impression block
impression block
[im′presh·ən ‚bläk] (petroleum engineering)
A block with wax or lead on the bottom run into a well and allowed to rest on a lost tool or other object so that an examination of the resultant impression is revelatory concerning the size, shape, or position of the object.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.