Ann: Project Icewine Operations Update, page-123

From the DW announcement
"The well was stimulated in two stages over a gross 128 foot vertical interval in the HRZ shale formation, from 10,957-11,085ft TVD, using a slickwater treatment comprising 27,837 barrels of fluid and 1,034,838 pounds of proppant."

From the above article on Slickwater.

"Advantages:

• High retained conductivity, due to no filtercake present.
• Reduced sensitivity to salinity and contaminants in mix-water.
• Reduced number of fluid additives required for slickwater fracturing fluid.

Disadvantages:

• Larger volumes of water often required for fracture design (compared to "gelleg" fracturing fluids).
• Larger horsepower requirement (to maintain high pump rates, 60-110bpm).
• Limited fracture-width (due to low maximum concentration proppant in low viscosity).
• Reduced %-flowback-water recovery (due to imbibement of fracturing fluid in complex fracture network far from wellbore).
• Limitation to fine-mesh propping agents (due to reduced ability of nonviscous fluids in transport of large proppants)."

Might explain some of the delayed flowback and subsequent imbibition.