CT Jobs

CT Jobs refer to well workover operations involving coiled tubing reeled on special units. Essentially, coiled tubing allows state-of-the-art well workover, and its application ensures highest level of operational and environmental safety during operations.

In 2014, FJV was chosen the winner of an award from Intervention & Coiled Tubing Association (ICoTA) - «Best Company in the Sphere of CT Technologies Application in Russia and CIS»

Wellbore cleanout and well completion

Wellbore cleanout and well completion

CT wellbore cleanout is a widespread practice that ascertains the removal of hydrate, paraffin, proppant and sand plugs; helps avoid the fracturing troubles and allows to quickly put a well on production.
Frac port milling & well completion following multistage fracturing
Frac port milling & well completion following multistage fracturing
As of today, well completion following multistage fracturing is one of the most in-demand CT technologies.

During multistage fracturing, an assembly is deployed into a horizontal wellbore to isolate a required number of zones cut off by packers in the reservoir. Fracturing ports are then opened in continuous succession to perform hydrofracturing.

CT jobs following multistage fracturing include:
1. Proppant removal from the completion assembly;
2. Frac port milling (balls and seats);
3. Flow stimulation.
The use of separators installed above a motor assembly ensures proppant cleanout and frac port milling in one trip.

As a general principle, foam-gel compositions are used in wells with abnormal low reservoir pressure.

Foam-gel compositions consist of polymeric compounds and a breaker. When pumped in, the solution is nitrified. As a result, the foam system features low leakoff into the formation even in case of disastrous lost circulation (no return). Upon gel breakdown, its viscosity is comparable to that of water.
CT logging
CT logging
Coiled Tubing can be applied to facilitate on-line well logging with isolated survey tools (CT with wireline) at the following wells:
- Directional sidetracks and/or highly deviated wells;
- Horizontal wells;
- Flowing wells with high flow rates.
Moreover, CT application allows the user to collect well data (bottomhole pressure, inclination and drift angles, temperature) and conduct well testing.
Abrasive perforation
Abrasive perforation
The technology is based on the kinetic jet energy of sand-gel suspensions formed in the nozzles of a sand-jet perforator. The high-velocity slurry has an abrasive effect, which cuts through the casing, cement and rocks and makes perforations of various orientations. The slurry is pumped into CT at high pressure by a pumping unit.

Advantages:
- Technological safety;
- No cracks in cement rock;
- No compression of the perforation tunnel walls and no plugging of the tunnels with explosion products;
- Large completion areas and extensive caverns.
Bottomhole treatment
Bottomhole treatment
The treatment of wells with large inhomogeneous zones of carbonate reservoir poses certain challenges.

Acid is only capable of treating layers/beds of high permeability, thus every “new” acidizing job reams out the existing tunnels and caverns.

Therefore, CT methods are combined with deviation technologies, such as:
- Massive foam acidizing
- Gelled acid treatment
- Self-diverting acid compositions
- Thermal foam acidizing
- Auto-decomposing synthetic fibers and gelled acid
- Organic compounds in bottomhole treatment.
Production tubing & production string jetting
Production tubing & production string jetting
Jetting tools are used to remove clogs, scale, cement, paraffin, resins and other sediments. They have proved efficient in the cleanup of:
- Production tubing
- Perforation zones
- Open hole
- Slotted wire-wrapped filters
- Slotted liners
- Safe valves
Multilateral well treatment

Multilateral well treatment

Multilateral well treatment is performed by means of a “CT orienting complex”.

The complex is directed by the fluid flow and has adjustable rotation angle (150, 300, 450) and bend (150).

Upon entering a lateral hole, the instrument gives a pressure drop indication of inclination.
Acid jet drilling
Acid jet drilling
The acid jet drilling technology involves creating several horizontal sidetracks in the production range by dissolving carbonaceous rock with hydrochloric acid. The operation is performed by a standard CT operators crew. The pumping unit and the tank farm required are identical to those in the acidizing job.

Advantages:
- Target treatment of selected sublayers;
- Development of new drainage zones due to the intersection of uninvaded fractured zones;
- Delivery of the acid to uninvaded zones of the productive formation.
What makes the technology so convenient and accessible?
- The operations can be performed by a CT crew only;
- The job is performed without pulling the equipment out of the hole;
- Several sidetracks can be created in one trip.
CT Fishing jobs
CT Fishing jobs
- Emergency jobs with a hydraulic jar;
- Application of hydraulic release overshots and spears;
- Retrieving wireline and logging cable («a fishing rod», hydraulic pliers);
- Removing junk and restrictions (bailers, magnetic impression blocks, ball catchers);
- Performing jobs in overbalanced wells;
- Performing jobs in horizontal wells.
Cementing

Cementing

CT cementing jobs involve polymer, silicate and organosilicon compositions, as well as resins and microcements. Coiled tubing facilitates thru-tubing mill-assisted plugging and drilling out of cement bridges.
Pipe cutting
Pipe cutting
Whenever required, a stuck heavy-weight drillpipe or tubing can be cut off above the stuck point by means of a hydraulic pipe cutter. The pipes with 73 mm (2 7/8”), 89 mm (3 ½”), 102 mm (4”) and 114 mm (4 ½”) OD can be cut off.

Advantages:
- There is no negative effect on the production string;
- Notubingdeformationinthecut-offarea facilitates the following fishing jobs.