Conceptest: Permeability and Cone of depression

David McConnell, Department of Marine, Earth, and Atmospheric Sciences, North Carolina State University
Author Profile
This material is replicated on a number of sites as part of the SERC Pedagogic Service Project
Initial Publication Date: November 30, 2008

Question:

Two wells (A and B) are drilled into rocks that have the same porosity, but the rocks around well A have a higher permeability than these around well B. Suppose both wells are pumped at the same rate. Which statement is true?

a. Well A will have a larger cone of depression.

b. Well B will have a larger cone of depression.

c. The cone of depression will be the same for both wells.

Student Responses:

These responses were collected from students (mostly freshmen, non-majors) in multiple large Earth Science classes (60+ students) at an open-enrollment, Midwestern university. N=145 students on first attempt; 133 after peer instruction.

a. 39% of students selected this answer on their first attempt; 27% after peer instruction.

b. 53% of students selected this answer on first attempt; 71% after peer instruction. (correct)

c. 8% of students selected this answer on first attempt; 2% after peer instruction.

References and Notes: