Injectivity plot

[AggiePETE]

I have step rate data from a salt water disposal well and I have plotted a graph showing the bottomhole pressure versus the [injection] flow rate which helps me find the formation frac pressure. I want to be able to do use the same plot and add some more graph lines corresponding to lower injectivities. This graph can then be used as a quick reference by the pumpers and operators to see whether the injection well is performing at it's full potential or not. Does anyone have any experience with this kind of issue or might be able to help out?

Your help is much appreciated!

 

[DrillerNic]

It's a pretty standard type plot, mainly used to show if injectivity is changing with time (it almost always does, either increaseing due to thermal fracing or decreasing due to crud in the injection water gumming up the permeability).