Any work associated with using a wire to transport a tool into an oil or gas well is called wireline logging or wireline work. There are two types of wireline: slick (non-electric) and braided electric line. Slick line is used when placing tools in the well that operate mechanically and do not need electricity to activate. This is simple and inexpensive and looks like a straightened coat hanger wire. Braided electric line is used for open hole logging (tools used to measure rock and fluid properties in a new well), perforating (shooting holes in the casing to allow the inflow of gas and liquids), measuring pressures or flow rates in the wells and many other operations. Braided line is stronger and can carry heavier tools into a well than can slick line. It looks like a cable made up of many strands of very fine wire. Companies such as Schlumberger, Baker Hughes. and Halliburton supply this service.