In what year did Gus Archie first publish his equation for calculation of water saturation?

In what year did Gus Archie first publish his equation for calculation of water saturation?

• A. 1939
• B. 1950
• C. 1960
• D. 1942

Answer: (D)

The idea being tested is when the foundational relationship linking rock resistivity to water content was first introduced. Gus Archie showed that in clean sandstone, formation resistivity relates to water saturation through a simple empirical form, enabling Sw to be calculated from Rt, porosity φ, and water resistivity ρw using constants a, m, and n. This breakthrough was published in 1942, establishing the original method for estimating water saturation from resistivity data. The later years brought refinements for more complex rocks, but the initial publication date of this fundamental equation is 1942.

The idea being tested is when the foundational relationship linking rock resistivity to water content was first introduced. Gus Archie showed that in clean sandstone, formation resistivity relates to water saturation through a simple empirical form, enabling Sw to be calculated from Rt, porosity φ, and water resistivity ρw using constants a, m, and n. This breakthrough was published in 1942, establishing the original method for estimating water saturation from resistivity data. The later years brought refinements for more complex rocks, but the initial publication date of this fundamental equation is 1942.