In petroleum engineering, TEM (true effective mobility), also called TEM-function developed by Abouzar Mirzaei-Paiaman, is a criterion to characterize dynamic two-phase flow characteristics of rocks (or dynamic rock quality). TEM is a function of

relative permeability In multiphase flow in porous media, the relative permeability of a phase is a dimensionless measure of the effective permeability of that phase. It is the ratio of the effective permeability of that phase to the absolute permeability. It can be ...

porosity Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measur ...

, absolute permeability and fluid

viscosity The viscosity of a fluid is a measure of its resistance to deformation at a given rate. For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. Viscosity quantifies the inte ...

, and can be determined for each fluid phase separately. TEM-function has been derived from

Darcy's law Darcy's law is an equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on results of experiments on the flow of water through beds of sand, forming the basis of hydrogeology, a branch of ...

for multiphase flow. :

\mathit =  \frac

in which

k

is the absolute permeability,

k_\mathit

is the relative permeability, φ is the porosity, and μ is the fluid viscosity. Rocks with better fluid dynamics (i.e., experiencing a lower pressure drop in conducting a fluid phase) have higher TEM versus saturation curves. Rocks with lower TEM versus saturation curves resemble low quality systems. TEM-function in analyzing relative permeability data is analogous with

Leverett J-function In petroleum engineering, the Leverett ''J''-function is a dimensionless function of water saturation describing the capillary pressure, :J(S_w) = \frac where S_w is the water saturation measured as a fraction, p_c is the capillary pressure ( ...

in analyzing capillary pressure data. Furthermore, TEM-function in two-phase flow systems is an extension of RQI (rock quality index) for single-phase systems. Also, TEM-function can be used for averaging relative permeability curves (for each fluid phase separately, i.e., water, oil, gas, ). :

\text = \frac = \frac

References

Petroleum engineering {{fluiddynamics-stub

See also

References