The company's SIA vessel installed 44 cables at the project site, located 37 kilometres off the German coast.
CT Offshore was handed the contract by Dong in February. It operated out of Nordenham, Borkum and Eemshaven harbours.
The company will now start preparing to install cables at the Gode Wind 1 and 2 projects, also developed by Dong.
Turbine installation at Borkum Riffgrund 1 began in October but was delayed "by a few weeks" due to manufacturing problems for supplier Siemens.
However, Siemens and Dong said the commissioning date for the first half of 2015 would not be affected. Siemens is supplying 77 4MW turbines to the project.