Abstract

Spoolable pipes are of great interest in O&G industry: they offer well-known advantages like high resistance to internal and external corrosion and low roughness, high fatigue resistance, reduced maintenance cost and improved flow rates. Another important advantage is the easy transportation and installation thanks to the capability of the pipe to be reeled in continuous sections of pipe, which allows reaching high installation rates, also because of their simplified yard: no X-ray, no welding, etc.

In the last five years, breakthrough enhancement in Spoolable pipes performance (materials, manufacturing and quality control) have occurred. The Spoolable market is extremely vital as witnessed by the large number of actual suppliers; however, the different products own significant "different" performances in term of materials and applicability field such as max Pressure and Temperature. For this reason, before the application of these materials in demanding environments (HT, HP, sour service, deep water), a proper assessment is requested.

This paper introduces the Eni installation of two Spoolable reinforced thermoplastic pipes at Zubair Field, South Iraq, and Aquila Field in Italy. The Zubair project started in 2011 when a new type of Reinforced Thermoplastic Pipe (RTP) was developed and available in the market, showing important advantages: the Aramid reinforcement allows a High Density Poly-Ethylene (HDPE) pipe to reach working pressures around 72 bar. Onshore Zubair Field is characterized by high corrosivity of crude oil and injection water, salty soil and need for fast installation. The Spoolable pipes were selected for the water disposal pipelines construction. The installation phase highlights the main criticalities and advantages given by the Spoolable pipe. The second case is the installation of two RTPs at Aquila Field, offshore Adriatic Sea. They are two lines in 850m water depth, used in two sour gas wells. This pipe is made with PEEK polymeric material, reinforced with carbon and glass fibers. The positive results given by this technology allows to consider RTPs also for other applications as oil production flowlines, both onshore and offshore, once the material compatibility with operating limits is verified.

Introduction

Carbon steel is the construction material most widely used for pipelines. However, steel pipelines have a number of limitations, such as low corrosion resistance, relatively high weight and costs.

In the 60s-70s, non-metallics were introduced as pipeline materials to avoid corrosion issue and have been utilized for low pressure onshore gas distribution network.

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