Features and Advantages of Using Coiled Tubing Technologies
The peculiarity of coiled tubing (CT) using is that this 
technology is in many ways superior to conventional tubing used in well development. In particular, coiled tubing can easily penetrate horizontal and lateral wells without having to spend time assembling/disassembling the string.
For the first time such technology began to be used in the mid 50’s of the last century, but it became widespread only 30 years later. Currently, the number of CT units used in the global oil and gas production industry exceeds thousands of units.
The priority of using this type of equipment remains with Canada and USA, in our country coiled tubing technologies are just beginning to develop , however they have a very high growth potential and are prospectively in high demand.
Coiled Tubing Technology Application
The spectrum of downhole treatment with the use of coiled tubing is wide and varied enough, and in each case, the use of this technology gives the oil producing company a number of undeniable advantages. It looks like the following:
Field Research:
- The equipment is easily delivered to any point of the well;
- Uninterrupted communication with the run equipment is ensured.
Repair and Renewal Operations:
- Time is reduced: no need to assemble/disassemble the tubing;
- The well can be operated without killing, therefore, the reservoir properties of the productive zone and the bottom-hole zone are not affected;
- Reduces the time to prepare and deploy the necessary equipment;
- The possibility of uncontrolled release and pollution of the environment by process fluids and produced fluid is completely eliminated
Drilling
- Drilling operations can be carried out using oil solutions or refined products;
- The probability of uncontrolled well flowing is reduced to zero;
- It becomes possible to use downhole equipment to inform the operator about the drilling modes and optimize the well drilling processes;
- The efficiency of horizontal development increases.
In general, the use of coiled tubing significantly increases the safety of operations in high-pressure wells. In addition, a continuous string of coiled tubing allows for nonstop pumping down into the wellbore, making the work process much easier and faster.
Technological Process of Coiled Tubing
In general terms, the technology of coiled tubing does not look complicated. Pipes are selected depending on the nature of the work to be performed, and their diameter can vary from 19-114 mm. The tubing is coiled from a reel, which is located on the frame of the truck. The pipe passes through an injector, which creates the necessary force to move the tubing inside the well, taking into account the friction and wellhead pressure.
After that, the coiled tubing is guided through the preventer stack and into the casing or tubing string. The BHA of coiled tubing consists of a jet nozzle and a check valve, which is designed to supply nitrogen or other injected fluid. Fluid is diverted through a manifold and a nozzle line into a reservoir, which is routed through a preventer unit and into a casing or tubing string. The coiled tubing tip consists of a hydromonitor nozzle and a check valve, which is designed to supply nitrogen or other injected fluid. The fluid is discharged through a manifold and a connection line into a special tank.
Coiled tubing technology can be used for well cleanup after hydraulic fracturing: nitrogen shall be injected to wash proppant out of the fracture. Thanks to this technique, the inter-repair interval is considerably extended and the period of well return to production is reduced.
CT Equipment
Our company manufactures CT equipment that can be mounted on a truck chassis, semi-trailer or frame version. The reels for feeding the coiled tubing are equipped with a hydraulic drive, braking system and a pipe layer. A software control package, injectors and pressure control instruments can be included.