Resource Assessment

The association of geological description to production performance is the key in providing a successful development program and to capture the highest value from any subsurface asset. Although there are several proven technologies that can be deployed for this task in conventional onshore and offshore fields, that task becomes very difficult to accomplish in unconventional plays. Having the benefit of shale engineering and modular design, one has to adopt and scale these concepts on the development level, which may encompass hundreds of square miles.

Although the concept of “sweet spots” has been addressed many times, one needs to process huge subsurface datasets, filter the variables that are relevant in terms of playing a major role in future performance to provide a clear map of subsurface prioritization. Similar to the subsurface, surface prioritization follows a similar process addressing land and facility concerns. The combination of those two gives a map of prioritization that development needs to follow. That work is necessary in order to plan better towards company profitability in the face of volatile market conditions. The density of contributing data in these maps can be used to derive relative risk factors and to direct future operations accordingly. The accuracy of those maps can be checked through controlled sampling and when the overall maps attain a certain level of confidence, they can provide a basis for an objective and principles based reserve and resource assessment.

In certain cases natural fracture networks and well interference may result to a more complex and convoluted “sweet spot” which may be dynamic in nature as old operations may impact future development as the natural fracture network gets pressure depleted and saturated with separated water or gas at the lowest and highest areas according to their distinctive densities.

George Vassilellis and Emad Elrafie. 2016. “Geologic and Dynamic Indicators Offering a Reliable Technology Paradigm to Reserve and Resource Estimation in Unconventional Oil Plays” SPE 179952-MS, SPE/IAEE Hydrocarbon Economics and Evaluation Symposium, Houston, Texas, USA, 17–18 May 2016.

Emad A. Elrafie, and George Vassilellis. “Tight Oil Unconventionals: Better Reservoir and Performance Understanding Resulting in a Novel Development Ranking Methodology Achieving Higher Recovery Through Dynamic Sweet-Spots Modeling”. 2016. AAPG 2383060, Annual Convention and Exhibition, Calgary, Alberta, Canada, June 19-22, 2016