Editing Wireline (cabling) (section)

==Pressure control during wireline operations==
The pressure control employed during wireline operations is intended to contain pressure originating from the well bore.  During open hole electric line operations, the pressure might be the result from a well kicking.  During cased hole electric line, this is most likely the result of a well producing at high pressures.  Pressure equipment must be rated to well over the expected well pressures.  Normal ratings for wireline pressure equipment is 5,000, 10,000, and 15,000 pounds per square inch. Some wells are contained with 20,000 psi and 30,000 psi equipment is in development also.

===Flange===
A flange attaches to the top of the Christmas tree, usually with some sort of adapter for the rest of the pressure control.  A metal gasket is placed between the top of the Christmas tree and the flange to keep in well pressures.

===Wireline valve===
A wireline control valve, also called a wireline blow out preventer (BOP), is an enclosed device with one or more rams capable of closing over the wireline in an emergency.  A dual wireline valve has two sets of rams and some have the capability of pumping grease in the space between the rams to counterbalance the well pressure.

===Lubricator===
Lubricator is the term used for sections of pressure tested pipe that act to seal in wireline tools during pressurization.
As stated it is a series of pipes that connect and it is what holds the tool string so operators can make runs in and out of the well. It has valves to bleed off pressure so that you can disconnect it from the well and work on tools, etc.

===Pump-in sub===
the Pump-in subs (also known as a flow T) allow for the injection of fluid into the pressure control string.  Normally these are used for wellsite pressure testing, which is typically performed between every run into the well.  They can also be used to bleed off pressure from the string after a run in the well, or to pump in kill fluids to control a wild well.
[[File:Wireline Grease-head.JPG|thumb|Wireline Greasehead used for pressure control]]

===Grease injector head===
The grease injector head is the main apparatus for controlling well pressure while running into the hole.  The grease head uses a series of very small pipes, called flow tubes, to decrease the pressure head of the well.  Grease is injected at high pressure into the bottom portion of the grease head to counteract the remaining well pressure.

===Pack-off===
Pack-off subs utilize hydraulic pressure on a two brass fittings which compress a rubber sealing element to create a seal around the wireline.  Pack-offs can be hand pumped or compressed through a motorized pumping unit.
[[File:Pack-off.png|thumb|Wireline Roller-top Pack-off]]

===Line wiper===
A line wiper operates in much the same way as a pack-off sub, except that the rubber element is much softer.  Hydraulic pumps exert force on the rubber element until a light pressure is exerted on the wireline, cleaning grease and well fluid off the line in the process.

===Quick test sub===
A quick test sub (QTS) is used when pressure testing the pressure control equipment (PCE) for repetitive operations. The PCE is pressure tested and then broke at the QTS afterward to avoid having to retest the entire string. The PCE is then reconnected at the QTS. The QTS has two O-rings where it was disconnected that can be tested with hydraulic pressure to confirm the PCE can still hold the pressure it was tested to.

===Ball-check valve===
If the wireline were to become severed from the tool, a ball check valve can seal the well off from the surface.  During wireline operations, a steel ball sits to the side of a confined area within the grease head while the cable runs in and out of the hole.  If the wireline exits that confined area under pressure, the pressure will force the steel ball up towards the hole where the wireline had been.  The ball's diameter is larger than that of the hole, so the ball effectively seals off pressure to the surface.

===Head catcher===
A head catcher (also called tool catcher) is a device placed at the top of the lubricator section.  Should the wireline tools be forced into the top of the lubricator section, the head catcher, which looks like a small 'claw,' will clamp down on the fishing neck of the tool.  This action prevents the tools from falling downhole should the line pull out of the rope socket.  Pressure is applied to the head catcher to release the tools.

===Tool trap===
A tool trap has the same purpose as a head catcher in that it prevents the tools from inadvertently dropping down the hole. This device is normally located just above the well control valves, providing protection to these important barriers from a dropped tool. The tool trap has to be functioned Open in order to allow the tools to enter the well, and is normally built to allow tools to be recovered through the tool trap even when it is in the Closed position.

===Quick-connect sub===
A subassembly device that is bolted to the top of the BOP stack that is designed to eliminate traditional bolt-flanges to connect lubricator heads and utilize tapered-wedge and lock ring designs. This allows the same security of traditional pressure control connections but a significant time savings component.