He was speaking to the media after a meeting of the Task Force set up to see to the early completion of the project at Atuabo.
Mr Seth Tepker, Minister of Finance, Mr Fiifi Kwatey, Minister at the Presidency and Mr Charles Darkey, Managing Director of Tullow Ghana, also attended the meeting.
The gas processing plant project, estimated at 750 million dollars, is being undertaken by Sinopec Incorporated.
Mr Buah said work on the project had progressed impressively since the last meeting of the Task Force and “we are sure the project would be completed before the March 31 deadline”.
He said the plant would start operating immediately after its completion because tests would be carried out on the pipes to find out whether there were leaks.
Mr Buah said the plant would start production in June or July this year.
Mr George Sipa Yankey, Chief Executive Officer of the Ghana Gas Company, said equipment for the project that were not already in would be airlifted to meet the completion deadline.