Ann: Operations Update, page-260

My understanding, as per LSE as well;


Read this and do the science......if you can

''Ideally U perforate a lower interval, then set a bridge plug & then perforate an Upper zone. Which is that they've done.

Bridge plug ensures that each zone is isolated. One knows the volume of frac juice pumped per zone (either in 1 hit or in stages) & eventually recovered during flow-back. On the surface one monitor's the Pressure. That's where they seem to have realised at IW#2 that the 2 intervals are connected. (From the two well data, W1 and W2)

In my view, this could possibly b due to the brittle nature of the matrix (highly siliceous, less clayey) & geomechanics. So when they fracc'd it, combination of insitu stress conditions & any localised 'features' ie cracks or joint planes etc got extended & connected.

On the Image logs (pre-fracing) these features show up as dark & light bands representing either bedding planes in the Shale, any local cracks/joints/shear planes/faults etc &/or change in well bore dia. Anyways that's where Rock mechanics is critical. Sonic logs r run to identify zones where there's any change in velocity of waves that propagate thro' the rocks/fluids & tells u about the Poisson's ratio, Young's modulus etc. It's too technical info to discuss on a chat forum.''