Abstract: A method of heterogeneous proppant placement in a subterranean fracture is disclosed. The method comprises injecting well treatment fluid including proppant and a channelant through a wellbore into the fracture, heterogeneously placing the proppant in the fracture in a plurality of proppant clusters or islands spaced apart by the channelant, and removing the channelant filler material to form open channels around the pillars for fluid flow from the formation through the fracture toward the wellbore. The proppant and channelant can be segregated within the well treatment fluid, or segregated during placement in the fracture. The channelant can be dissolvable particles, initially acting as a filler material during placement of the proppant, and later dissolving to leave the flow channels between the proppant pillars. The well treatment fluid can include fibers to provide reinforcement and consolidation of the proppant and/or to inhibit settling of the proppant in the treatment fluid.

Abstract: An embodiment of a downhole method of breaking of a well treatment fluid relates to overcrosslinking a polymeric thickener with an overcrosslinking agent such as an excess crosslinking agent and/or an excess alkaline material, wherein either or both the agent and/or material may be encapsulated.

Abstract: A method of stimulating production from a subterranean formation penetrated by a wellbore, comprising pumping a fluid from the well into the formation so as to create a hydraulic fracture. The fluid contains one or more reactive species that destabilize cohesive forces in the formation matrix. The method allows the fluid to leak of into the formation and react with the formation matrix so as to produce a destabilized zone in the formation around the location of the fracture such the formation fluids and sand particles can be produced from the formation through the zone and into the well.