In this article the mooring system of an offshore floating anchored structure is reviewed. A criterion and procedure for optimizing the anchor mooring system which ensures the requirements for safe and continuous operation of the structure, taking into account the imposed restrictions is proposed. The optimal mooring system should also provide the widest range of external loads, under which it is possible to continue operating and not transition platform to survival mode. The presented methodology is implemented in a specialized software package that allows determining all categories of external loads, simulate the structure dynamics under the action of loads, and modify the parameters of anchor mooring systems.
Semi-submersible platforms are in active use in the development of oil and gas fields. A necessary part of this process is prospecting and exploratory drilling in various water areas. The purpose of such drilling is a preliminary assessment of deposits types and sizes, as well as their general characteristics.
The design of the structure or its positioning in the water area should be carried out taking into account the requirements of safe operation. Anchor lines analysis is performed to evaluate parameters such as maximum line tensions, angular and linear displacements that can occur under various external conditions. The maximum values of these parameters must be less than the permissible ones to ensure the safety of the structure. The efficiency of the platform over the entire period of operation depends on the time of drilling or extraction. Weather related downtime leads to inevitable economic losses. The operation duration under various external loads is ensured by the competent design of platform mooring systems. The design of the optimal anchor system for operational mode must be carried out for a wide range of external loads. To find the optimal variant it is necessary to analyze which parameters affect the safety of the structure, which parameters can be selected as criteria, and also take into account the constraints imposed on the lines and on the structure (Bolshev, Frolov and Shonina, 2021). The specified parameters will differ for different modes.
