Definition:
Lead Impression Block (see comment)
Subject Area 1:
A tool
Remarks:
LIB is a kind of tool which is used in fishing activities. Before running the overshot, the LIB is run and tags the top of fish. Since there is lead metal in the bottom of the tool, therefore the marks of the top of fish will be printed in the lead metal giving the information that on which side of well the fish is lying and more important without damaging the top of fish the exact depth will be known.