Oil industry CO2 per barrel?

We have constructed a simple model to estimate full-cycle CO2 emissions of an oil resource, as a function of its flaring, methane leakage, gravity, sulphur content, production processes and transportation to market. A c10x energy return on energy investment is estimated. Relative advantages are seen for well-managed resources offshore and in shale; relative disadvantages are seen for heavy crudes, as well as poorly managed gas.