TEM-function

• Comment: Ideally the first sentence (at at least the first paragraph) should give a clear, basic overview of the topic - right now "TEM-function" isn't even mentioned in the first paragraph. You can split the history off into a different section if you want, or just place it later in the article. LittlePuppers (talk) 16:26, 30 May 2020 (UTC)

• Comment: Some parts (e.g. "Traditionally, it had been assumed by reservoir engineers..." needs some fixing. Eumat114 formerly TLOM (Message) 03:45, 10 May 2020 (UTC)

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TEM (True Effective Mobility), also called TEM-function, is a criterion to characterize dynamic fluid-flow characteristics of rocks. TEM is a function of Relative permeability, Porosity, absolute Permeability and fluid Viscosity, and can be determined for each fluid phase separately. TEM-function has been derived from Darcy's law for multiphase flow.

$TEM={\frac {kk_{\mathit {r}}}{\phi \mu }}$

in which k is the absolute Permeability, kr 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 analyzing Capillary pressure data.

Also, TEM-function can be used for averaging relative permeability curves (for each fluid phase, separately (i.e., water, oil, gas, CO2)).

${\text{Average kr}}={\frac {\sum _{i=1}^{n}TEM_{i}}{\sum _{i=1}^{n}({\frac {k}{\phi \mu }})_{i}}}={\frac {\sum _{i=1}^{n}({\frac {kk_{\mathit {r}}}{\phi \mu }})_{i}}{\sum _{i=1}^{n}({\frac {k}{\phi \mu }})_{i}}}$