A method of manufacturing a bit body, other drilling-related component, or other article of manufacture, including fabricating a particulate-based matrix and infiltrating the particulate-based matrix with a binder that includes cobalt or iron. The binder may be a cobalt alloy or an iron alloy. The particulate-based matrix may be disposed within a non-graphite mold. The particulate-based matrix and binder are placed within an induction coil and an alternating current is applied to the induction coil in order to directly heat the binder, permitting the binder to infiltrate or otherwise bind the particles of the matrix together. The molten binder may then be directionally cooled by forming a cooling zone around an end portion of the bit body and increasing the size of the cooling zone relative to the bit body. The invention also includes a bit body, other drilling-related component, or other article of manufacture which includes a particulate-based matrix that is bound together with a binder that includes iron or cobalt.
A method for forming a drill bit body is disclosed which comprises infiltrating powdered tungsten carbide with a binder alloy in a mold. The mold has therein at least one displacement adapted to form a mounting pad for a cutting element. The displacement comprises a substantially cylindrical body having a diameter selected to substantially conform to a radius of the cutting element and a projection adapted to form a relief groove under a position of a diamond table in the cutting element when the cutting element is mounted on the pad. The width of the relief groove is selected so that the relief groove extends back from an outer surface of the bit body at least about 40 percent of that portion of a thickness of the diamond table which does not extend past the outer surface.
Embodiments of the present invention include hybrid composite materials comprising a cemented carbide dispersed phase and a cemented carbide continuous phase. The contiguity ratio of the dispersed phase of embodiments may be less than or equal to 0.48. The hybrid composite material may have a hardness of the dispersed phase that is greater than the hardness of the continuous phase. For example, in certain embodiments of the hybrid composite material, the hardness of the dispersed phase is greater than or equal to 88 HRA and less than or equal to 95 HRA and the hardness of the continuous phase is greater than or equal to 78 and less than or equal to 91 HRA.Additional embodiments may include hybrid composite materials comprising a first cemented carbide dispersed phase wherein the volume fraction of the dispersed phase is less than 50 volume percent and a second cemented carbide continuous phase, wherein the contiguity ratio of the dispersed phase is less than or equal to 1.5 times the volume fraction of the dispersed phase in the composite material.The present invention also includes a method of making a hybrid cemented carbide composite by blending partially and/or fully sintered granules of the dispersed cemented carbide grade with "green" and/or unsintered granules of the continuous cemented carbide grade to provide a blend. The blend may then be consolidated to form a compact. Finally, the compact may be sintered to form a hybrid cemented carbide.
An abrasive wear-resistant material includes a matrix and sintered and cast tungsten carbide pellets. A device for use in drilling subterranean formations includes a first structure secured to a second structure with a bonding material. An abrasive wear-resistant material covers the bonding material. The first structure may include a drill bit body and the second structure may include a cutting element. A method for applying an abrasive wear-resistant material to a drill bit includes providing a bit, mixing sintered and cast tungsten carbide pellets in a matrix material to provide a pre-application material, heating the pre-application material to melt the matrix material, applying the pre-application material to the bit, and solidifying the material. A method for securing a cutting element to a bit body includes providing an abrasive wear-resistant material to a surface of a drill bit that covers a brazing alloy disposed between the cutting element and the bit body.
This invention relates to cutting inserts for earth boring bits comprising a cutting zone, wherein the cutting zone comprises first cemented hard particles and a body zone, wherein the body zone comprises second cemented hard particles. The first cemented hard particles may differ in at least one property from the second cemented hard particles. As used herein, the cemented hard particles means a material comprising hard particles in a binder. The hard particles may be at least one of a carbide, a nitride, a boride, a silicide, an oxide, and solid solutions thereof and the binder may be at least one metal selected from cobalt, nickel, iron and alloys of cobalt, nickel or iron.
The present invention generally relates to a method and an apparatus for drilling with casing. In one aspect, a method of drilling a wellbore with casing is provided, including placing a string of casing with a drill bit at the lower end thereof into a previously formed wellbore and urging the string of casing axially downward to form a new section of wellbore. The method further includes pumping fluid through the string of casing into an annulus formed between the casing string and the new section of wellbore. The method also includes diverting a portion of the fluid into an upper annulus in the previously formed wellbore. In another aspect, a method of drilling with casing to form a wellbore is provided. In yet another aspect, an apparatus for forming a wellbore is provided. In still another aspect, a method of casing a wellbore while drilling the wellbore is provided.
