Future of Nonmetallic Composite Materials in Downhole Applications

Abstract

This article, written by JPT Technology Editor Judy Feder, contains highlights of paper SPE 198572, “The Future of Nonmetallic Composite Materials in Upstream Applications,” by Wael Badeghaish, SPE, Mohamed Noui-Mehidi, SPE, and Oscar Salazar, Saudi Aramco, prepared for the 2019 SPE Gas and Oil Technology Showcase and Conference, Dubai, 21-23 October. The paper has not been peer reviewed. Nonmetallic (NM) composite-based materials offer distinct advantages in overcoming the effects of corrosion, scale, and friction on carbon steel to minimize frequent workovers and extend the life cycle of critical downhole products. However, high initial cost and technical-skills limitations pose challenges to more-widespread development and deployment of these materials downhole, particularly in extended-reach drilling and other challenging wells. The complete paper highlights examples of nonmetallic materials selection and qualification for upstream water-injection and producer and hydrocarbon wells and presents suggestions for future progress. Introduction Carbon steel (CS) is the material of choice for downhole applications because of its advantages over other materials in terms of cost, temperature and pressure ratings, and field-construction-support services. The downsides of CS include corrosion, scale, and friction that can result in high repair and workover costs and limitations of equipment life. Corrosive fluids are handled generally by chemically inhibited CS and corrosion-resistant alloys (CRAs). However, CRAs can increase project cost and complexity significantly. NM composite materials have been introduced for drilling and completions in high-risk, corrosive environments to minimize the effect of corrosion, scale, and friction in CS tubulars and extend the well life cycle. The new proposed materials are lightweight, high-strength, and offer superior fatigue and corrosion resistance. Economic analysis shows that using NM tubulars and internal linings will yield substantial life-cycle cost savings per well, mainly from the elimination of workover operations. However, composite materials pose several challenges. In downhole environments, the materials are subjected to a more-complex set of dynamic stress conditions under variable multiphase fluids and temperatures. Forces such as burst, collapse, tension, and axial compression play a significant role in NM downhole tubular performance. In deep-well operations, service tools are required to perform at high pressures and temperatures. Currently, the industry has explored the opportunity to deploy NM materials in standard applications while pursuing research and development (R&D) to expand the operating envelope to target high-pressure/high- temperature applications.