CALGARY, Alberta, May 11 (Reuters) - Husky Energy Inc (HSE.TO: Quote, Profile, Research) said on Monday that a second follow-up well to its Liwan natural gas discovery in the South China Sea could produce at a prolific 150 million cubic feet a day.

Husky said the appraisal well on the play, which it is developing with China state oil company CNOOC Ltd (0883.HK: Quote, Profile, Research), tested at 55 million cubic feet a day, a rate that was restricted by the equipment.

Indications are "that future well deliverability could exceed 150 mmcf per day," the Canadian-based oil producer and refiner said in a statement.

The well, called Liwan 3-1, was drilled to a total depth of 3,668 metres (12,030 feet) below sea level.

Husky has estimated reserves at the Liwan discovery at 4 trillion to 6 trillion cubic feet. The company is looking at designs for developing the field, with production targeted for 2012 or 2013.

Last month, Husky said it planned to spin off its Asian assets, including Liwan, into a new company that would be listed on a stock exchange in that region as a way to boost value for its shareholders.

The deepwater rig that drilled Liwan 3-1 is now preparing to drill a second exploration well on the block, Husky said.

Shares in the company, which is controlled by Hong Kong billionaire Li Ka-shing, closed down C$1.40 at C$32.23 on the Toronto Stock Exchange. Husky released the drilling results after the market closed.

($1=$1.17 Canadian) (Reporting by Jeffrey Jones; editing by Rob Wilson)