In the oil & gas (O&G) industry, non-metallic (NM) composite pipes are gaining traction to mitigate corrosion-related issues that might arise from using carbon steel pipes in severe environment with presence of highly salinity water, carbon dioxide, and hydrogen sulfide. The substitution of the carbon steel pipes to NM composite pipes reduces the number of workover and intervention needed for carbon steel pipes due to corrosion, which indirectly reduces the carbon footprint over the well lifetime. This paper outlines the steps involved in the development, deployment, and operation of the first fully bonded carbon fiber spoolable composite downhole tubular, which reduces the majority of carbon emissions over the tubular lifetime.
This paper highlights key activities, variables and support systems involved in NM composite tubular development and qualification for O&G downhole application. New product development follows general workflow that includes comprehensive understanding on application requirements, environment, load, and challenges. This step is followed by evaluation of feasible pipe designs, construction and material selection, feasibility study on suitable manufacturing process and finally multi-level qualification programs to confirm product specification. Performance envelope derived from qualification tests is utilized to benchmark pipe specification against load scenarios covering the entire pipe lifecycle. Similar approach is also utilized to develop supporting items such as connection and interfaces to other well components. O&G downhole deployment is typically high-risk operations hence, supporting exercises are required to ensure equipment compatibility and operation safety to meet user’s standard practice requirements.
The installation, deployment, and operating environments for various O&G applications- from surface to offshore to downhole fields vary, particularly for load cases in terms of temperature, pressure, and mechanical strength. This results in different material requirement and compatibility in the use environment. As NM composite tubulars are made with different layers and materials typically NM fibers, polymers, and others, material compatibility between layers is crucial during pipe manufacturing. Testing requirements differ too since they have different load cases in different applications, as well as the type of pipe design and construction also demands different qualification needs. This prompts the move to develop a new guideline for qualifying NM composite tubulars in downhole application as existing standards for composite tubulars in other O&G operations are not exactly applicable to downhole conditions, nevertheless, there are interrelated testing concepts between the new guideline and existing standards. NM tubular development process reflects the missing gaps during pipe research and development and eventually allows one to systematically follow the process to develop the first fully bonded carbon fiber composite tubular for downhole application.
Utilizing NM downhole tubulars comprises high complexity, compared to pipes used in other applications. This is the first fully bonded carbon fiber reinforced spoolable composite tubular developed for downhole O&G applications, leveraging newly established holistic protocols. While pipe development poses only about one third of the challenges, the remaining two thirds are associated with the connections and the necessary system components for the different lifecycle phases, making NM downhole tubulars a reality.
