An exploratory well encountered three reservoir formations S1 (perfectly cemented) S2 (poorly cemented) and S3

Q. An exploratory well encountered three reservoir formations S1 (perfectly cemented), S2 (poorly cemented) and S3 (fractured). The Formation Factor (F) is governed by the equation 𝐹 = 𝑎𝜙^−𝑚, where ‘𝜙’ is the porosity and ‘m’ is the cementation factor. The constant ‘a’, linked to tortuosity is assumed to be 1 for all the formations. The log-log plot between Formation Factor (F) and porosity (𝜙) is shown.

Which one of the following represents the correct match of the formations with their respective plots?

(A) S1-P, S2-Q, S3-R	(B) S1-R, S2-P, S3-Q
(C) S1-P, S2-R, S3-Q	(D) S1-R, S2-Q, S3-P

Ans: S1-R, S2-Q, S3-P