A Workability Analysis of Semi-submersible Rig for Operation

Abstract

Semi-submersible rigs are more versatile than ship shaped drilling rigs for operations in deep water areas due to its better ship motion characteristics.
Presently, a number of semi-submersible rigs used as the production platforms for small-sized oil fields are increasing.
However floating rigs including semi-submersible sometime have difficulties in coping with environmental factors such as deeper working water depth and harsh meteorological condition.
Workability of semi-submersible rigs utilized in the areas can be calculated based on operating limited value of the rig behavior constructed elements which consist of riser, mooring and hull. An optimum system as well as operational safety can be determined by maximizing the workability in the field.
This paper shows the outlines of; (1)analysis of consisting elements, (2)spectral analysis method, (3)calculating method of workability with irregular response.
The computer analysis is used to accurately calculate workability of the semi-submersible rig operation in relation to environmental condition in the field.
As the results of above methods and analysis, the optimum system of the semi-submersible rig for the preselected field can be determined.