Rotary controlled system for directional and horizontal drilling.
Rotary controlled system is the drilling equipment, which is suitable for drilling directional, horizontal and multilateral wells with extremely large waste from the vertical, the exact wiring of the wellbore and opening of complex reservoirs and reservoirs with unconventional reserves, and for drilling on the continental shelf, the Arctic, and complex geological conditions.
Rotary controlled system is the current generation of drilling equipment, which is suitable for drilling directional, horizontal and multilateral wells with extremely large waste from the vertical, the exact wiring of the wellbore and opening of complex reservoirs and reservoirs with unconventional reserves, and for drilling on the continental shelf and the Arctic.
Rotary controlled system consists of flexible joints, stabilizer, control unit and the deflecting unit. Part of the deflecting unit includes the chisel.
Fig. 1. Appearance of rotary-controlled system for drilling wells
When using rotary managed system deflecting force on the bit is created directly in the process of rotation of the drill string, and control the deflecting unit occurs from the surface.
Currently apply two concepts rotary managed system: a reject bit (“push-the-bit”) and with the direction of the bit (“point-the-bit”). In the system with a deviation of a bit “push the bit” orientation rotary controlled system in the desired direction is produced by pressing a special pull-out shoes (blades) rotary managed system on the wall of the well.
In the system with the direction bit “point-the-bit” is used for internal bending deflection of the projectile from the current to the borehole axis and changing the direction of drilling. In this system, the bending point is in a heavy weight drill pipe system directly over the chisel. System with the direction of the bit change the well path by changing the angle of the end face of the drilling tool relative to the well bottom. Trajectory changes in the direction of the bend. The orientation of the bending is done with the help of servo motor.
– obtaining higher quality wellbore
– enables you to drill long – more than 10 km of horizontal trunks
– reducing the risks of complications and accidents,
– allows you to control the trajectory of well drilling,
– wide range of applications,
– the possibility of drilling in difficult geological conditions
– smoother path (less tortuosity) wells compared to downhole mud motors,
– possibility of use in wells with high reservoir temperatures and pressures, which limited the use of downhole drilling motors,
– increase the drilling rate by reducing friction and better cleaning of the barrel from the sludge
– improves the removal of cuttings,
– the use of a rotary controlled system greatly increases the efficiency of development of oil reserves.