American Petroleum Institute

Bulletin on Comparison of Marine Drilling Riser Analyses - First Edition; Formerly Bull 2J
 N BULL 16J

Annotation

Foreword

a. Recognizing the need for a standard method of analyzing marine drilling risers, the API Committee on the Standardization of Offshore Structures began a program of comparing existing computer programs for such analyses. To make this comparison, a standard set of problems was defined and a Task Group formed by the Committee on Standardization of Offshore Structures obtained computer solutions of this set from various participants. The First Edition of API RP 2J was issued in January 1977. This Edition now under the jurisdiction of the Committee on Standardization of Drilling Well Control Systems and renumbered Bul 16J has added a number of deepwater cases along with some random wave cases. The number of participants has increased from nine to 14. The statistical summaries of these solutions are presented in this bulletin.

b. The purposes of issuing these results are: (1) to show the degree of agreement among a representative group of riser analysis computer programs, and (2) to present data which can be used to help validate other such programs.

c. In cases where the results of a participant differed significantly (some 25% or more) from the consistently clustered results of the majority of the participants, results were omitted. Numerous attempts were made by the committee members to assist participants in correcting input errors, problem definitions, and other likely sources of disagreement. The omissions were handled on a problem by problem basis, i.e., the number of solutions used to compile the results for each problem varies. The number of solutions included for each individual problem is indicated throughout the tables and figures in parentheses following the problem designation.

d. None of these results have been directly validated by measurements on equivalent real risers, although some of the programs have been partially validated in other applications. Comparisons such as those described here are not intended to replace or lessen the need for such validation.