Extended Reach of Coiled Tubing
Nathan Wicks (Schlumberger), Jahir Pabon (Schlumberger)
Engineering Mechanics and Materials in the Oilfield
Tue 2:40 - 4:00
Sayles 105
It is becoming more common that oil and gas field developments involve the placement of long highly deviated or highly extended reach wells to access reserves more economically or in an environmentally acceptable manner. A significant number of these extended reach wells cannot be effectively intervened to total depth due to tubing string lock-up. If the horizontal section of the wellbore is sufficiently long, the axial compressive load conveying the tubing into the wellbore will cause the tubing to buckle. Buckling initiates in a sinusoidal mode and progresses to a helical mode. Once the tubing buckles helically, the string quickly locks-up due to increased normal forces and frictional interaction with the wellbore. In this talk, we motivate the study of buckling of coiled tubing, present classic analytical descriptions of tubing buckling, and describe current techniques used to extend reach of coiled tubing. We then introduce experimental and computational research undertaken to understand the mechanisms through which reach can be extended.