Estimating fracture pressure (looking for literature to support)

Question

I am trying to estimate fracture pressure of a reservoir when applying injection.

I keep reading fracture pressure=reservoir pressure+2000psi or fracture pressure gradient is 0.7psi/ft, but I can't find anything to support those values.

Can you provide me with a literature or a better way to calculate the fracture pressure?

Answer 1

fracture formula What is the method of injection and fluid you are using? Apply a leak off test to the formation after drilling out casing shoe and your 5-10m into open hole. I’ve attached two links that may be helpful. formation fracture pressure a list of methods There are also plenty of apps for you’re phone that you may find useful. Search “drilling formulas”

Basic frac graduent is 18kpa per meter there fore at 1000m it would take 18000kpa pressure more or less to fracture a zone. In psi it is .8 psi per ft of vertical depth. Usually it takes a higher pressure to frac a formation but feed rates are much lower.

Kind regards Jeff B.