Settable, form-filling loss circulation control compositions comprising in situ foamed non-hydraulic sorel cement systems and method of use
This document relates to settable, non-hydraulic foamed cement compositions comprising nitrogen gas-generating compositions used for loss circulation control.
1. A foamed cementitious composition, comprising:
magnesium oxide (MgO);
a salt selected from the group consisting of magnesium chloride (MgCl 2 ), magnesium sulfate (MgSO 4 ), ammonium hydrogen phosphate (NH 4 H 2 PO 4 ), and hydrates thereof;
a hydrazide or a semi-carbazide;
an oxidizer; and
a foam surfactant.
2. The composition of claim 1 , wherein the oxidizer is selected from the group consisting of peroxide, persulfate, percarbonate, perbromate, perborate salts of ammonium, alkali earth metals, and alkaline earth metals.
3. The composition of claim 1 , wherein the weight ratio of the hydrazide or semi-carbazide to the oxidizer is about 1:0.25 to about 1:5.
4. The composition of claim 1 , further comprising a viscosifier.