Uses and
Limitations of Drillstring Tension and Torque Models for Monitoring Hole Conditions
16664
Brett, J.F.
Beckett, A.D.
Holt, C.A.
Smith, D.L.
Summary
This paper presents the results of the application of a tension/torque model
to directional wells drilled worldwide. The final inclination of the wells
ranged from 25 to 70 degrees, and the tension/torque model was effectively
used in these cases to aid in planning the directional program before spudding,
to monitor the wells during drilling, and to analyze particular drilling problems
after completion. The first set of examples represents the situations to which
the tension/torque model can be routinely applied and shows that the model
can effectively aid the well planner in selecting the best well path, drillstring
designs, casing program, and mud system before spudding. A second set of examples
shows how real-time monitoring of drilling conditions can he combined with
the model to develop a baseline so that deviations from expected behavior
can be analyzed and explained. Appropriate action can then be taken to remedy
problems before they become serious. A final set of examples shows how a tension/torque
model can be effectively used to determine the actual cause of a particular
drilling problem after a well is completed. Experience gained from postanalysis
of problems can be used to improve later operations. This paper also compares
field data with model predictions for a wide range of different inclinations.