What is slickline? Possibly the best way to get a start offshore.

I remember in the earlier days of my offshore adventures wondering what exactly offshore slickline jobs were.  Having now worked directly with slickline for a number of reasons on several projects, I have a good working understanding of what they do and why they’re doing it.  And it turns out that it may well be one of the best routes into the industry, with the bonus of also being a very progressive one.  Links to slickline companies can be found at the bottom of this pageand links to offshore drilling jobs and offshore platform jobs can be found HERE.  But do keep reading on, because knowledge is king and every little helps when you’re pushing yourself towards new career prospects.

The Slickline Crew

Slickline is a pretty complex process involving a minimum of two on each shift, and sometimes three.  The crew will consist of a supervisor, an operator, and sometimes a trainee.  Because of the complex and multi-skilled nature of slickline, it can take a number of years to reach supervisor level due to the responsibility of the position, but training and competencies are on-going at every level so the opportunities for career expansion are great.

Basic slickline operations

So what is slickline?  To simplify the process, make an image in your mind of an oil or gas well that has already been drilled and completed.  That is, a rough bare hole has been drilled into the ground and then a lining of steel tubing has been lowered into that hole and has been cemented into place by squeezing cement round the back of the pipe.  We now have a well.  It’s just a hole in the ground though, so now along come your well Completions Engineers and using the rig they lower thousands of feet of production tubing into that well and it is locked into place against the outer tubing (casing).  So the picture in your mind should now be a very long steel pipe inside another.  Much like this handy drawing from Schlumberger.

HIW_well_completion_1
A basic completed oil well

So, in that ‘completed’ inner tubing (production tubing) there are areas to land off tools and leave them there, perhaps thousands of feet down the hole, and they are called nipples.  There are also ‘pockets’ in the side of the tubing to insert and retrieve valves.  We’ll leave the complexities of well completions there for now though, as this is about slickline.

So let’s imagine that the oil company owning the well wants to know the pressure and temperature close to where the oil flows, for whatever reason.  They may call on a slickline company to come along and lower a battery powered pressure / temperature sensor gauge on a 0.125″ diameter wire thousands of feet into that hole, and then deliberately leave it there locked in a nipple profile to be retrieved after a few days of collecting data.  Once brought back to surface, the data could be collected and we have a happy oil company with new data.  This is one example of thousands of scenarios slickline could be involved in.

Offshore-Wireline-Unit-Spooling
A slickline unit with the spool of wire

In effect, slickline is what it says on the tin: a slick piece of wireline thousands of feet long.

Slickline tools

The list of what slickline is capable of is endless really, and is enhanced by another endless list of third-party tools provided by oil service companies that can be ran on the end of the wire.  Both work side by side to achieve whatever goals the oil companies have set out.  The tools ran may include:

  • Stem
    • Small diameter ‘weight bars’ used to add weight to the tool-string and to add inertia to jarring (hitting) operations.
  • Spang jars
    • Think of a sliding hammer where two tubes are interlocked and if knocked up or down could produce a resultant impact force to set or retrieve tools.
  • Power jars
    • These are used to provide very big down-hole hits, and usually work with the aid of springs to add force.
  • Plugs
    • Nipple plugs (set in the nipples at various points in the completion)
    • Bridge plugs (set at any point on a tubing joint to isolate the well)
    • Hanger plugs (set at the top of the well in the tubing hanger)
  • Gauges
    • Battery powered pressure / temperature / flow / seismic, mostly hung off gauge hangers in nipple profiles.
  • Tubing punches
    • Literally for punching a small hole in the tubing
  • Kick over tools
    • Used to insert and retrieve equipment from those side pockets, such as gas lift valves.
  • Cameras
    • Battery powered
    • Pressure activated

Honestly, I could go on, but the possibilities are too many to mention.  Throw in the ability to set and retrieve safety valves, sleeve shifting tools, fishing tools for retrieving stuck objects, specialist tools for deviated wells that go off at a high angle, and you get the picture.

Complex?  Absolutely.  Underestimated?  Most definitely.  But as I posited earlier, slickline can lead on to bigger and better things.  Throughout the industry ex-slickliners have become offshore Well Service Supervisors, and for good reason.  Their responsibilities see them accrue a very wide knowledge of well operations and the processes involved in well management and well isolation, so supervising the overall process becomes a natural progression.

Links to slickline jobs

As promised, I’ve included links to companies that deal in slickline operations for the same reason I provided links to general offshore jobs.  Karma.

Click the Offshore Insider logo at the top to jump to my homepage, which has plenty of other articles covering many other aspects of the oil industry, plus more role specific links to offshore jobs for people with experience or without.

Click the contact form on the Offshore Insider homepage or at the top of this page and send me a message for offshore CV writing services from an experienced industry insider.

 

 

 

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