Aug 21 (Reuters) - Santos Ltd STO.AX :
* Supply gap is expected in medium term" in oil markets
* Demand growth in oil is forecast to remain strong through 2h 2015 and 2016
* Expect $100 million expense in 2h 2015"
* Guidance of 5-18% production growth in 2015"
* Source text for Eikon ID:nASXbFVN5L