Abstract
The primary objective of hydraulic fracture stimulation is to use “ideal” fracturing fluids to initiate and propagate fractures, transport proppant and place a conductive proppant pack in the created fracture. Resident hydrocarbons may be more easily produced in the created fracture broadway. Thus, optimization of conductive fracture area is perhaps the most critical tenet of fracture stimulation. The effective fracture area is characterized by the conductive fracture height and length, and is often compromised by the inability to place the proppant throughout the created fracture area. Several attempts have been implemented to improve the effective fracture area and fracture conductivity, such as ultralightweight proppant (ULWP) delivery, channel fracturing, and surface modification agent (SMA) coated proppant delivery. The techniques are all based on viscosity-governed proppant transport mechanism.
This paper proposes a new soft particle fracturing fluid system for nearly perfect proppant suspension to improve proppant transport and vertical distribution in fractures. It eliminates the previous limitation to improve effective fracture height by placing proppants across the height of the productive interval under downhole conditions when properly applied. This leads to better transverse and vertical placement of proppant in the fracture and significantly increases the fractured surface area. The degradability of the fluid can lead to non-damaged fracture conductivity with time by internal or external stimulus.
Criteria and considerations in successfully applying such fluids to optimize proppant placement and maximize fracture conductivity are discussed. System design is elaborated in terms of fluid mechanics and proppant transportation mechanics differences and benefits over traditional crosslinked gel system.
