One of the biggest problems facing mechanical "slickline" well servicing crews is the need to make judgemental decisions concerning the usability of wire. Miscalculation of wire condition can result in wire failures that can significantly impact economic efficiency with costly fishing operations. Premature replacement of still-useable wire to avoid the first scenario also affects operational costs, and therefore, in most cases does not offer a viable solution. Until recently, operators have had to rely on experience, "rules of thumb," visual inspection, and the "API Wire Twist Test" to determine wire integrity. These inspection methods have been limited in their capability to provide the information required to accurately determine wire condition.
This paper will present a new inspection concept that incorporates an existing, nondestructive material inspection technology into a new real-time method for determination of wire condition. The system, which employs eddy-current inspection methodology, can be used for several different applications and has the capability to provide information on various types of wire failure modes. Use of the system can:
* Ensure integrity of new wire as it is being spooled.
* Avoid costly replacement of still-useable 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.
In this paper, "wireline" will be used in the context of performing mechanical wireline services as opposed to mono-conductor or multi-conductor electric wireline used in cased or openhole logging services. There are two types of mechanical wireline currently in use; these are commonly referred to as; "slickline" and "braided line." Slickline is a single-strand wire that can be made of various carbon steel and stainless alloys and is available in varying lengths and diameters. Slickline lengths are generally between 15,000 to 30,000 feet (4,572 to 9,144 m), and the most popular outside diameters (OD) are .092, .105, .108, and .125 inches (2.34, 2.67, 2.74, and 3.18 mm).