Porosity of a material is defined as that fraction of the bulk volume of this material that is not occupied by the solid framework of the material.In oil reservoirs,the porosity represents the percentage of the total space that is available for occupancy by eighter liquids or gases.It determines the storage capacity of the sand and is generally expressed on a percentage basis or as a fraction or a decimal.

One may distinguish two types of porosity,namely,absolute and effective:

Absolute porosity is the percentage of total void space with respect to the bulk volume regardless of the interconnection of the pore voids.

Effective porosity is the percentage of interconnected void space with respect to the bulk volume.

Grain volume methods:In these methods the consolidated sample is solvent extracted and dried;the bulk volume is determined eighter by the displacement of a liquid which does not penetrate the sample or by saturating the sample and volumetrically displacing a suitable liqu

Absolute Porosity Measurement:In the determination of absolute porosity,it is required that all nonconnecting as well as interconnecting pores be accounted for.

Bulk volume determination:The bulk volume of the extracted and dried samples may be determined by volumetric displacement of mercury.

Titration method: Another procedure for saturation determination makes use of the titration method.

Methods for the determination of reservoir fluid saturations in place consist in analyzing reservoir core samples for water and oil,the saturation in gas being obtained by difference since the sum of the saturations in the three fluids is equal to unity.

Per cent porosity=100x(pore volume/bulk volume)

Loss of weight method:The measurement of the grain volume of a core sample may also be determined by the loss in weight of a saturated sample plunged in a liquid.

It is obvious that the percentage of porosity may be calculated from such data by use of eighter of the two following relationships:

Some common words found in the essay are:
Measurements Grain, Thornton Marshall, POROSITY Porosity, SATURATIONS Methods, Taylor1938 Titration, Horner1944 Loss, Yuster Levine, Dean Stark, Locke Bliss1950, Porosity MeasurementIn, bulk volume, capillary pressure, core samples, pressure curves, loss weight, capillary pressure curves, retort method, fluid saturation, fluid saturation determinations, porosity percentage, absolute porosity, percentage total, space respect bulk, void space respect, respect bulk volume,
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