The main objective of this project is to demonstrate the potential to economically manufacture microwave-processed coiled tubing with improved performance for extended useful life under hostile coiled tubing drilling conditions.
Pennsylvania State University, University Park, PA
Dennis Tool Company, State College, PA, and Houston, TX
Microwave sintering technology has demonstrated improved quality and cost savings for many ceramics and composite products, especially cemented carbide-based drilling components for the oil and gas industry. In the last 5-6 years, under DOE-funded projects, researchers have successfully developed microwave technology for manufacturing carbide parts. This project is an extension of the researchers’ earlier work. They now are applying their experience to process steel-based coiled tubing. The process involves continuous sintering and bonding of the tubes, both steps to be done in a microwave field. The microwave heating mechanism is fundamentally different from conventional heating processes. In most cases, besides savings in cycle time and energy consumption, the resulting manufactured parts have demonstrated superior performance and enhanced life.
This is a continuation of a project that started in 2002. Phase II of the project has just ended. The experiments conducted through Phase II include processing of several steel compositions and finally selecting 316L as the final composition for prototyping. The steel powder was mixed with wax and cold isostatically pressed (CIP), and then microwave sintered. The bonding experiments to join sintered steel tubes were conducted, and optimum conditions were identified. The samples were characterized for strength, corrosion, bending strength, torsion test, fatigue test and hardness, etc., in the laboratory as well by a third party (Stress Engineering).
If the project goals are accomplished, it is expected that the technology developed could enable the economic production of coiled tubing that offers improved performance for extended useful life under hostile coiled tubing drilling conditions.
During Phase I of the project, the following milestones were accomplished:
Further experimentation and refinement of the sintering process is needed to entice industry investment in commercialization. Improved material characteristics and improved consistency of those characteristics is also needed. The manufacturing of microwave-sintered, industrial quality, full-length tubing is estimated to require several million dollars of investment.
This project was originally funded through a solicitation under NETL’s Gas Technologies Program. The project was forwarded to NETL’s Oil Technologies Program, as it relates to that program’s Microhole Technology Initiative.