Settable, form-filling loss circulation control compositions comprising in situ foamed calcium aluminate cement systems and methods of using them
This document relates to settable, hydraulic, non-Portland foamed cement compositions comprising nitrogen gas-generating compositions used for loss circulation control.
1. A method of treating a loss circulation zone in a subterranean formation, the method comprising:
a) forming a foamed cementitious composition comprising:
calcium aluminate;
a nitrogen gas-generating compound;
an amine activator comprising an ethyleneamine; and
a foam surfactant; and
b) introducing the foamed cementitious composition into the loss circulation zone.
2. The method of claim 1 , wherein the nitrogen gas-generating compound is an azo compound.
3. The method of claim 2 , wherein the azo compound is about 1% to about 10% by weight of the calcium aluminate.
4. The method of claim 1 , wherein the ethyleneamine comprises tetraethylenepentamine (TEPA).
5. The method of claim 2 , wherein the weight ratio of the azo compound to the amine activator is about 5:1 to about 1:5.