Recently, the flow of fluids into a fracture from a point source has been the subject of several different papers. Cleary and Fonseca1  first suggested that convective transport should play a major role in the placement of proppant when the flow into a fracture was from a point source. Clark and Courington2  presented data showing that for non-viscosified fluids convection was the dominant mechanism of transport. However, they showed, that for uniform fractures, viscosifying the fluid made a large difference in the transport mechanism. In a later paper, Clark and Zhu3  presented data for non-uniform fractures and viscosified fluids weighted with either salt or silica flour that showed that the presence of minor non-uniformities serve to negate the effect of convection even more than viscosifying the fluids.

In this work, we have extended the work presented in the previous two papers to high viscosity Newtonian fluids and crosslinked fluids. The experiments have all been done with various concentrations of silica flour to simulate added proppant. Both changing the nature of the non-uniformities and crosslinking the polymer solution have a profound affect on the flow into the fracture and the convective process.

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