Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Development of Carbon Nanotube Composite Cables for Ultra Deep Water Oil and Gas Fields
Los Alamos National Laboratory
Chevron Energy Technology Company
The purpose of this project is to develop a new technology for electrical power cables, using a composite of carbon nanotubes (CNT) and copper. The primary goal is to build a CNT-copper composite cable with twice the conductivity of an equivalent size pure copper cable. This composite cable should also be lighter and stronger than a comparable copper cable. The higher conductivity of this new power cable will allow more electrical power to be delivered downhole in wells to power more boost (pumping) capacity and greater well productivity. The new cable would transmit electrical power more efficiently, with less loss than a copper cable. The new cable could facilitate moving more processing components to the seafloor from surface facilities. It could also help enable extending tiebacks to longer distances while carrying as much or more electrical power along the tiebacks. With its increased ability to carry power where it is most needed, the technology could help lower the cost of developing deepwater oil/gas resources.
Description of project:
This project will carry out materials research and development needed to develop a new type of electrical cable using a composite of carbon nanotubes (CNT) and copper. Carbon nanotubes are small diameter (about 20 nm) tubes, up to a few mm long, with carbon atoms in a highly structured arrangement. The electrical conductivity of individual nanotubes can be 1,000 times greater than copper. In addition, they are lighter and stronger than copper. The purpose of combining carbon nanotubes with copper is to build a composite CNT-copper conductor with double the conductivity of a pure copper cable. The prototype composite cable should also be lighter and stronger than a pure copper cable.
Although carbon nanotubes have high conductivity individually, the conductivity from one nanotube to another is low. The key technical problem for the project is to find a way to create high electrical conductivity between individual carbon nanotubes. The project will test several approaches for doing that, and use the best approach to fabricate a prototype composite cable.
The final deliverable by the project will be a 100 m long carbon nanotube copper composite cable with twice the conductivity of a comparable size copper cable. Intermediate deliverables are shorter prototype cables with successively higher conductivity, starting from a 2 m long cable with about 13% greater conductivity than copper, which is the deliverable after the first six months of the project.
The new composite cable technology will be able to carry much more electrical power into wells to power increased downhole boost (pumping) and increase the production from wells. With this increased efficiency, smaller fields in the ultra-deepwater can become economic to develop. The new cable technology should also reduce the costs of carrying electrical power down to the seafloor from generating facilities on the surface. The new cable technology may also allow power delivery over greater subsea distances, enabling efficient transmission with longer tieback distances.
Chevron Energy Technology Company is a cost-share participant in this project. Chevron will provide cash funding to Los Alamos at a level of 20% of the project budget. They will also provide in-kind contributions in the form of technical interactions with Los Alamos and guidance during the project.
Principal Investigator: Dr. Kenneth Marken
Phase 1 Final Report [PDF-492KB]