Used to place and recover wellbore equipment, such as plugs, gauges and valves, slicklines are single-strand non-electric cables lowered into oil and gas wells from the surface. Slicklines can also be used to adjust valves and sleeves located downhole, as well as repair tubing within the wellbore.

Slickline looks like a long, smooth, unbraided wire, often shiny, silver/chrome in appearance. It comes in varying lengths, according to the depth of wells in the area it is used (it can be ordered to specification) up to 35,000 feet in length. It is used to lower and raise downhole tools used in oil and gas well maintenance to the appropriate depth of the drilled well. In use and appearance it is connected by the drum it is spooled off of in the back of the slickline truck to the wireline sheave (a round wheel grooved and sized to accept a specified line and positioned to redirect the line to another sheave that will allow it to enter the device that allows the slickline to enter the wellbore while keeping the pressure contained and wiping the messy and sometimes hostile downhole fluids from the line. Slickline is used to lower downhole tools into an oil or gas well to perform a specified maintenance job downhole. Downhole refers to the area in the pipe below surface, the pipe being either the casing cemented in the hole by the drilling rig (which keeps the drilled hole from caving in and pressure from the various oil or gas zones downhole from feeding into one another) or the tubing, a smaller diameter pipe hung inside the casing.

When a shock tube lead fails under tension and the free end slaps against a hard surface. There is a known, but uncommon, failure mode that can lead to premature initiation. Where the lead that fires is a downline to a loaded hole the results can be catastrophic.

A 'Socket' is the remnant part of a blasthole remaining after firing.

Also referred to as a butt or bootleg.

The definition of a socket (South African regulation) is:

Any shot hole or any part of any shot hole, known not to be a misfired hole, which remains after being charged with explosives and blasted

A solution consisting of ammonium nitrate dissolved in water. For the manufacture of explosives the solution is ‘super saturated’. This means that the solution is made hot and allowed to cool without crystals forming.

The distance between blast holes and a row.

The difference between the spacing dimension and the burden dimension expressed as a ratio.

Breaking into fragments or small pieces.

The speed of sound varies with the medium it is travelling through as follows:

Air - 340 meters per second

Water - 1450 meters per second

Soft Rock - 3000 meters per second

Hard Rock - 5000 meters per second

Note that the speed of sound in rock is the 'seismic velocity' which is the speed that ground vibration travels.

A type of combustion which occurs without an external ignition source.

Multiple row blasthole pattern where each row is aligned directly behind the row in front.