State-owned Hindustan Petroleum Corp. Ltd (HPCL) will invest Rs61,000 crore over the next four years in expanding and upgrading its existing refining capacity to meet higher quality fuel norms, the company said in an investor presentation.HPCL is upgrading both its Mumbai and Visakh refineries to produce fuel meeting Euro-VI emission norms.“Major planned investments in refinery, POL (petroleum, oil and lubricants) distribution and natural gas projects,” the company said in the presentation.HPCL will invest Rs20,928 crore in expanding its Visakh refinery in Andhra Pradesh from 8.33 million tonnes per annum to 15 million tonnes by July 2020.