Numerical Feasibility Study of Electric Heating Strategies for Subsea Tie-In Flowlines Using a 1-D Mechanistic Multiphase Flow Simulator

Abstract

This paper reports the outcome of a study investigating four electrical heat-tracing strategies that can be employed to avoid wax deposition in subsea flowlines transporting untreated crude oil from subsea wells to a host installation. The strategies, described in the paper, are distinct by the configuration of deploying the heat tracing along the pipe and by the activation schedule (continuous or alternating heating cycles). The study demonstrates quantitatively that the electrical power required for maintaining wax-free flow depends strongly on the employed strategy. The complex thermo-hydraulic flow was modeled using a commercial Dynamic Multiphase Flow Simulator with wax deposition option and thermal insulation as an input parameter. In conclusion, the paper ranks the strategies according to their computed energy efficiency, thus providing quantitative benchmarks for preliminary wax control assessment.

Thermal system for a new flexible composite tank

“…At present, the heating and insulation efficiency of pipelines can reach 90% through use of combined Frontiers in Materials frontiersin.org applications (Angays, 2011). A combination of heating and insulation has been recognized as the most efficient method, and studies have focused on multiple layers of insulation (An and Su, 2015;Parsazadeh and Duan, 2015), the influence of different heating efficiency on heating effects (González et al, 2018), and the application of other methods, such as electrically trace heated pipe-in-pipe (Jez et al, 2020) and eddy current manufacturers (Park et al, 2015). However, most of the studies remain at the stage of theory and numerical simulation and lack relevant model testing.…”