DB
That's just an example of static simulation between wells showing the permeability 'highway/corridor' for the fluid.
They dont have actual pulse data yet. Those images show propagation along a set distance. They basically design a grid over an oilfield of say 1 x 1 metre, 10 x 10m, 50x50m, 100m x 100m, 500 x 500m cellsize etc & monitor the rock corridor with decent porosity, permeability, Oil viscosity, Oil saturation, pressure etc.
Basically at SNE, they know:
- the well locations,
- topography or relief of SNE,
- depth where the Sands were intersected in those wells frm the geophysical logs.
- Pressure data frm their MDT tool & DST.
- Porosity, Perm, Oil saturation in the sands
- Velocity/amplitude data from the Sonic, VSP tools & 3Dseis.
- OWC
So they know a lot about what's down there.
Best of all, they know where the oil ends & water leg (OWC) begins to fine-tune their Oil in place calc's.
What's not known with a certain degree of certainity is how that 'Corridor' behaves for the fluid passage between wells A, B & C. That's what their Pressure transient testing will check out.
Think of it simply as chucking a pebble in a pond. U get ripples on the surface & those ripples travel outwards frm the point where the pebble hits the water surface & routes itself around any birds or reeds or trash floating in that pond.
Same thing applies here.
- U create a pulse in 1 well,
- the pressure travels outwards towards other wells,
- They know the distance betwn the 2 wells (eg 3 kms or 6 kms),
- they know the Pressure Injected (eg 2800 psi) & record it at the other wells in PSI (eg 2500 or 2700)
- time it takes for the Pulse reading to arrive at the Observation well (eg 3 hours later).
This testing goes on for some days, as initially they need to filter the signal from tides & overburden effects.
They end up with a graph plotting Pressure versus Time readouts.
One usually leaves downhole gauges in the well which record the Temperature, Pressure every second/min/Hour & transmit the data to a device. The wont need the rig IMO, just a Bourbon will do initially once they r happy with the setup of the gauges & reading readouts on surface for 2-3 days.
That's the simple explanation of it.
Testing will help them eliminate any uncertainities, ie pinchouts in the sand layer or faults that could block the passage. So a lot of 'knowns' and a some 'unknowns' to this puzzle. Hope this helps, kept it simple.
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