In one possible implementation an in-situ property determination system includes a displacement tool configured for use in a wellbore. The displacement tool includes four or more pads symmetrically located about an axis of the displacement tool, with each pad having a contact surface configured to contact a wall of the wellbore. The four or more pads can extend from a first position proximate an outer surface of the displacement tool to a second position in contact with the wall of the wellbore such that the four or more pads deform the wellbore into an at least approximately circular cross section. The system also includes a recordation device to record force displacement information associated with extending the four or more pads from the first position to the second position.