Stress Distribution Analysis of DKDT Tubular Joint in a Minimum Offshore Structure

Abstract

A marginal field defines as an oil and/or gas field that has a short production period, low proven reservoir, and could not be exploited using existing technology. As the demand for oil and gas keeps increasing, one of the solutions to tackle the issues is to build the modified platform which came to be more minimalist to conduct the oil and gas production in the marginal field. Naturally, the minimum offshore structures are cost less but low in redundancy, therefore, pose more risks. Although the study on the minimum structures is still uncommon, there are opportunities to find innovative systems that need to have a further analysis toward such invention. Therefore, this study took the modified jacket platform as a minimum structure, and local stresses analysis by using finite element method is applied for the most critical tubular joint with multiplanarity of the joint is taking into account. The analysis was carried out using the finite element program of Salome Meca with three-dimensional solid elements are used to model the multiplanar joint. Various loading types of axial force, in-plane bending moment, and out-of-plane bending moment are applied respectively to investigate the stress distribution along the brace-chord intersection line of the tubular joint. The results show that the hotspot stress occurred at a different point along each brace-chord intersection line for each loading type. Finally, as compared to the in-plane bending moment or out-of-plane bending moment loading types, the axial force loading state is thought to generate greater hotspot stress.

Stress Concentration Factor Estimation of a Multi-planar DKT Tubular Joint through Finite Element and Machine Learning Approaches

“…Data needed for this study, namely platform data, geometry data and material properties of the DKT tubular joints, are based on [9]. The platform and the DKT connection are shown in Fig.…”

The Effect of geometric parameters on stress concentration factor of a multiplanar DKT tubular joint through finite element model

“…Then, the result from the global analysis is extracted, namely platform data, geometry data, and material properties of double KT tubular joints. The global analysis data used from the previous study by Noviyanti [2,12] with the detail DKT connection shown in Figure 3 and…”

“…Thus, the stress distribution studied in uni-planar connections is not accurate in determining the stress distribution in multi-planar connections which is present in the majority of jacket structure joints. Then, some studies show that the variation of geometric parameters have influences to hotspot stress, which later influence the SCF [2,3]. The amount of SCF depends on the geometry of the joint, the type of loading, the size, and the type of weld [4].…”

Bending load effects on stress concentration factor distribution of multi-planar DTKY tubular joints

“…However, the proposed SCF formula for two planar joints is still limited. Stress distribution along the weld toe for the DKT joints was analyzed by Noviyanti [12] and continues for SCF estimation for two planar DKT joints [13]. Other joint type, such as multiplanar DTY type was also studied [14].…”