We do have possiblities of petroleum reservoirs beneath the soft sediments of Terai Plain. If we had not any possibilites of petroleum prospects, big exploration houses wouldn't have applied for the exploration. But the main barrier for the exploration work of petroleum prospects  in Nepal is political instability of the country because everyone seeks security of huge investment that will be required for the exploration work.

If anyone has more interests to know about the geological evalutaion on the petroleum prospects of Nepal please follow this link.

http://www.cseg.ca/publications/journal/1994_12/1994_04_petro_geo_nepal.pdf