Study Conducts Mechanical Evaluation of Nonmetallic Tubulars
Authors: Carpenter Chris 
Published: July 2024

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This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 214488, “Mechanical Evaluation and Intervention in Nonmetallic Tubulars Using Current Technologies,” by Mohamed Larbi Zeghlache, SPE, and Khaled Al-Muhammadi, Saudi Aramco, and Iqbal Pervaiz, SPE, Baker Hughes, et al. The paper has not been peer reviewed.

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With increasing interest in nonmetallic products, such as fiberglass tubing, for downhole applications, ensuring well integrity in a similar way as is achieved for standard carbon steel completions is essential. One important aspect of well integrity is the ability to routinely access the downhole condition of the tubing and perform basic interventions. The complete paper demonstrates testing and validation of different mechanical evaluations of the integrity of fiberglass tubing using logging and intervention tools.

Introduction
Fiber-reinforced polymer composites have been used efficiently for various structural applications, including primary structures for which safety is a major design requirement. Fiber-reinforced laminate is very sensitive to out-of-plane loading, however, because it exhibits relatively low transverse properties. The resulting impact damage in fiber-reinforced polymer composite usually reduces its postimpact mechanical properties. The damage phenomenology in fiber-reinforced polymer composites involves many different mechanisms of degradation. Contrary to metallic materials, fiber-reinforced polymer composites can experience damage evolution followed by a catastrophic failure without prior notice. The inspection and monitoring of such damage during a structure’s lifetime are very challenging. Moreover, classical nondestructive testing techniques are difficult to implement for real-time structural health monitoring (SHM). It is, therefore, important to develop a reliable SHM technique that can both increase safety and reduce operational costs by optimizing inspection and repair.

Well-Integrity Evaluation
Of common barrier-inspection technologies, cement evaluation using sonic and ultrasonic measurements is very challenging across coated or nonmetallic casing. In the case of nonmetallic pipes such as fiberglass and composite pipes, this measurement is yet to be investigated for proper transducer design and signal processing. Magnetic and electromagnetic technologies cannot be used for casing inspection because the pipe material is an insulator and prevents any current flow. The simplest and most straightforward technologies remaining are mechanical tools for inner wall inspection. For this reason, testing was conducted to evaluate the effectiveness of multifinger caliper (MFC) logging in fiberglass casing and to simulate intervention operation through puncher and cutter services.

MFC Log in Steel Casing
An MFC is a mechanical tool that provides, through its fingers, high-resolution accurate radial measurements of internal diameter of tubing or casing string. MFCs are used to detect very small changes to the internal surface condition of the tubing or casing with a high degree of accuracy. The tool may be run with extended fingers to increase the measurement range. An MFC tool works in any type of fluid present within the wellbore. MFC detects the scale, wax, or solid buildup on the inner surface of the pipe and any deformation or ovality in the pipe.