Here is a link I found while doing DYOR.
It is to the Oil & Gas Production handbook.
It makes good reading and can help those who don't know too much about Oil & Gas Exploration / Production.
http://www.itk.ntnu.no/ansatte/Onshus_Tor/Oil%20and%20gas%20production%20handbook%20ed1x3a5%20comp.pdf
Cheers
WizJP