State-of-the-Art on Deep Water Thermal Insulation Systems

Abstract

There are currently a wide variety of insulation systems available for deep water subsea applications. These systems are applied in a number of different configurations including externally bonded systems, pre-manufactured insulation modules that are strapped on to subsea structures and pipe-in-pipe (PIP) insulation systems. The most common insulation materials include polymers such as polyurethane, epoxies and polypropylene and for deep water applications these are used in two main forms; syntactic foam and composite syntactic foam. The limits associated with current insulation systems include lack of experience on the performance of these systems in long-term deepwater service and relatively low temperature limits when exposed to hot/wet conditions. At present, tests for assessing their thermal and physical properties are manufacturer-dependent and, for a purchaser of such systems, need to be interpreted across a range of existing and new materials and manufacturer specifications. The immediate and long-term effects of temperature, hydrostatic pressure and environmental exposure are not yet fully understood. Currently there is a lack of agreed-upon standards for insulation materials. There is a requirement in the industry for the development of consistent standards for the specification, design, materials, manufacturing and testing of insulation materials and systems. To address this requirement a Joint Industry Project (JIP) commenced in April 2000 to develop a new industry wide standard for insulation and buoyancy materials, designated the InSpec JIP. Twenty companies are participating in the JIP, including nine oil companies, eight manufacturers of insulation/buoyancy products and three contractors. This paper presents a review of the current state-of-the-art for thermal insulation systems for deep water applications. The capabilities of alternative systems are reviewed and evaluated. The key issues associated with each system type and critical parameters for the most common insulation materials are presented and discussed. The development of industry standards within the InSpec JIP to address the critical issues for qualification is highlighted within this paper.