DefinitionA rubber cup that has almost the same diameter as the inside diameter of tubing in a well, and used to swab a well. Swab cups are attached to swabbing tools and run on wireline or swab line into the well through the tubing. As they are lowered, the swab cups allow fluid in the tubing to flow past them. When the swab cups are raised, they seal against the tubing and force the overlying fluid up the tubing.
