Hello Garyp,

Great Job! This area is/has been studied extensively by Aramco because:

From the Motherlode link:
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Moore[55] reported superficial flood front velocities
v = 15 ft=day over an 8 km span
on the Uthmaniyah flood front.

Saudi Aramco (SA), is attempting to resolve observed, massive, unmitigated hydraulic conductivity between injection and production wells separated often by more than 1 km.

The first fundamental fnding: the predominate, repeated waterflood pattern is that of line drive, specifcally under long and thin, rectangular pattern boundaries. Second: Ghawar water injection wells are often inadvertently hydraulically fractured with unpropped fractures [basically, shooting themselves in their own feet!].

We conclude that these conditions exacerbate the problematic super-k condition, that of early water breakthrough. Our hypothesis for the structure of super-k, containing essential discrete fracture network components, naturally leads to a supposition that the two conditions stated above, are conducive to the formation of highly
conductive pathways, consisting of hydraulic fractures at injection wells, connecting to natural discrete fracture systems, culminating in a network that may significantly
affect production well performance, because it resides in a long, thin bounded region, the tight waterflood pattern.
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I haven't read everything yet, but Aramco mentions horizontal wells watering out instantly, water over-riding oil, loss of drilling mud, and other anomalies due to widespread DFNs.

Bob Shaw in Phx,Az Are Humans Smarter than Yeast?