Method of determining when tool string parameters should be altered to avoid undesirable effects that would likely occur if the tool string were employed to drill a borehole and method of designing a tool string
First Claim
1. A method of determining when tool string parameters should be altered to avoid undesirable effects that would likely occur if the tool string were employed to drill a borehole, comprising:
- modeling portions or an entirety of the tool string in the borehole under steady state loading conditions;
identifying deflections of the tool string with the modeling when the tool string has deformed in bending to a point where the tool string makes contact with walls of the borehole;
determining a bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole;
calculating, based on the bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole, whether fatigue failure of the tool string will likely occur; and
altering at least one of the tool string physical parameters to a level wherein the calculation predicts acceptable fatigue conditions of the tool string.
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Accused Products
Abstract
A method of determining when tool string parameters should be altered to avoid undesirable effects that would likely occur if the tool string were employed to drill a borehole includes, modeling portions or an entirety of the tool string in the borehole under steady state loading conditions, identifying deflections of the tool string with the modeling when buckling would occur for specific tool string parameters, and calculating whether whirl exhibiting similar deflections of the tool string to those identified during buckling would be undesirable.
33 Citations
20 Claims
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1. A method of determining when tool string parameters should be altered to avoid undesirable effects that would likely occur if the tool string were employed to drill a borehole, comprising:
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modeling portions or an entirety of the tool string in the borehole under steady state loading conditions; identifying deflections of the tool string with the modeling when the tool string has deformed in bending to a point where the tool string makes contact with walls of the borehole; determining a bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole; calculating, based on the bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole, whether fatigue failure of the tool string will likely occur; and altering at least one of the tool string physical parameters to a level wherein the calculation predicts acceptable fatigue conditions of the tool string. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of designing a tool string comprising:
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modeling the tool string; applying simulated loads at steady state on the tool string as modeled that create simulated bending to a point where the tool string makes contact with walls of the borehole; determining a bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole; calculating, based on the bending stress caused by the bending to a point where the tool string makes contact with walls of the borehole, whether fatigue failure of the tool string will likely occur; and altering at least one of the tool string physical parameters to a level wherein the calculation predicts acceptable fatigue conditions of the tool string. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification