easy calculation and does not need a value for the resistivity of the adjacent shale.

In a petrophysical sense shaly sands are clastic rocks with ‘excess conductivity’, that is a conductivity greater than the free water conductivity treated by the Archie’s equation. The Archie equation treats all rock conductivity as being due its free water so when Cw=0 then whole rock conductivity Ct=0.

A wide variety of procedures are currently in routine use for the evaluation of shaly sands. Each of these can furnish a significantly different reservoir evaluation. Yet, no one method predominates within the industry.

The conductance and electrochemical behavior of shaly sands and their relation to log interpretation have been studied by many workers. Wyllie and Lynch reviewed this work in some detail. Virtually all laboratory measurements of electrical resistivity and electrochemical potential of shaly sands published to date are the work of Hill and Milburn.

2022年4月1日 · The study based on the calculation of V sh of three intervals (shaly sand, sandstone and shale intervals) of the Alif Member, Halewah oilfield, Sab'atayn Basin (Fig. 1), mainly aims to calculate the V sh and effective porosity by neutron-density porosity crossplot and conventional petrophysical log analysis.

The basic formulas which make up shaly sand analysis are presented and discussed in this chapter. We begin by introducing methods for determining the volume of clay (V d) in a reservoir. Once the amount of clay has been estimated, we use the volume of clay (V cl) value to correct data from porosity logs and to calculate effective porosity (ϕ e).

2019年12月13日 · In this paper, the layer-wise interpretation of petrophysical properties was undertaken by using wireline logs to obtain parameters to build a reservoir simulation model. The properties extracted include shale volume, total and effective porosities, sand fractions and sand porosity, and water saturation.

2021年12月1日 · This point is known as the critical concentration point in which quartz grains are still in contact with each other and clay particles completely fill in the pore spaces of the rock. It divides the entire domain of dispersed clay group into two subclasses named as shaly sand (grain-supported) and sandy shale (matrix supported).

2013年12月10日 · Wireline logs of four (4) wells from Apete field were studied to delineate petrophysical attributes of shaly-sand reservoirs in the field. Shale volume and porosities were calculated, water saturations were determined by the dual water model, and net pay was estimated using field-specific pay criteria.

2017年10月16日 · Most methods of working with thin bed shaly sand formations can be divided into three groups. The first group tries to increase the vertical resolution of the resistivity methods to the vertical...