Taken from the Jakata Globe (you can tell where I had my holidays), dateline Dec 10, 2008:
State oil and gas producer PT Pertamina will likely miss its December deadline to choose partners to help it develop the Natuna D-Alpha gas block as US oil giant ExxonMobil has yet to turn over key data, an Indonesian government official said on Tuesday.
Edy Hermantoro, director for upstream oil and gas at the Energy Ministry, said ExxonMobil would continue to have control over the block until Jan. 9, when its contract with the Indonesian government officially expires. “Exxon has the right to hold onto the data until its contract is over,” Edy said on Tuesday. “This also means that Pertamina’s right [to take over Natuna] is not effective yet as Exxon’s contract is still valid.”
But Edy’s comments contradicted earlier statements by the Energy Ministry. It announced in 2006 that ExxonMobil’s contract had been terminated, arguing Exxon had produced nothing after 20 years spent exploring the block.
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One of the most tightly guarded treasures of a hydrocarbon production company is its reservoir data. Making this information public domain is kinda like giving your competitors an insight in your 10-15 year revenue and investment plan.
Posted by Wata 
Wata - Malaysian Oil and Gas Engineer 