What is the difference between primary and secondary porosity?

Primary porosity is the original porosity of the rock when it formed, and secondary porosity is the pore space created by subsequent processes such as fracturing.

What is the difference between primary and secondary permeability?

Fracturing produces secondary permeability meaning it was created AFTER the rock in question was formed. The fractures create new void spaces in the rocks which allow fluids to move into the voids. Primary permeability occurs DURING the compaction process when the original materials are forming the rock.

What is primary porosity in geology?

Primary porosity describes the pore spaces between grains that are formed during depositional processes, such as sedimentation and diagenesis. Secondary porosity is formed from postdepositional processes, such as dissolution, reprecipitation, and fracturing.

What are the examples of secondary porosity?

Secondary porosity is formed from postdepositional processes, such as dissolution, reprecipitation, and fracturing. Fractures, root channels, and animal burrows are some examples of secondary porosity. Total porosity is the sum of the primary and secondary porosities.

What is secondary porosity?

Secondary porosity is porosity that has developed after the rock has formed. It can include fracture porosity — space within fractures in any kind of rock. Some volcanic rock has a special type of porosity related to vesicles, and some limestone has extra porosity related to cavities within fossils.

What is dual porosity?

1. n. [Well Testing] A rock characterized by primary porosity from original deposition and secondary porosity from some other mechanism, and in which all flow to the well effectively occurs in one porosity system, and most of the fluid is stored in the other.

What is difference between porosity and permeability?

More specifically, porosity of a rock is a measure of its ability to hold a fluid. Permeability is a measure of the ease of flow of a fluid through a porous solid. A rock may be extremely porous, but if the pores are not connected, it will have no permeability.

How do you define porosity?

Porosity is defined as the ratio of the volume of pores to the volume of bulk rock and is usually expressed as a percentage.

How do you find secondary porosity?

Secondary porosity is classically estimated from well logs as the difference of total density porosity minus total sonic porosity φf ≅ φd – φs. It is applicable to either carbonate rocks or clastic sandstones that may or may not contain clays.

What is dual porosity dual permeability?

The recent dual-porosity/dual-permeability approach uses Darcian flow through both matrix and fractures. Results of a series of numerical runs are presented in order to show the behavior of the new model for a range of different flow parameters, such as matrix permeability, fracture width, and fracture spacing.

What is dual permeability?

Dual-permeability models assume that the complete porous media system can be represented by two different interacting subsystems: the matrix and the fracture pore domain. For some soils like fractured clays, the fracture domain may be empty, which makes its physical behavior differ significantly from capillary flow.