Drilling Riser Stress Measurements

Field measurements of drilling riser stresses during drilling operations have been made. The field-measured stresses are in agreement with those predicted by EPR’s pseudodynamic riser stress analysis computer program. The agreement between computed and measured values for both time-average stress and stress variations substantiates the validity of the computer program for predicting stress in the upper portion of the riser for the conditions of waves (less than 15 ft in height) and current (less than 1/3 kn) encountered during the data gathering sessions. Stress measurements were made on a drilling riser equipped, with an upper ball joint. It was confirmed that a properly operating upper ball joint is capable of providing a desirable reduction in the stress variation in the upper portions of the riser, thereby mitigating fatigue.