CNT-Filled Polymer Feedstocks for Material-Extrusion Additive Manufacturing in Oil and Gas Applications

Carbon-nanotube (CNT)-filled thermoplastic filaments can combine the geometric freedom of fused filament fabrication (FFF, also termed fused deposition modeling) with electrical, sensing, electromagnetic-shielding, or selected mechanical functions. This critical review evaluates these materials' potential separately from the performance and qualification of printed components for oil-and-gas service. The literature considered includes CNT/polymer feedstock and printed-part studies, relevant work on FFF interlayer structure and test methodology, and reviews of additive manufacturing in energy-sector applications. It is treated as a narrative review rather than a systematic search. Across ABS, PLA, TPU, PBT and PEEK matrices, experimental studies demonstrate printable CNT-containing materials and application-specific functions, but reported outcomes depend on polymer, nanotube type and loading, compounding route, filament quality, print parameters and build direction. Conductivity and sensing are particularly sensitive to network structure and measurement direction; the presence of CNTs does not ensure large thermal-conductivity gains or improved strength in every system. The available evidence does not establish qualification of CNT/FFF components for mission-critical oilfield service. In particular, application-representative chemical exposure, pressure–temperature aging, creep, fatigue, network stability, manufacturing repeatability and traceability must be linked to component-level acceptance criteria. A staged validation pathway is proposed, with standards used as test scaffolds rather than proof of service suitability. The central conclusion is that CNT/FFF materials have demonstrated laboratory functionality, while field readiness remains an unproven engineering claim.