Increasing the Application Realm of Solid Expandable Technology

Technology that boasts versatility is indicative of true innovation. Take for example solid expandable tubulars. Since 1999, upstream operators have successfully used solid expandable tubulars with over 900 installations worldwide. The success of these tubular systems to mitigate wellbore challenges and casing problems has prompted pipeline operators to consider the transfer of solid expandable technology to pipeline repairs and restorations. A key value proposition that initiated the pipeline industry’s attraction consists of the technology’s permanent, steel, pipe-in-pipe ability to improve structurally at-risk or derated pipelines with only minimal ID loss. Although local distribution companies have used liner technology extensively in settings where lines operate at much lower pressure than most transmission lines, the use of steel lining is new. The concept is simple: insert a smaller pipe inside a larger pipe and, using pressure, drive a specially designed mandrel through the smaller pipe to accomplish a controlled expansion to fill the annular space between the two. This less-intrusive process is a “trenchless” solution to replace and repair sections thinned by corrosion to maintain maximum throughput and reinforce pipelines against external loads to prevent buckling or collapse from soil movement and shifting formations. Such an approach enables pipeline restoration with minimum disruptions due to repairs—a significant benefit in heavily congested areas and geologically sensitive environments. Research indicates that prime candidate applications of solid expandable technology exist in situations where traditional excavate-and-repair techniques are difficult to use, cost prohibitive, or would disrupt public movement. In such settings, the two broad categories solid expandable technology would address most effectively are capacity restoration and anomaly repair. This paper will discuss conventional solid expandable tubular technology and the legacy it provided to transition to pipeline applications. Expansion value and application will be discussed in addition to lab and surface testing and development-to-date. In addition, this paper will propose the next steps needed to transition the technology to a viable pipeline rehabilitation method.