Well Remediation Using Expandable Casedhole Liners-Summary of Case Histories
Even with rapidly evolving technology, important issues that continue to challenge the oil and gas industry include conservation of hole size, hydraulic isolation of selected zones, maximization of well life, and economic feasibility. Addressing these issues with conventional tubular technology became more difficult, especially in deep-drilling and extended-reach applications, in wells using liner hangers, and in aging wells containing deteriorating casing. Solid Expandable Tubulars (SET), a revolutionary technology, successfully addresses these issues in commercial applications. The basic piece of equipment that underlies SET technology is a mechanical expansion device known as an expansion cone that is propagated through downhole tubulars using hydraulic pressure. The movement of the cone expands the tubulars to the desired internal and external diameters in a plastic deformation process known as cold drawing. In drilling applications, a specially designed, expandable liner hanger conserves hole size by eliminating the need for a conventional liner hanger/liner hanger packer, and provides a superior pressure seal compared to conventional technology. In cased wells, expandable casing is clad to existing casing to repair or strengthen the existing casing with minimal decrease in wellbore inside diameter (ID) and flow potential. SET solutions have been successfully installed in the Gulf of Mexico, in U.S. inland wells, as well as in large-scale field trials. This paper briefly describes the technical concepts upon which SETs are based and gives an overview of their applications. The paper then focuses on two recent field installations where cased-hole liners were used to help increase well productivity.