Свернутый НКТ Reel Components, Mechanism & Производительность

Свернутый tubing is stored on large reels in the same manner as the flexible cable of a wireline unit. It is in essence a storage drum, designed to store the entire tubing string, and is an integral part of the CT Блок. These reel’s capacities come in sizes ranging from approximately 5000 to 25000 feet. The weight of the reel increases considerably with longer, larger diameter tubing. Example Reel Weights:

• Reel Without НКТ, 4080 kg (9000 lbs)
• Reel with 6400m or 21,000ft 11∕4″ НКТ, 14,970 kg (33,000 lbs)
• Reel with 4570m or 15,000ft 11∕2″ НКТ, 16,330 kg (36,000 lbs)

Свернутый НКТ Reel Components & Functions

 

 

Typical reel components, shown in Фигура 1, are as follows:

1. Storing and protecting the CT string (drum)
2. Maintaining proper tension between reel and injector head (reel drive system)
3. Efficiently spooling the CT string onto the reel drum (level wind system)
4. Circulating fluids with the drum rotating (swivel)
5. Application of protective coating or inhibitor on tubing string (tubing lubricator system)
6. Back-up depth measurement (reel mounted counter)

“Levelwind” Система (Фигура 2) Components include:

1. Drive chain/system (1)
2. Override motor (2)
3. Spooling head (3)

Reel Шарнир is mainly used on CT, with one end connected to coiled tubing, and another end to the surface manifold for pressurized rotary operation, as shown in Фигура 3:

Mechanism & Working Principal

The reel is supported on an axle and is rotated by a hydraulic motor through a chain drive. This drive system has a dual function: when uncoiling tubing, i.e. running into the well, the motor acts as a constant-torque brake, thus keeping the tubing to the gooseneck under tension.

When coiling, this drive system revolves the reel so as to coil the tubing under constant tension. The CT reel drive system itself is not used to lower or hoist tubing in the well, which is the purpose of the injector head.

To control the coiling process so that the tubing is correctly coiled upon itself, a winding (spooling) mechanism is synchronized with the rotation of the reel. This is provided with a manual override facility for finer adjustment.

The inner end of the coiled tubing is connected to the hub of the reel which incorporates a rotating joint. Fluid can be pumped through this joint and down the coiled tubing while the reel is stationary or in motion, and to any pressure up to the operating pressure of the coiled tubing itself.