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A review of technology and applications for the in-situ expansion of solid tubulars is presented. The techniques used to accomplish expansion are compared and contrasted with respect to post-expansion performance and suitability for different construction and remediation applications. The evolution of tool designs for both cone and rotary systems and the influence of expansion simulation techniques are discussed. A review of mechanical and environmental performance of steels and corrosion resistant alloys (CRAs) is summarized and the results of recent testing work introduced.
Industry utilization of solid expandable technology has become established in recent years. As of November 2004, the principal expandable service companies have made more than 320 installations. The range of applications has been fairly diverse but can be broadly categorized into well construction or completion/remediation functions.
The impetus for solid expandable tubular development can be traced to early work by operators in the late eighties1,2. The original drive, and still a major aspect in current products and new developments, was to reduce or eliminate the tendency for telescoping in the casing program. The potential primary and secondary cost benefits generated are significant and have been sufficient to initiate long-term research and development programs within operator and service companies. Subsequent opportunities for expandables in different functions, e.g. hanger, isolation, casing repair and sand control devices, were identified and developed concurrently with well construction technologies. In addition to testing and development work on functional and operational aspects of expandable technologies, operators and service companies have been working to determine the effects of expansion on material performance; including both mechanical and corrosion-related aspects. This paper aims to provide an overview of solid expandable technology, applications and testing and to cover some new areas of development.
Abstract For steam injection parameters of greater than 700 psi and 500 deg F, a high production casing failure rate is often observed. This is due to severe thermal stress condition to the production casing string. The production casing may easily be in compression hot-yield under these conditions. This can lead to high casing failure risk in the forms of excessive deformation, buckling, and collapse. This paper presents an analysis on casing and cement stresses under the stated steam injection conditions. The interaction of casing-cement-formation is considered to help understand casing and cement failure mechanisms and potential approaches to reduce casing failures in cyclic steam frac wells. The loss of cement integrity and support to production casing string may occur under steam injection condition, which attributes to casing failures in the forms of excessive deformation, buckling, and collapse. Field surveyed temperature in a cyclic steam frac well is also presented and compared with modeled casing temperatures to show the needs of correctly modeling casing temperatures. Recent casing design practices in some Bakersfield area cyclic steam frac projects, including the successful use of high strength grade casing such as P-110, are discussed in order to reduce casing failures in the cyclic steam frac wells. Introduction In cyclic steam frac wells, high temperature steam (usually above 550 deg. F) is injected into the well though tubing to improve the heavy-oil recovery. For many years, casing failure rate has been high in these type wells. Although it is a commonly accepted casing design practice to assume cement integrity, cement is most likely failed in steam injection wells. Modeling cement stress becomes important to understand its failure risk, and to help improve casing design and reduce casing failures in wells with steam injection.