Pipe-in-Pipe for Gas Production in Deep Water Offshore Brazil

Abstract

Based on flow assurance studies a Pipe-in-Pipe solution was selected to assure the flow for a gas pipeline connecting the well 4-ESS-138 to FPSO Cidade de Vito´ria located in Canapu field. The flow assurance studies also define the value of 0.8W/m2K for the overall heat transfer coefficient (OHTC) in order to prevent hydrate formation. The temperature of 87°C on the wellhead should be preserved to permit the proper gas flow in 20km PIP length between wellhead and FPSO. Canapu field is located in the offshore area of Brazil (Espirito Santo state) in water depths of 1608m. This paper presents the main aspects related to the detailed design, thermo-mechanical requirements, materials specifications, functional qualification tests performed on materials and on pipe-in-pipe systems to satisfy installation constraints defined by the reel-lay method and operational issues.

Temperature Field Prediction of a Multilayered Composite Pipeline Based on the Particle Filter Method

“…The mathematical formulation governing the heat diffusion problem in the multilayered wall and in the stagnant fluid, represented by eqs. (4)(5)(6)(7)(8), is solved with the finite volume method [21]. The computer code developed for this purpose was verified by using analytical solutions for linear cases, as well as results obtained with other numerical techniques, such as finite differences, for non-linear cases.…”

“…This steady state temperature profile is used to identify the flow rates and the insulation systems that are needed to keep the subsea system above the critical temperature during the production [5][6]. For cases with long tie-backs, pipelines with efficient thermal insulations are required, such as the so-called pipe-in-pipe systems [7,8]. In many cases, the efficiency of the insulation design is also analyzed on the basis of a worst case scenario, such as in a transient event during a production shutdown.…”