An AFE is the itemized estimate of the cost of drilling the well and I usually group it with the proposal to participate because they come together. If you are leased you will not receive one because you can't participate. Usually the AFE is the last resort of an operator, they don't want you to participate and receive 100% less cost of production for your oil. If everyone participated, wells would never be drilled because the operator would only make pocket change and you don't get big expense accounts and operate your company jet on pocket change. The operator wants 80% to 88% net revenue interest, after paying the royalty/mineral owner. If you participated you could earn more per barrel of oil because you would not have to pay anyone a royalty, so if the operator makes $60 per barrel, you could make $80 for each of your barrels. I hope this helps.