Question

The coefficient of permeability by Packer for length greater than ten times the radius test is given by ________

(a) \(k=\frac{q}{2πh}log_{10} \frac{L}{r}\)

(b) \(k=\frac{v}{2πLh}log_{10} \frac{L}{r}\)

(c) \(k=\frac{q}{2Lh}log_{10} \frac{L}{r}\)

(d) \(k=\frac{q}{2πLh}log_{10} \frac{L}{r}\)

I got this question at a job interview.

Origin of the question is Well Hydraulics in portion Well Hydraulics of Geotechnical Engineering I

Answer 1

Right answer is (a) \(k=\frac{q}{2πh}log_{10} \frac{L}{r}\)

The explanation is: The coefficient of permeability k for L ≥ 10r is given by,

\(k=\frac{q}{2πLh}log_{10} \frac{L}{r}\)

where, q=discharge or constant rate of flow

r=radius of casing

h=differential head of water

L=length of portion of hole tested.