The interconnected pore volume or void space in a rock that contributes to fluid flow or permeability in a reservoir. Effective porosity excludes isolated pores and pore volume occupied by water adsorbed on clay minerals or other grains. Background for multiple.
Articles › Engineering Bufret Lignende Oversett denne siden 16. The porosity of a rock is a measure of its capacity to contain or store fluids.
Expressed in terms of symbols, Eq. INTRODUCTION The most basic property of reservoir rocks is porosity (f) which allows the rock to store fluids (gas, oil, and water). State Water Survey Division.
Energy and Natural Resources. SWS Contract Report 351. EFFECTIVE POROSITY OF GEOLOGIC MATERIALS. FIRST ANNUAL REPORT by James P. Experiment absolute and effective.
It is frequently studied to represent the porosity of sediment or rock available. However, many intervals that have been traditionally thought of as shale are really silty shales or sandy shales. These may have sufficient porosity to store hydrocarbons that might flow.
This is especially true for gas, and many gas shales are silty shales with effective porosity. Other gas shales are mostly shale and gas is . Porosity is very important. Transportation of fluids is controlled mainly by connected pores. For intergranular materials, poorly to moderately well cemente the . That proportion of the total pore space in a rock which is capable of releasing its contained water. Clay, for example, may have a total porosity of or more, but little if any of the water contained in these pores may be release because of the retentive forces (e.g. surface tension) that hold it within the rock.
Both definitions account for the usual grain volume and hydrocarbon and capillary-water volumes seen in the porosity of nonshaly sands, and both models include volumes for the . Luttrell, and William E. The porosity is the percentage of the (reservoir) rock occupied by pores (typically 0-). The effective porosity value was about. Neutron logs are effected by all the hydrogen atoms in the rock and thus measure crystalline bound hydrogen (structural water), clay bound hydrogen . As discussed in Chapter 1.
When a sedimentary deposit is a mixture of various grain sizes this difference becomes larger, especially .