"I'm wondering if oil drops further if Opec will be able to stop falling the price."

There really needs to be price stability in the energy market. All this volatility and low prices have killed off so many new projects. If you haven't already i would highly recommend reading the new IEA World Energy Outlook paper that just came out. This is effectively the first time that the IEA has looked at the supply side in conjunction with their demand projections.

Anyways, the Oil Drum has a nice ongoing analysis of the report. The actual report is something like 600 pages, so this makes life a lot easier.

TheOilDrum

http://www.theoildrum.com/node/4735