Wireline tools are specialized tools used in the oil and gas industries, mineral exploration enterprises, and other fields to conduct technical procedures in vertical or horizontal shafts such as wells. A wireline tool typically consists of some type of line to which one or more instruments are attached at one end. Such instruments may be used in procedures such as drilling, data measurement and logging, retrieval of objects or samples, maintenance such removal of matter buildup in a shaft, and more.
Lengths of wirelines and materials from which wirelines are made vary greatly to suit a multitude of applications. Extensive length of wireline may be needed to deliver wireline tools to the locations at which they are to be used. Wirelines may be made from different types of stainless steels, carbon steel, and other alloys. Material choice for wireline will typically be made based on cost, as well as technical variables such as potential for corrosion and pitting, tensile strength, and other factors.
A rope socket, also known as a wireline socket, is used to attach an instrument or a chain of instruments to the wireline. To facilitate movement of the instruments and wireline through a fluid, a wireline stem, sometimes called a sinker bar, may be attached to the wireline. This serves a function similar to a lead weight that is attached to a fishing line to sink a fishing hook through the water.
Given the wide variety of tasks that are performed with wireline tools, numerous instruments are available. Due to the extreme nature of the environments where these tools are used, instruments included in wireline tools are often designed to withstand excessive heat and pressure for several hours at a time. The length of time for which they may be used is typically longer when the environment is less harsh.
There are a variety of instruments that are unique to wirelines. Hydraulic jars deliver a shocking jerk to the wireline. This jars the wireline or some other obstruction loose in the event that it should become stuck. An impression block may be used to take an impression of an object, thereby allowing it to be measured or possibly identified. It is often used to gather information to facilitate the planning of further action when an object must be retrieved or repositioned or when an obstruction must be cleared. Bailers of many different types may be used to pump or vacuum up debris and remove it from the shaft in order to clear obstructions or to retrieve material samples. Pulling tools are used to retrieve items such as other instruments that have been lost in the shaft.
Due to the wide variety and large number of applications in which wireline tools are used, custom tools may be developed to suit a particular need when suitable off-the-shelf products are not available. The design and manufacture of wireline tools, whether custom-made or standardized products, are governed by a number of industry standards and specifications depending on their application and where they are manufactured.