Halliburton Energy Services, Inc. (Houston, TX) inventors Craig W. Roddy and Ricky L. Covington developed well treatment fluids and methods utilizing nanoparticles as well as sealant compositions and methods utilizing nanoparticles for use in sealing oil and gas wells.
The nano-particles may be incorporated into the sealant composition in different forms, including as discrete nanoparticles, encapsulated nanoparticles, agglomerated nanoparticles, or in a liquid suspension, according to U.S. Patent Application 20100016183.
Halliburton’s sealant composition is comprised of nano-particles and water for use into a subterranean formation. The nano-particles may be at least about 75% by weight of dry particles in the sealant composition.
A variety of different sealant compositions may be used in subterranean operations. For example, in subterranean well construction, a pipe string (e.g., casing and liners) may be run into a well bore and cemented in place using a cement composition. The process of cementing the pipe string in place is commonly referred to as "primary cementing." In a typical primary cementing method, a cement composition may be pumped into an annulus between the walls of the well bore and the exterior surface of the pipe string disposed therein. The cement composition sets in the annular space, thereby forming an annular sheath of hardened, substantially impermeable cement that supports and positions the pipe string in the well bore and bonds the exterior surface of the pipe string to the subterranean formation.
Among other things, the annular sheath of set cement surrounding the pipe string should seal the annulus, preventing the migration of fluids in the annulus, as well as protecting the pipe string from corrosion. Cement compositions also may be used in remedial cementing methods, such as squeeze cementing, repairing casing strings and the placement of cement plugs. In squeeze cementing, for example, a cement composition may be used to plug off and seal undesirable flow passages in a cement sheath, casing, and/or gravel packs.
In some instances, cement compositions may be used to change the direction of the well bore, for example, by drilling a pilot hole in a hardened mass of cement, commonly referred to as a "kickoff plug," placed in the well bore. While a cement composition is one type of sealant composition that may be used in subterranean operations, other non-cement containing cement sealant compositions also may be employed. By way of example, polymeric sealant compositions also may be used.
