I don't fully understand the huge interest, but it is the case that a lot of majors and large intermediates are very interested in PNG.
IOC has the most impressive discoveries I've seen but even NGE (ASX) was able to farm out a lot of prospects on good terms.
That one missed its exploration attempts so far but there will be another one later this year. It's pretty undervalued but won't move much until closer to the spud date or on news of another farm out. I have my fingers crossed that they will eventually hit something significant.
Mitsubishi/TLM/XOM etc. are all investing in the PNG.