Successful Oil and Gas Production Well Applications of Thermoplastic Lined Downhole Tubing: A Compilation of Case Histories Dating Back to 1996

Abstract

Thermoplastic liners are commonly used to protect a wide range of oilfield tubulars offering the advantages of increased corrosion resistance, wear mitigation, and ease of tubular installation while diminishing pressure drop issues and maximizing fluid throughput capacity especially in high rate wells operating with high-velocity fluids. Furthermore, they may offer a competitive advantage over corrosion resistant alloys (CRA’s), plastic coatings and thermoset liner products in extending tubular life. This paper complements a recent paper focusing on water injection and disposal applications of the same liner products. The most commonly used thermoplastic liners in oil and gas production service are largely extruded from polyolefins for installation in environments up to 99°C (210.2° F); yet, for more demanding environments, engineering thermoplastics such as PPS are available to handle temperatures as high as 175°C (300° F). In the most extreme production environments up to 260°C (500° F), liners made of PEEK are utilized. All of these polymers are significantly more flexible and impact resistant compared to traditional thermoset materials historically used to protect injection tubing meaning that they can be practically applied in harsh field conditions and maintain a protective barrier against the tubing ID even after pulling/rerunning tubing combined with multiple wireline and coiled tubing surveys. The same liners can be used to protect costly downhole components and jewelry such as packers and tubing anchors. Examples of lined tubulars with both API and premium tubular connections will be covered. This paper will present case studies detailing the successful use of thermoplastic lined tubulars including liner products composed of HDPE, a proprietary polyolefin blend, PPS and PEEK. All of the lined tubulars in these wells are still in service today and some were installed back in 1996. A review of the critical limitations of the liners such as temperature and diameter changes will also be discussed in an effort to avoid the misapplication of thermoplastic liners. Improved tubular service life, economic benefits, and enhanced flow characteristics due to the high-quality surface finish of the liners will be detailed in at least sixteen specific case histories and production well environments. Furthermore, to exhibit the overall economic impact of thermoplastic lined tubulars, a review of field installation and handling procedures will be presented as well. The fundamental technical benefits of various thermoplastic lined tubulars will be covered with an emphasis on the proven extension of production tubing service life using thermoplastic liners.

Robert H. Davis Polycore, Inc. 1304 Langham Creek Drive, Suite 122 Houston, Texas USA 77084 Fax: 1-281-829-1625 E-mail: robd@wfes.com James G. Hickman Polycore, Inc. 5810 Wilson Road, Suite 250 Humble, Texas USA 77396 E-mail: JimH@polycore.ca