This is a late post.
I made a small investment in Sino Oil & Gas (HK:702) on 31 May paying HK$0.52 per share. The company's market cap is relatively small compared to the potential resource value but is speculative given the risks in extracting value from those resources. If they can succeed in bringing the resource to commercial production then there is likely to be considerable upside (at least one broker has a HK$0.78 price target). If they fail, then the loss of value is likely to be significant.
So far it's looking like a bad investment with the shares currently trading at HK$0.48, for an unrealised loss of almost 10% in only a few days.