Talk:Archie's law

This article is rated Start-class on Wikipedia's content assessment scale. It is of interest to the following WikiProjects:

Geology Mid‑importance This article is within the scope of WikiProject Geology, an attempt at creating a standardized, informative, comprehensive and easy-to-use geology resource. If you would like to participate, you can choose to edit this article, or visit the project page for more information.GeologyWikipedia:WikiProject GeologyTemplate:WikiProject GeologyGeology Mid This article has been rated as Mid-importance on the project's importance scale.

I think the equation should read:

${\displaystyle C_{t}=aC_{w}\phi ^{m}S_{w}^{n}}$

or

${\displaystyle R_{t}={\frac {aR_{w}}{\phi ^{m}S_{w}^{n}}}}$

where ${\displaystyle a}$ is the coefficient of tortuosity.

Also, it might be better to define Archie's formation factor as:

${\displaystyle F={\frac {a}{\phi ^{m}}}={\frac {R_{t}}{R_{w}}}}$

Where Rt is the resistivity of the water saturated formation and Rw is the resistivity of the water inside that formation. There is no article for Formation factor so it would be a good idea to define it more broadly in this article. 38.100.75.194 (talk) 17:03, 22 February 2010 (UTC)Reply

Thanks for your suggestions. I have incorporated them. Berland (talk) 14:31, 4 March 2010 (UTC)Reply

I think that the first equation should read:

${\displaystyle C_{t}={\tfrac {1}{a}}C_{w}\phi ^{m}S_{w}^{n}}$

if ${\displaystyle a}$ is really the tortuosity factor found elsewhere. This is consistent with a conductivity that decreases as tortuosity increases and also with the second equation above (assuming ${\displaystyle R_{t}}$ is ${\displaystyle {\tfrac {1}{C_{t}}}}$. Reference is also been made to a "lithology factor", but it is not clear that this is the same thing as tortuosity. Mrsylvestre (talk) 10:05, 21 March 2010 (UTC)Reply

The equation in the article is already like you suggested. I could not find 'lithology factor' in the article, but I guess it has to be just another name for 'a', so I added it to the list of possible names. --Berland (talk) 10:22, 22 March 2010 (UTC)Reply