A traction tool has been built and tested as a part of the development of a long reach well concept. The application of the traction tool to assist the running of liners and sand screens in challenging wellbores is studied and the results and conclusions are described.
Full-scale testing of the traction unit prototype has demonstrated that it can deliver large axial forces to the string. A prototype tool for assisting during the completion phase of challenging wellbores is described, including the tool's measured performance from testing in casing.
The industry partners supporting the development work identified an opportunity to utilize the device to assist the completion operation to ensure that the target depth is reached.
Different scenarios where a traction device can provide a benefit include:
Buckling of the running string in extended reach wells
Insufficient available string weight in shallow reservoirs
Avoid rotating sand screens to reduce axial friction
The benefit of utilizing this tool is demonstrated by simulating the completion operation. Comparative well case studies are performed to study the completion operation, with and without the traction system included. A torque and drag model is used to estimate the mechanical forces present during the running of the completion string and these are compared to the buckling and load limits. Input parameters such as wellbore geometry, friction factors and completion string specifics are taken from relevant well examples. The operational performance for different positions of the tool in the running/completion string is also investigated.