The Rebco A Impression Block is a diagnostic tool used to capture a physical imprint of an unknown obstruction encountered within the tubing string. The tool body houses a cast lead insert secured in place by retention pins passing through the steel housing, both to hold the lead in position during the run and to prevent loss of the lead face if it is partially displaced by contact with the obstruction downhole. The lead surface, being significantly softer than steel, deforms permanently on contact with any harder material it encounters at the bottom of the well, recording the three-dimensional shape, relative size, surface texture, and angular orientation of whatever the tool has touched.

This information is critical because many downhole fishing operations involve contacting an obstruction whose exact nature, orientation, and condition are completely unknown at the surface. A well-executed Impression Block run can reveal whether the top of the fish is a clean, flat fishing neck, indicating a standard pulling tool will engage it, or whether it is damaged, crushed, rotated, or positioned at an angle, requiring a specialized recovery tool. It can also identify entirely different obstructions: dropped hand tools, failed shear pin fragments, partially set plugs, or foreign objects that entered the well during a previous operation.

To obtain a useful impression, the tool should be run without a knuckle joint immediately above it. Angular movement between the Impression Block and the tubing axis will introduce a false tilt to the imprint, misrepresenting the fish's actual position. The tool is lowered gently onto the obstruction, and a single, controlled downward-jar blow is applied; a single clear impact produces a clean image. Multiple jar blows create overlapping, ambiguous impressions that are difficult to interpret. The lead face must be prepared before each run: smooth and flat, with no pre-existing marks. Rebco supplies lead filler blocks and a pouring ladle to allow field re-pours of the lead face between runs. The melting point of lead (Pb) is 327.5°C / 621.5°F. Always exercise appropriate thermal safety precautions during re-pours.

Available in standard threaded connections, ¾"–6⅝" OD. Custom sizes available on special order.

Important: Run the Impression Block without a knuckle joint immediately above it. Angular play at that connection will tilt the lead face and produce a false impression. Run one downward jar blow only; additional blows will overlay the image, making it unreadable. Prepare the lead face fresh before every run.

How to Order: Part Number is 10800x.xxx (0 prefix for ODs less than 1.00"). All Impression Blocks are part-numbered by OD to 3 decimal places ±.002". Metric prefix: 10801. Specify lead filler blocks (Part No. 108081 or 108082) and pouring ladle separately if required.