Making Non-Metallic Downhole Tubulars a Reality - Challenges & Way Forward

Abstract

Abstract Non-metallic pipelines are slowly replacing steel tubulars especially in Oil and Gas industry as part of the mitigation strategy to have "corrosion-free" systems, longer life service and lower total cost of ownership. In this paper, authors attempt to provide a discussion of value proposition, technology status quo and future trends, focusing on system challenges on downhole applications, and proposed way forward to build the lacking ecosystem essential to deploy non-metallic tubular downhole. A brief discussion on current technological advancement of non-metallic pipes is supported with market trends towards higher pressure rating and higher temperature resistance pipes to meet stringent downhole well requirements. System challenges, load cases, testing requirement, financial aspect based on well construction and downhole condition are described in depth, focusing on a viable pathway to implement non-metallic tubulars in different wells throughout the lifecycle phases in different applications from water injection to oil and gas production. This study identified the lacking aspects of a fundamental ecosystem needed to confidently deploy non-metallic pipes downhole. By addressing the R&D work necessary for the industry to focus on, efforts can be guided to fill in the missing gaps to build a fundamental ecosystem in order to replace steel tubulars gradually for desired properties. Depending on application requirement, selected non-metallic pipes are designed with various constraints and practical considerations which eventually needs to be tested and qualified for application in demanding well conditions (e.g. wet high temperature and pressure). Other factors than pipe design play as integral component such as connection design and compatibility with existing casing and tubing accessories requires parallel development. Compatibility of connection, end-fittings, and supporting well accessories including drilling tools, completion packers, tubing and casing hangers requires thorough compatibility assurance. Logging tools, etc. are to be either delicately planned out or even require parallel development to accommodate the alternative pathway in place of traditional practices. Detailed study on how non-metallic tubular react to conventional drilling, completion and intervention activities is fundamental to ensure system integrity throughout the well construction process and well lifetime. Emphasis is placed on gap analysis of downhole infrastructure system and associated challenges to utilize non-metallic tubulars and related compatible components in drilling, completion, logging, intervention, and production conditions, as well as the lack of qualification standards for downhole non-metallic tubulars.