Standards Development

Scope

This document specifies technical requirements for thermoplastics lined tubing used in the petroleum and natural gas industries, including configuration and materials, manufacturing, inspection and testing, marking, packaging, transportation, and storage.

The thermoplastic lined tubing is suitable for extracting multiphase fluid, hydrocarbon liquid, gases, and water under corrosive, abrasive, wax dipositive, and scaling environments.

Thermoplastics in this document considered includes, but is not limited to, high-density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), polyphenylene sulfide (PPS) and polyetheretherketone (PEEK), which satisfies the appropriate design codes, standards or regulations.

Purpose

Oilfield pipelines - both for water injection and oil transmission – experience corrosive conditions because of the presence of CO2, H2S, O2, and various ions and bacterial agents. In addition, complex scaling processes give rise to various types of scale that are difficult to prevent and remove. Nonmetallic materials such as composite, ceramic and thermoplastics are perfect selections to improve the corrosion, abrasion and scaling resistance of the steel tubing, if there are lined in the tubing. Till now, API RP 15CLT gives Recommended Practice for composite lined steel tubular goods, and ISO/ PAS 24565 provides the requirements on ceramic lined tubing. For thermoplastics lined tubing, only API Spec 15LT: 1993 covered the polyvinyl chloride (PVC) lined tubing, but it was withdrawn now. Actually, different thermoplastics such as high-density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), polyphenylene sulfide (PPS) and polyetheretherketone (PEEK), had been widely used as the liner on the inner wall of the tubing due to their good abrasion resistance, excellent scaling and corrosion resistance, high mechanical properties, etc. Hence, thermoplastics lined tubing has a great developing prospect.

However, the investigations indicate that there is no corresponding international standard specifying the manufacture, inspection, quality control, purchase of thermoplastics lined tubing in petroleum and natural gas industries, which causes many inconveniences for this composite pipe. For example: 

 1) It is inconvenient for the international trade of product;

2) It is difficult for the manufacturer to provide requirements for selecting and treating the tubing when developing thermoplastics lined tubing;

3) It is not conducive for pipe manufacturers putting forward technical requirements to determine application scale of this product;

4) It operates to the disadvantage of pipeline construction companies to evaluate the quality and choose the right product for the project, etc. 

Therefore, it is very necessary to set up an international standard about thermoplastics lined tubing in petroleum and natural gas industries. In the last more than ten years, lots of research in the field of fabrication process, properties, joining, quality evaluation and other aspects of thermoplastics lined tubing have been systematically conducted. A relative complete fabrication, joining, quality control and purchase system have been established. The key technical parameters of the product have also been confirmed. The research results have been successfully used in the pipeline construction and play an important role in ensuring the safety and reliability of pipelines.

This standard can be used as guidance to manufacture, inspection, quality control, acceptance and purchase etc. of thermoplastics lined tubing in petroleum and natural gas industries.