Eindhoven University of Technology, Netherlands
Title: Selective propping of high conductivity fractures
David Dogon is from Eindhoven University of Technology, Netherlands.
Controlling fluid transport in the subsurface is important for secondary oil recovery, geothermal heat mining and proppant placement in fractured reservoirs. Limiting fluid loss through fractures in the formation is important for preventing bypassing of oil rich zones. For unconventional gas, larger fractures need to be selectively propped. The process of orthokinetic agglomeration, whereby particles are aggregated by means of fluid shear, has the potential to selectively narrow or block large fractures. This is achieved by coupling the fracture wall shear rate to the fracture size, where higher shear rates in larger fractures result in higher rates of orthokinetic agglomeration. It was estimated the differences in shear rate between fracture sizes and perform laboratory investigations on shear-induced particle growth using commercial well mud particulates. Particle growth rates peak at a shear rate of 275 s-1. This maximum shows that it is possible to selectively grow particles based on shear. It was also shown that the availability of precipitating ions act as “glue” maintaining newly formed agglomerates, suggesting the importance of solution chemistry in the process.