Preliminary Structural Design of an Entire Offshore Oil and Gas Production Complex in Less Than an Hour Using AI-Based Method

Abstract This paper presents a method to carry out preliminary structural design of an entire offshore oil and gas production complex using knowledge-based and AI-aided technique. An overall field layout consisting of multiple jacket-type fixed offshore structures and bridges is generally prepared and optimized by studying various configurations. The computer program developed for the purpose can design each structure/unit of the complex by providing simple input parameters specific to the structure such as water depth, maximum wave height, design seismic coefficient, gross weight of topside facilities, number of conductors, etc. The program generates a detailed analytical model to conduct various structural analyses and material take-off (MTO) for each structure that can be used for estimating the cost. A simulated case of an offshore complex is considered in this paper to study the efficacy of the method. In real cases, the field layout of an offshore complex is selected after considering seismic, geophysical and geotechnical investigation data, guidelines for marine operations, prevalent wind direction(s) and drilling rig approach, as applicable. The selection criteria also include economic viability, capital and operational expenditure, construction methods, availability of marine spread for installation, procurement constraints, priority and sequence of installation of various units, length of the crude/gas pipelines, flexibility to add future facilities, etc. Details of the structures, pipelines, process facilities, utilities and operational requirements are required to estimate the cost of installation and maintenance of each unit of the complex. In this paper, only the structural design is discussed considering that other parameters that influence the offshore field layout design are already investigated before deciding a feasible layout. The numerical study demonstrates the adequacy of each structure by performing the in-place and pushover analyses. By using AI-aided technology the preliminary structural design takes less than an hour without detailed input from the process, mechanical, electrical, utilities and other facilities.