Hydraulic fracturing in multi stage horizontal unconventional wells is perhaps one of the most important if not the most important in the drilling and completion cycle of these wells. It's also the most applied technique repeatedly in multiple formations throughout the world and yet the question that looms large over us, do we understand the fracture geometry in these unconventional environments. Year on year most unconventional formations seem to fall in line with the industry trend of increasing lateral lengths and pumping more stages to improve production and recovery. Again, we need to ask ourselves if this is sustainable. Introspection of data available from public data seems to indicate that a significant chunk of these wells buck the trend of increased lateral lengths and stages and we still continue to apply these techniques especially in a price sensitive oil market. What if we could challenge this paradigm through a systematic engineering process that could relate the impact of fracture geometry and well spacing? We selected one of the up and coming plays in Canada that is on the road to development called the Duvernay.
The Duvernay Formation is a unit of the Woodbend Group and is considered as the source rock for prolific reservoirs such as the Leduc reefs. Duvernay formation holds an estimated 443 trillion cubic feet of gas and 61.7 billion barrels of oil.
This paper is an attempt to model and understand complex hydraulic fractures in a multi well pad environment coupled with production modelling to understand drainage patterns. Public data from the IHS database was used to construct and build a geocellular model and wells that had petrophysical and geomechanical data were used to build a representative well pad model. Using the model built complex fractures using the unconventional fracture models were simulated in a multi well pad environment. Impact on reservoir drainage has been assessed with various simulations by changing different parameters with respect to hydraulic fracturing. The results of these various simulations are presented in the paper and these simulations act as a tool to understand when possible interference may occur in these pads. Spacing of wells and frac sizes can be adjusted to minimize competitive drainage between wells.