Drill bit having regenerative nanofilms

Abstract

A system of repairing and protecting a surface of a drill bit includes forming a drill bit body that includes a magnetized material or is otherwise magnetizable. The drill bit includes at least one cutting element and is operable to generate a magnetic field. A drilling fluid that includes magnetizable, regenerative particles is circulated through a drill string and wellbore in which the drill bit is deployed. The magnetic field attracts the regenerative particles to the surface of the drill bit body to occupy cracks and chips formed in the surface of the drill bit body, and to form a protective layer of the regenerative particles over the surface of the drill bit body.

We claim: 
     
         1 . A wellbore formation system comprising:
 a drill bit having at least one cutting element and a drill bit body comprising a magnetized material that generates a magnetic field extending to an exterior of the drill bit body;   a drilling fluid comprising magnetizable regenerative particles; and   a fluid flow path that guides the drilling fluid through a drill string and over a surface of the drill bit.   
     
     
         2 . The system of  claim 1  wherein, the regenerative particles comprise superparamagnetic nanoparticles. 
     
     
         3 . The system of  claim 2 , wherein the superparamagnetic nanoparticles comprise iron oxide. 
     
     
         4 . The system of  claim 1 , wherein the drill bit body is a matrix drill bit body, and wherein the matrix drill bit body comprises:
 a particulate phase and a binder material, the particulate phase comprising magnetic particles.   
     
     
         5 . The system of  claim 1 , further comprising:
 an electromagnet,   wherein the drill bit body is a matrix drill bit body comprising a particulate phase and a binder material, the particulate phase comprising ferromagnetic particles; and   wherein the drill bit body is magnetically coupled to the electromagnet.   
     
     
         6 . The system of  claim 1 , wherein the drill bit body is a matrix drill bit body, and wherein the matrix drill bit body comprises:
 a particulate phase and a binder material, the particulate phase comprising particles of rare earth magnet.   
     
     
         7 . The system of  claim 6 , wherein the rare earth magnet is selected from the group consisting of AlNiCo, a neodymium magnet, and a samarium-cobalt magnet. 
     
     
         8 . The system of  claim 1  wherein the drilling fluid is a water-based drilling fluid, and wherein the regenerative materials are functionalized for dissolution in water. 
     
     
         9 . The system of  claim 1  wherein the drilling fluid is an oil-based drilling fluid, and wherein the regenerative materials are functionalized for dissolution in oil. 
     
     
         10 . A method of preserving a drill bit surface, the method comprising:
 providing a drill bit having a magnetized drill bit body that generates a magnetic field extending to an exterior of the drill bit body;   operating the drill bit to form a wellbore; and   circulating a fluid over a surface of the drill bit body to regenerate a surface of the drill bit body, the fluid comprising regenerative materials that are magnetically attracted to the magnetized drill bit body.   
     
     
         11 . The method of  claim 10 , wherein the regenerative materials comprise iron oxide nanoparticles. 
     
     
         12 . The method of  claim 10 , wherein the regenerative materials comprise superparamagnetic particles. 
     
     
         13 . The method of  claim 10 , wherein the drill bit comprises a matrix drill bit body having a particulate phase component, a binder material, the particulate phase including tungsten carbide, and the magnetic particles. 
     
     
         14 . The method of  claim 13 , further comprising activating an electromagnet, wherein the magnetic particles comprise a ferromagnetic material that becomes magnetized in response to activation of the electromagnet. 
     
     
         15 . The method of  claim 10 , wherein the magnetic particles comprise particles of rare earth magnet selected from the group consisting of AlNiCo, neodymium magnet, and samarium-cobalt magnet. 
     
     
         16 . The method of  claim 10 , further comprising forming a protective film of the regenerative materials at a surface of the drill bit body by magnetically attracting the regenerative materials to the surface of the drill bit body. 
     
     
         17 . A method of manufacturing a drill bit body comprising:
 placing a particulate phase and a binder material into a mold, the particulate phase including tungsten carbide and magnetizable particles; and   sintering the particulate phase and the binder to form a drill bit body.   
     
     
         18 . The method of  claim 17 , further comprising cooling the drill bit body following the step of sintering the particulate phase and the binder to form the drill bit body; and, while cooling the drill bit body, applying a magnetic field to the drill bit body. 
     
     
         19 . The method of  claim 18 , wherein applying the magnetic field to the drill bit body comprises applying a magnetic field to the drill bit body when the magnetizable particles are at the Curie temperature. 
     
     
         20 . The method of  claim 17 , wherein the magnetizable particles comprise particles of rare earth magnet selected from the group consisting of AlNiCo magnet, a neodymium, and samarium-cobalt.