What is Wireline / Slickline and how it works?
Wireline is one of the methods of deploying various down-hole tools into a well. Very often, it is called “ Wireline” and may represent a lot of different services, such as production logging ( PLT), memory gauge logging, cement bond logging (CBL), heavy fishing, plug setting and many more.
How does wireline work and what two distinct types of wireline exist? A cable on a reel on the surface is used to lower the tools to the wellbore. Two major types of wire are used: Slick Line and Electrical Line (E-Line). Slick Line is a standard cable wire that is used to lower tools down-hole and/or retrieve tools and equipment. Electrical Line is a cable that can be utilised to lower the tools and transmit data to the surface and to the tools deployed.
While Slick Line is mainly limited to ‘mechanical' operations only, E-Line can do the Slick Line job and can also help to evaluate (log) the formation, when the data must be sent to the surface. E-Line is a more value-added deployment method, as it covers both requirements, i.e. it can intervene on a mechanical level and collect data about well conditions too.
As a conveyance/deployment method, wire-line is used in a number of areas, starting from basic down-hole jobs to milling, as part of a well intervention programme. In highly deviated or horizontal wells, a tool called a wire-line tractor is used when the wire cannot progress any farther in the horizontal section. The tractor pulls the wire-line forward. In various applications, wire-line tractors have resulted in significant efficiency gains when compared with other conveyance methods, such as coiled tubing or snubbing. Onshore, wire-line units are truck-mounted, whereas, in offshore applications, the units are skid-mounted and can be installed on and removed from a drilling rig on a lift-boat fairly efficiently and quickly.