Deepwater Steel Catenary Riser System Design for Lingshui 17-2 Project

Abstract

A riser is a key component for transporting produced oil and gas from the subsea wells to the surface production vessel. Through nearly 30 years of design and implementation, Steel Catenary Risers (SCRs) have been found to have the advantages of relatively low cost and good adaptability to floating platform’s motion. This paper investigates deepwater SCR system design for the Lingshui 17-2 (termed LS17-2) project. This paper first introduces a SCR system for the LS17-2 project. The field for this project is located in the northern South China Sea, with water depth of 1220m to 1560m. LS17-2 consists of a subsea production system, a deep-draft semi-submersible (SEMI), and an export riser/pipeline. The platform was designed to have a large storage capacity with a variable draft during its operation. Based on deepwater SCR engineering experience, the key SCR design challenges are summarized from the engineering executive perspective. The challenges to the SCR system design for the LS17-2 project include harsh environment condition in South China Sea and the impact on fatigue design for the requirement of 30-years’ service life. They call for design optimization and innovative ideas. The engineering design and analysis are discussed together solutions. To demonstrate the deepwater SCR system design for LS17-2 project, examples are provided to illustrate the challenges and solutions. The experience learned from this paper should have significant relevance to future SCR design.