Abstract The structural integrity and predictable usability of slickline wire has perplexed wireline crews since wireline services were first developed. Miscalculation of wire condition can result in wire failures and costly fishing operations; however, the available alternative--premature replacement of still-usable wire to avoid the first scenario - also increases operational costs, especially when the ewer corrosion- and embrittlement-resistant nickel and cobalt alloy wires that are commonly used in H 2 S 2 CO 2 , and hot chloride environments are involved. These wires often are ten times as costly as carbon steel and stainless alloy wires, and in most cases, early replacement is not economically feasible. Until recently, operators have had to rely on experience. "rules of thumb, " visual inspection and destructive tests to determine wire integrity. However, these methods could only provide spot checks; none have been capable of accurately assessing the condition of the ntire length of spooled wire. This paper will review currently-used inspection procedures and a concept that incorporates an existing, nondestructive material inspection technology into a real; time method that can provide the information to determine ire condition over its entire length. Use of the system can: Evaluate integrity of new wire as it is being spooled onto the reel. Avoid costly replacement of still-usable wire. Facilitate general wire-life assessment. Inspect wire during critical service operations where well environment or operating conditions can cause rapid degradation of the wire. Test and field operational history will be used to illustrate the capabilities and significance of the system. Introduction Slickline is a single-strand wire that can be made of various carbon steel, stainless alloys, and more exotic nickel and cobalt-based alloys and is available in varying engths and diameters. Slickline lengths are generallybetween 15,000 and 30,000 feet [4,572 to 9,144 m], and the most popular outside diameters (00) are .092, .105, 108, and .125 inches [2.34, 2.67, 2.74, and 3.18 mm]. "Braided line," "mono-conductor," or "multi-conductor" electric wireline consist of braids or multiple strands of maller-OD wire, which are also available in various arbon steel, stainless and more exotic alloys in varying lengths and diameters. Braided-line and mono-conductor ine lengths are generally between 15,000 and 25,000 feet [4,572 to 7,620 m] with outside diameters of3116- Or 7/32inch [4.76 or 5.56 mm].. Multi-conductor line lengths are generally between 15,000 and 25,000 feet [4,572 to 7,620] with outside diameters of 7/16- or 15/32-inch [11.11 or 11.90 mm]. Typical Wireline Operation In a wireline operation, tools are attached to the end of a wire and lowered into the wellbore. Once the tools reach their desired depth, they are manipulated in a series of upward and downward motions to perform the desiredoperation. The wire is stored on a reel in a truck or skid and is generally run through or around a counter wheel and several sheaves (Figure 1). The counter wheel is used to easure the length of the wire deployed into the well. At least two sheaves are used to move the wire from a horizontal to vertical position in order to lower tools positioned on the end of the wire into a vertical wellbore.