Injectors wells backflow though CTU

[elrufai]

Dear All,
I would like to know more about Injectors wells stimulation through back-flow utilizing N2 lifting with CTU, the calculation and operation procedure, and to how extend it can remove the damage when we have fine movement.
regards
Ahmed

[vinomarky]

Ahmed - sounds like an interesting approach, but not one I have heard of before. My guess would be that it works by back-flowing fines that were present in the injected water and have formed a filter cake in the near-wellbore region. If this is the case, then the approach can't be used to treat traditional fines migration - the analogous procedure would be performing an injection on producing wells to 'back-flow' fines back into the formation, but since the fines are not actually removed, the problem will probably return almost immediately once you recommence production. This phenomenon can be seen during a water compatibility test that consists of pumping a number of pore volumes of water through a core to see how the injectivity declines as function of PV injected, then reversing the direction of the injection at the end to see how much of the lost injectivity is recovered (inferred as due to fines bridging