What is the significance of SNE-4, page-6

Great questions Mike,

Follow up question for the geo brains trust: The green blob we call SNE was originally identified based on siesmic studies and other desk geo work. SNE 1 confirmed oil. Now we have 3, soon to be 4 appraisal wells which have extended the green blob SNE and provided the gross and net oil-bearing column dimensions and other stats regarding apparent connectivity, etc. All good. My questions though are:
1. Is their some kind of rule of thumb radius around the well that may be assumed to share the same payload characteristics? Is this effectively the working range of sensors and other gadgets? And in any event, is this radius/limit the basis for 1 and 2c resource upgrades?
2. Does what I am talking about above (assuming it makes any sense at all) relate to Well Spacing in the development stage?
3. And one from left field. Are our appraisal wells reusable at all in a development plan?

(Please don't tell me to use Google. I am already studying this bloody stuff harder than I ever worked at uni.)
Cheers,