CN200946459Y

CN200946459Y - PDC drill with positive rake angle cutting structure

Info

Publication number: CN200946459Y
Application number: CN 200620113547
Authority: CN
Inventors: 王镇全; 朱益
Original assignee: China University of Petroleum Beijing
Current assignee: China University of Petroleum Beijing
Priority date: 2006-04-29
Filing date: 2006-04-29
Publication date: 2007-09-12
Anticipated expiration: 2016-04-29

Abstract

The utility model discloses a positive rake angle cutting structure PDC borer, which comprises a borer body and apolycrystalline diamond compact (PDC)cutting teeth arranged on the front end of the borer body, define the intersection point of the cutting surface of the compact cutting teeth and the borer body generatrix as the original point, the horizontal line through the original point as X axis, the right direction as the positive direction, the vertical line as Y axis, the upward direction as the positive direction, thus the XOY coordinate system forms, the compact cutting teeth appears in conical shape, the angle between the cutting surface of the compact cutting teeth and the Y axis negative direction is at the fourth quadrant of the coordinate, and the value is positive. During the using course of PDC borer, the rocks beneath the cutting surface are mainly reduced substantially to compressive stress to area, larger volume shear broken is easy to form, the rock-breaking effects of the PDC borer are improved, and the drilling speed is raised.

Description

The PDC drill bit of positive rake angle cutting structure

Technical field

The utility model relates to the PDC drill bit that a kind of oil, geology, coal drilling well are used, and more particularly, relates to a kind of PDC drill bit that improves the positive rake angle cutting structure of stock-removing efficiency and rate of penetration.

Background technology

As shown in Figure 1, the traditional PD C drill bit that is used for drilling well includes drill body 1 and cylindrical composite polycrystal-diamond cutting teeth 2, composite sheet cutting teeth 2 is fixed on the front end of drill body 1 by the mode of inlaying, this composite sheet cutting teeth 2 includes the hard alloy layer 20 of mutual formation one and by diamond layer 21, wherein hard alloy layer 20 is used to improve the intensity of cutting teeth 2, and provides support for diamond layer 21; Diamond layer 21 is used to cut rock stratum 3.The bus of definition drill body 1 is the Y-axis line, it more than is forward, the horizon vertical with bus is the X-axis line, with dextrad is forward, cutting face 22 with composite sheet cutting teeth 2 is an initial point with the point that drill body bus 10 intersects, form the XOY coordinate system, therefore the cutting face 22 of composite sheet cutting teeth 2 is positioned at third quadrant with the angle a of Y-axis line negative sense, be negative value, because this angle a is a negative value, therefore make drill bit cause cutting teeth rock before the tooth in the broken rock process of shearing to be subjected to multidirectional compressive state when cutting easily, rock-breaking efficiency is low, influences rate of penetration.

Summary of the invention

The purpose of this utility model is to provide a kind of PDC drill bit of positive rake angle cutting structure, the multidirectional compressive stress of the rock district that utilizes this PDC drill bit can make the cutting teeth bottom reduces, easily form the shearing-crushing of larger volume, improve the cutting rock breaking efficiency of PDC drill bit, significantly improve bit speed.

The PDC drill bit of positive rake angle cutting structure includes drill body and the composite polycrystal-diamond cutting teeth that is arranged on described drill body leading section in the utility model, the point that the cutting face of definition composite sheet cutting teeth and drill body bus intersect is an initial point, horizon by this initial point is the X-axis line, dextrad is forward, vertical line is the Y-axis line, upwards be forward, form the XOY coordinate system, it is conical that described composite sheet cutting teeth is, the angle of the cutting face of described composite sheet cutting teeth and Y-axis line negative sense is positioned at the four-quadrant of coordinate system, be on the occasion of.

Described composite sheet cutting teeth includes mutual composition one and is used to improve the hard alloy layer of cutting hardness and the diamond layer that is used to cut.

Described angle is in 0 to 20 degree.

Described angle the best is in 5 to 10 degree.

The PDC drill bit of positive rake angle cutting structure is by changing the alteration of form of composite sheet cutting teeth and the angle of composite sheet cutting teeth cutting face and Y-axis line negative sense in the utility model, make the PDC drill bit will reduce significantly in the multidirectional compressive stress of the rock district of cutting teeth bottom in use, it is broken easily to form breaking of larger volume, improve PDC bit cutting gear rock breaking efficiency, significantly improved bit speed.

Description of drawings

Fig. 1 is the cross-sectional schematic of existing PDC drill bit;

Fig. 2 is the cross-sectional schematic of PDC drill bit in the utility model;

Fig. 3 is the structural representation of composite polycrystal-diamond cutting teeth in the utility model.

The specific embodiment

The specific embodiment of the utility model is described in further detail below in conjunction with accompanying drawing.

PDC drill bit in the utility model adopts identical label to illustrate with the parts that existing drill bit has identical function and structure, and also is provided with the coordinate system shown in Fig. 1, therefore describes in detail no longer separately having parts shown in the same numeral and function.

As shown in Figure 2, the PDC drill bit of positive rake angle cutting structure includes a drill body 1 and the composite polycrystal-diamond cutting teeth 2 that is arranged on drill body 1 leading section in the utility model, wherein composite sheet cutting teeth 2 (also can pass through other modes by the mode of inlaying, this to one skilled in the art, belong to common practise, do not need any creative work just can realize, therefore explanation no longer separately.) be fixed on the front end of drill body 1.The global shape taper shape of composite sheet cutting teeth 2, include hard alloy layer 20 and the diamond layer 21 of forming one, as shown in Figure 3, combine the cutting face 22 of fixing back composite sheet cutting teeth 2 and the angle a of Y-axis line negative sense with drill body 1 and be positioned at four-quadrant, be on the occasion of (often claiming positive rake angle), and this angle a can be between 0 to 20 degree, and best angle is 5 to 10 degree.PDC drill bit in the utility model is by improving the angle of composite sheet cutting teeth cutting face and Y-axis line negative sense, make that the basifacial rock of cutting 3 multidirectional compressive stress districts significantly reduce in working angles, easily form the shearing-crushing of larger volume, and by change to composite sheet cutting teeth global shape, can make drill bit in use composite sheet cutting teeth rear portion (hard alloy layer) can not contact with rock, can not form and hinder composite sheet cutting teeth wedging stratum, thereby can improve the rock breaking efficiency of PDC drill bit, improve rate of penetration.

Claims

1. A PDC drill with a positive rake angle cutting structure, comprising a drill body and a polycrystalline diamond composite cutting tooth arranged at the front end of the drill body, defining the point where the cutting surface of the composite cutting tooth intersects with the generatrix of the drill body is the origin, the horizontal line passing through the origin is the X axis, the right direction is the positive direction, the vertical line is the Y axis, and the upward direction is the positive direction, forming an XOY coordinate system. It is characterized in that: the cutting teeth of the composite sheet are conical, and the The included angle between the cutting surface of the cutting tooth of the composite sheet and the negative direction of the Y axis is located in the fourth quadrant of the coordinate system and has a positive value.

2. According to the PDC drill bit of the positive rake angle cutting structure described in claim 1, it is characterized in that: the composite sheet cutting teeth include a cemented carbide layer that is integrated with each other for improving cutting strength and diamond for cutting layer.

3. The PDC drill bit with a positive rake angle cutting structure according to claim 1 or 2, wherein the included angle is within 0 to 20 degrees.

4. The PDC drill with a positive rake angle cutting structure according to claim 3, wherein the included angle is within 5 to 10 degrees.