Settable compositions comprising cement kiln dust and methods of use

A method comprising:

• introducing a settable composition comprising cement kiln dust, an alkali aluminate, an alkali silicate, and an aqueous carrier fluid into a subterranean formation,
• wherein at least one of the alkali aluminate or the alkali silicate are encapsulated to retard gelation;
• releasing at least one of the encapsulated alkali aluminate and the encapsulated alkali silicate and contacting the cement kiln dust, the alkali aluminate, and the alkali silicate in the subterranean formation proximate to or within a lost circulation zone;
• and
• allowing the settable composition to set and thereby reduce fluid flow through a portion of the subterranean formation, wherein a portion of the settable composition sets to form a non-flowable gel while a minor portion of the settable composition remains an active free fluid in a flowable liquid state, the active free fluid penetrating further into the portion of the subterranean formation,
• wherein the introducing the settable composition comprises introducing the settable composition into the subterranean formation as a single stream.