Lead Impression Block

General Description and Construction
The Lead Impression Block is made with a piece of sub stock.  With a tool joint box in the top and lugs welded on the outside circumference at the bottom to hold the lead.  It is placed in a form and molten lead poured around it.  When the lead cools, it is put in a lathe to make it smooth on the bottom and outer edges.

Use
The Lead Impression Block is used to make an impression of a fish when the shape or size of the fish is unknown and sometimes when it is not known what the fish is.

Operation
To run the Impression Block, make it up on the bottom of the string and go in the hole, touch bottom very lightly, and mark pipe at rotary to show where bottom is.  Then, pick up two or three feet.  Spud the string down very rapidly and catch it on the mark indicating where you tagged bottom.  This should give you a good impression of the fish.  If possible, run a set of Bumper Jars above the Impression Block.  This will help get a better blow down.

Don’t every try to rotate an Impression Block and don’t try to make more than one impression.
If a drain sub is readily available, run it above the Impression Block because sometimes the fish will close the hole in the bottom and cause a wet string while pulling out of the hole.

Sometimes it is necessary to rerun an Impression Block.  The previous impressions must be marked so they will not confuse the second ones.  A good way to do this is by putting indentations around the previous impressions with a nail and hammer, deep enough that they won’t be destroyed.

If an Impression Block is in pretty bad shape, it is recommended to rerun it first.  Before you rerun one, check to be sure the lead is not coming loose.