Greenhouse gas emissions from recovery of various North American conventional crudes

• Quantification of emissions associated with recovery of five North American conventional crudes.
• Development of spreadsheet-based models for estimation of GHG (greenhouse gas) emissions.
• GHG emissions from the extraction of California's Kern County heavy oil is the highest among the crude oils considered.
• Use of different sensitivity parameters to check the impact on total emissions.

Emissions from crude recovery contribute significantly to the life cycle GHG (greenhouse gas) emissions of transportation fuels. Recovery emissions come from drilling and land use change, crude extraction, crude oil processing, venting, flaring, and fugitives. In this study an attempt has been made to provide a transparent quantification of GHG emissions from oil well drilling and land use change, crude recovery and associated gas and water treatment, and venting and flaring for five North American conventional crudes through the development of data-intensive engineering models. Estimates of emissions from crude extraction were made from recovery efficiency, the amount of energy used, and process fuel shares in extraction techniques. Extraction emissions vary from 1.24 g-CO2eq/MJ for Bow River heavy oil to 23 g-CO2eq/MJ for California's Kern County heavy oil. The amount of gas vented and flared per m3 of crude extracted was determined to quantify venting and flaring emissions. The amount of energy required for crude oil processing was quantified based on the properties of crude oil and different techniques applied in the oil fields. Of the five crudes we studied, California's Kern County heavy oil and Mars crude oil emit the highest and lowest emissions: 23.85 g-CO2eq/MJ and 3.94 g-CO2eq/MJ, respectively.