Drill bit and method for directional drilling
AssigneeCanopus Drilling Solutions Holding B.V.
InventorJan Jette Blange
Life of this patent
Estimating the term…
Abstract
The invention provides a drill bit, methods, and a system for directional drilling of a subterranean earth formatting by simultaneous abrasive jet drilling and mechanical drilling by cutting It provides in subsequent rotations of the bit, consistently, simultaneous erosion and excavation of the borehole bottom. For example it provides differential hole making by providing more erosion in respective zones of the borehole bottom angularly extending continuously over respective opposing azimuthal ranges by the respective radially inwards and outwards abrasive jets than outside of these zones, for example such as to bring about substantially no excavation in these zones and/or predominant excavation by the cutters outside of these zones.
Claims24
A drill bit for directional drilling of a subterranean earth formation simultaneously by abrasive jet drilling and mechanical cutting,
- the drill bit being configured to create and deepen a borehole bottom in the shape of a cone encircled by a, radially connecting, annular groove,
- the cone in use of the drill bit axially facing a radially inwards center section of the drill bit around a central rotation axis of the drill bit,
- and the annular groove axially facing a radially outwards section of the drill bit,
- the drill bit comprising
- a cylindrical body having at one axial side of the drill bit, connectable to a drilling system for being rotated around the rotation axis, a fluid inlet port for receiving a stream of drilling fluid mixed with abrasive particles, and being, at a face of the drill bit at the other axial side of the drill bit, provided with
- three or more blades disposed on the body, the blades
- being angularly distributed evenly with respect to the rotation axis of the drill bit
- defining slots angularly between them, and
- each having two or more mechanical cutters provided thereon,
- the cutters being provided in positions which are radially offset from one another such, that the total of cutters together substantially covers the radial extension of the drill bit,
- wherein the drill bit further comprises
- two or more abrasive jet nozzles, each being
- fluidly connected to the fluid inlet port and having a respective opening at the face of the drill bit,
- suitable for jetting a respective part of the stream of fluid mixed with abrasive particles as an abrasive jet towards the borehole bottom, for impingement thereof, in a respective jetting direction,
- the abrasive jet nozzles comprising
- at least one center nozzle, each extending in the center section of the drill bit, having an opening close to the rotation axis such as to be positioned, oriented and configured for eroding the cone and a radially inwards part of the encircling annular groove of the borehole bottom, by jetting the abrasive jet from the rotation axis radially outwards to the radially inwards part of the groove of the borehole bottom for impingement of this radially inwards part ahead of the cutters that are facing the radially inwards part, the at least one center nozzle thereto each extending at a diametrical side with respect to the rotation axis which is opposite to that at which the abrasive jet jetted by the nozzle substantially extends,
- at least one gauge nozzle, each of which has an opening in the radially outwards section of the drill bit, and is furthermore oriented and configured for eroding a radially outwards part of the encircling groove of the borehole bottom, by jetting the abrasive jet from the radially outwards section of the drill bit to the radially outwards part of the annular groove of the borehole bottom for impingement of this radially outwards part ahead of the cutters facing the radially outwards part, the at least one gauge nozzle thereto each extending at a diametrical side with respect to the rotation axis which is the same as that at which the abrasive jet jetted by the nozzle substantially extends.
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A method for directional drilling of a borehole, with a borehole bottom in the shape of a cone encircled by an annular groove radially connecting with the cone, in a subterranean earth formation, the method comprising:
- providing a drill bit, a body of said drill bit accommodating, for jetting a stream of a drilling fluid mixed with abrasive particles supplied to the drill bit at one axial side of the drill bit, as abrasive jets to the borehole bottom, two or more abrasive jet nozzles forming respective outlets for said stream at a face of the drill bit at the other axial side thereof, and cutters of said drill bit being provided at the face of the drill bit, wherein
- the abrasive jet nozzles comprise at least one center nozzle positioned, oriented and configured for jetting an abrasive jet eroding the cone and an inwards part of the annular groove, and at least one gauge nozzle positioned, oriented and configured for jetting an abrasive jet eroding an outwards part of the annular groove,
- the abrasive jet nozzles being positioned, oriented and configured to jet the abrasive jets such that these together erode the borehole bottom over substantially the entire radial extension thereof, and
- the cutters are positioned, oriented and configured to together, at least without erosion by the abrasive jets, excavate the borehole bottom over substantially the entire radial extension thereof,
- supplying the stream to the abrasive jet nozzles through a fluid connection between the abrasive jet nozzles drill bit and a supply for the stream at an axial side of the drill bit opposite to the face,
- rotating the drill bit around the rotation axis thereof so as to deepen the borehole bottom, through, in subsequent rotations of the bit, simultaneous
- erosion of the borehole bottom by the respective abrasive jets of the stream, impinging the borehole bottom ahead of the cutters, and
- excavation of the borehole bottom by the cutters.
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The system according to claim 21,
- wherein the stream modulator is configured for modulating the stream at least when the stream as fed to the stream modulator has a substantially homogeneous concentration of abrasive particles.
Dependencies are inferred from the claim text.