High temperature insulated pipelines

Abstract

An insulated high-temperature transport conduit for use in undersea environments. The conduit comprises a continuous steel pipe having at least a first layer of thermal insulation provided over its outer surface. The first layer of thermal insulation comprises a polymer composition having a thermal conductivity of less than about 0.40 W / mK and long-term heat resistance at continuous operating temperatures within the range from about 150° C. to above about 205° C. The first thermal insulation layer comprises a polymer composition comprising a polymer selected from the group consisting of one or more fluoropolymers, hydrogenated nitrile butadiene rubber (HNBR), and a blend of one or more fluoropolymers with HNBR. The conduit may further comprise second and third layers of insulation on top of the first layer, along with a corrosion protection coating underlying the first thermal insulation layer.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and the benefit of U.S. Provisional Patent Application No. 61 / 863,976 filed Aug. 9, 2013; and U.S. Provisional Patent Application No. 62 / 021,751 filed Jul. 8, 2014.FIELD OF THE INVENTION[0002]The present invention relates to insulated fluid and / or gas transport conduits, and methods for the production and application thereof. More particularly, the insulated transport conduits comprise undersea pipelines for carrying single or multi-phase fluids such as oil, gas and water, particularly such pipelines operating at temperatures from about 150° C. to above about 205° C.BACKGROUND OF THE INVENTION[0003]There is increasing demand in the oil and gas industry for higher performance thermal coatings to insulate and protect off-shore transport conduits operating at temperatures from about 150° C. to above about 205° C. In order to maintain the conduit at the required operating temperatures in an undersea environ...

AI Technical Summary

Benefits of technology

The patent describes an insulated high-temperature transport conduit for use in undersea environments. The conduit is made up of a continuous steel pipe with a layer of thermal insulation made of a polymer composition. The polymer composition has a low thermal conductivity and long-term heat resistance at continuous operating temperatures within a range of 150°C to 205°C. The thermal insulation layer is made of a polymer composition comprising a fluoroelastomer, such as HNBR or nitrile butadiene rubber, and a crosslinking agent. The polymer composition may also include a foam, such as a syntactic foam. The conduit may also have a corrosion protection coating and an outer protective topcoat. The patent also describes the use of different thermal insulation layers, including a second layer made of solid or foam polypropylene homopolymer or copolymer, polybutylene, polyethylene, or a combination of these materials. The second thermal insulation layer may also comprise an epoxy-modified polymer network or an elastomer. Overall, the patent provides a technical solution for insulating high-temperature transport conduits in undersea environments.

Problems solved by technology

Both of these phenomena are related to the temperature of the fluid, and in extreme cases the conduit can become severely constricted or even blocked.

This in turn can lead to reduced or lost production.

In particularly serious cases this may lead to the need to replace sections of pipeline or entire systems with corresponding loss of asset value.

Hence, the traditional thermal insulation foam technology used in shallow waters and the associated design and test methodologies may not be applicable to deep-water projects, where the depths may exceed about 1,000 meters.

In cases of long pipe tiebacks, for example subsea-to-beach tiebacks, and in cases where the service temperature is above approximately 150° C., there exist limitations with current technology that may hinder the successful development of offshore, deep water oil or gas fields.

Limitations and deficiencies of these technologies include:Relatively high thermal conductivity of known insulating systems, necessitating excessively thick coatings to achieve the required insulation performance, leading to potential difficulties in foam processing, potential issues with residual stress, difficulties during pipe deployment, and sea-bed instability.Insufficient resistance to temperatures from about 150° C. to above about 205° C., resulting in compression and creep resistance issues in high temperature installations at high water depths and material degradation resulting in a loss of mechanical properties.Excessive costs due to poor material cost versus performance capabilities or high transportation and deployment costs.Deployment and operation disadvantages with Pipe-In-Pipe systems due to weight factors leading to buckling and weld failure if not properly addressed, and the need for high gripping loads during pipe laying.

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