Tuesday, May 28, 2013, Luncheon Meeting Night
Stuart Cox, Marathon
Topic: "A Comprehensive Approach to Tight Oil Decline Curve Analysis"
Register: Registration will be by credit card only, http://spemc052813.eventbrite.com

Decline curve analysis in unconventional reservoirs is challenging due to extremely low reservoir flow capacity, completion techniques and production practices. The primary flow regimes for these wells include bilinear flow, transient linear flow, boundary influenced flow and long term linear flow. Classical decline curve techniques are applicable only during the boundary dominated flow period. Industry attempts to use decline curve analysis over the life of unconventional wells have been performed by imposing limits to the final decline in order to properly constrain estimates of future performance. Long term production performance data from most of these reservoirs is limited. One exception is the Bakken reservoir in North Dakota. Based on historical performance and conceptual studies, it is commonly believed that the dominate flow regime for unconventional developments will be long term linear flow. However, actual performance from recent Bakken and Eagle Ford completions do not always support this belief. Using historical Bakken and Eagle Ford production, this talk will challenge these concepts. Techniques to analyze performance using a flow regime based workflow to guide classic decline curve analysis will be presented. In addition to providing guidance for decline curve analysis, the proposed workflow can also be used to evaluate completion efficiency.

Stuart Cox, Marathon
Stuart Cox is a Senior Technical Consultant with Marathon's Technology organization in Houston, Texas. He has 28 years of experience focused on operations and reservoir engineering. Since 1990 Stuart’s primary focus has been production optimization of low permeability oil and gas reservoirs. He received the SPE Gulf Coast Region Formation Evaluation award in 2012 and was an SPE Distinguished Lecturer 2009-2010. He graduated from the University of Tulsa with a B.S. degree in Petroleum Engineering in 1984 and is a registered professional engineer. Stuart has authored numerous papers published by SPE on performance evaluation of low permeability reservoirs.