DESAIN DAN ANALISIS ABOVE WATER TIE-IN PADA PIPA BAWAH LAUT DI LAUT JAWA

• Main Author: Anindita Rizaldi Putri, Alya
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/40260
• Institution: Institut Teknologi Bandung

The main principle in the process of subsea pipline design is to ensure the pipeline system that is going to be constructed is as safe and robust as possible during the installation process, hydrotest and operation. One of the most important part during the process of subsea pipeline design is to check the installation process since failure on the installation means that the pipe cannot be laid. During the installation process of a subsea pipeline there are different cases in which the pipeline that is being installed needed to be connected with certain parts. Above water tie in, is one of the method that can be used to connect pipeline in which the pipe is welded above the sea surface after the pipeline has been laid. Due to the expensive cost of pipeline repairment or replacement, every process in designing a subsea pipeline has to be carried out through safe and efficient procedure which refers to international design standards. Required wall thickness is designed based on DNV OS-F101 to withstand all kinds of loads during construction, system pressure test and operation. Calculation of the concrete weight coating thickness is based on DNV-RP-E305 which must fulfill the vertical and lateral on-bottom stability analysis criteria. A preliminary installation design is then conducted using a finite element-based software to ensure the pipeline fulfill industrial installation criteria and DNV OS F101 using pipelay vessels with certain specification. The free span analysis is used to obtain the maximum allowable free span length that is later used to predict the pipeline fatigue life. The maximum allowable free span length obtained by using DNV RP-F105 while the pipeline fatigue life can be predicted using software based on DNV RP-F105 and DNV 1981. The above water tie-in analysis uses OrcaFlex software to analyze the pipeline static condition to obtain the davit configuration so that the stress of the pipeline does not exceed the maximum allowable stress.