Mechanics of Heat Loss in Dry Tree Top-Tensioned Risers

摘要

Application of dry tree top-tensioned riser systems provides direct vertical access to reservoir via production risers and surface trees, wellbore access for artificial lift and wireline and coiled tubing. While the dry tree riser is gaining growingly attention for deepwater development, the challenge has raised for flow assurance engineering, mainly for the thermal analysis of the dry tree riser - a complex heat transfer system. This paper focuses on the mechanisms of heat transfer in dual and single casing dry tree riser systems. The dry tree riser is a complex system and the heat transfer through the multiple wall of dry tree riser is a complicated process. Current understanding of such heat transfer mechanism is far from satisfactory, often resulting in a large deviation between the predicted and actual system thermal behavior, and temperature profiles or trends. To compensate this, the industry often applies a large safety factor for the system design. This paper reviews dry tree riser related heat transfer study and research in the industries and academics analysis, and provides the state-of-the-art of heat transfer analysis methods for dry tree riser to offshore system engineering and flow assurance, to improve predictions of riser thermal performance at system design phase and for steady state and transient production operation.