CN201786266U - Thin-wall matrix drill bit - Google Patents

Abstract

A thin-wall matrix drill bit comprises a cylindrical drill bit core, an outer matrix covering and a drilling fluid passage, wherein the upper end of the drill bit core is welded to the lower end of a milling tube, the lower portion of the drill bit core is thinned, the outer matrix covering covered on the lower portion of the thinned drill bit core forms a working molded surface of the drill bit, the drilling fluid passage arranged on the inner wall of the drill bit extends downwards to the outer side of the drill bit, and communicating structures are arranged on the lower portion of the thinned drill bit core, close to the lower edge of the drill bit core and along the circumference of the drill bit core. The communicating structures adopt communicating holes or run-through stress slots which are arranged at the same interval, or adopts the communicating holes and the run-through stress slots together. The run-through stress slots are open to the lower edge of the lower portion of the drill bit core.

Description

The thin-walled matrix drill bit

Technical field

The utility model relates to oil gas probing exploitation field, more particularly, relates to and is used to handle down-hole accident overlaps a kind of thin-walled matrix drill bit that mills in the probing recovery process of oil gas.

Background technology

In boring, completion and the well workover of oil gas well, utilize drilling tool in well, to carry out underground work usually with the wear-resisting work profile that acts on mutually with underground structure.Carrying out these operating periods; the work type face portion of drill bit is subjected to very large active force and stress; for example concerning the milling part that is installed in the drill bit bottom, it can be subjected to the tractive of acting surface on every side usually, and is subjected to the effect of the moment of torsion of coupled drive division.It is under moment of torsion that the drill bit core body transmitted and the effect of work plane on every side and be easy to cracking or split away off from the drill bit core body like this.Thereby cause cover to mill inefficacy.

Another kind of situation is, have in the manufacturing process of drill bit of wear-resisting work type face portion in the drill bit bottom, in its sintering cooling procedure, because drill bit core body and work type face portion are because of the different thermal expansion coefficient differences that exist of its material therefor, therefore, the work type face portion is easy to by the drawing crack of drill bit core body, perhaps peels off mutually with the drill bit core body owing to the effect of stress, and makes this drill bit effectively to use again.

For example, the thin-walled matrix drill bit that has shown a kind of the above-mentioned type of the prior art in the accompanying drawing 1, wherein, the drill bit core body of being made by steel core 3 links to each other with milling pipe 1 by conventional welding manner (having shown weld seam 2 among the figure), in addition, this milling pipe 1 also is threadably engaged portion 7 and drill bit core body and links to each other and keep being connected between the two, and adopting the purpose that is threaded is the centering that guarantees steel core.Carcass surrounding layer 4 sintering of the drill bit core body bottom of thickness attenuation and conduct work profile together.The drilling fluid that is called " drilling mud " is delivered to drill bit with lubricated and cooling drill bit by runner 6 via drill string pump (not shown), and just the circulation of the landwaste that produces of drill bit by mud is delivered to ground.

Drill bit shown in Fig. 1 removes to have above-mentioned carcass surrounding layer and produces drawing crack or peel off in the cooling sintering process on the drill bit core body, perhaps in the drill bit use, split away off outside such defective from the drill bit core body, also has following defective, promptly, make the steel core of this threaded connection compare relative thinner with the situation that does not have screw thread like this owing to adopt between the drill bit core body of making by steel core and the milling pipe and be threaded.In the drill bit course of work, because the moment of torsion that is delivered on the steel core of milling pipe is sizable, therefore, the situation of the torsional rigidity of this threaded connection when not having threaded connection compared, and drill bit of the prior art is easy to produce at this part place the steel core fracture.

Therefore, the purpose of this utility model is provides a kind of thin-walled matrix drill bit that can eliminate above-mentioned defective, it has increased the torsional strength of whole drill bit, and make the work type face portion to link to each other with the drill bit core body securely, and can or not be subjected to splitting away off in sintering process than generation cracking in the course of work of active force around big or from the drill bit core body.

The utility model content

Above-mentioned purpose is achieved through the following technical solutions.

In the utility model, only adopt the mode of welding to be connected between columnar milling pipe lower end and the columnar drill bit core body upper end and moment of torsion is passed to the drill bit core body by weld seam, and inwall, the outer wall of the inwall of milling pipe, outer wall and drill bit core body flush, preferred situation is that the weld seam between the two is trapezoidal weld seam.The bottom thickness attenuation of drill bit core body, the carcass surrounding layer (it forms the work type face portion in the drill bit use) that adopts different materials to make with the drill bit core body coats this thickness attenuation part of drill bit core body bottom and is sintered to one, be provided with connectivity structure with the mutually close position of drill bit core body lower edge, it makes and is in that the drill bit core body is inboard to link to each other with the carcass surrounding layer in the outside.The drill bit core body that makes carcass surrounding layer and its be coated like this is entirely formed as one, thereby has avoided the generation of stress, and has increased the torsional rigidity of carcass surrounding layer and it can not split away off from the drill bit core body.

Preferably situation is, described drill bit core body is formed from steel, and described carcass surrounding layer is made by the antifriction metal (AFM) alloy.

Preferred situation is that described connectivity structure is by circumferentially forming with the spaced apart a plurality of corresponding intercommunicating pores that equate along bit body.

Preferred situation is, described connectivity structure is by being arranged on the described drill bit core body bottom and forming at the perforation stress groove of the lower edge opening of this bottom, and these connect stress grooves in the upwards interval setting to equate of the week of bit body.Make described carcass surrounding layer not only coat the bottom of the attenuation of described drill bit core body like this, but also partly embed in this bottom, avoided the generation of stress like this, and the two is formed as one better.

Preferred situation is, circumferentially arrange intercommunicating pore in upper edge, described drill bit core body bottom simultaneously and connect the stress groove, arrange with the interval that equates between the described intercommunicating pore, and also arrange that with the interval that equates described perforation stress groove is at the lower edge opening of drill bit core body bottom between the described perforation stress groove.

Description of drawings

Figure 1 shows that the structure sectional view of thin-walled matrix drill bit of the prior art;

Figure 2 shows that the structure sectional view of the application's thin-walled matrix drill bit;

Figure 3 shows that the sectional view that the application's thin-walled matrix drill bit is done along the intercommunicating pore center line, shown the distribution situation of intercommunicating pore among the figure in the drill bit core body bottom of thickness attenuation, intercommunicating pore wherein can adopt the perforation stress groove at drill bit core body lower limb opening to substitute (for simplifying the application's description, herein not to only adopting the situation that connects the stress groove to show);

Fig. 4 has shown on the drill bit core body bottom of thickness attenuation the situation that not only intercommunicating pore is set but also the stress groove is set, intercommunicating pore wherein and stress groove along circumferential arrangement on drill bit core body bottom.

The specific embodiment

Accompanying drawing 1-4 has carried out concrete demonstration to the thin-walled matrix drill bit according to the application.What Reference numeral wherein was indicated thes contents are as follows: 1---milling pipe; 2---weld seam; 3---the drill bit core body; 4-carcass surrounding layer; 5---intercommunicating pore; 6---the drilling fluid runner; 8---connect the stress groove.

As shown in Figure 2, in the application's thin-walled matrix drill bit, only adopt the mode of welding to be connected between the end of the end of cylindrical shape milling pipe 1 and cylindrical shape drill bit core body 3 and moment of torsion is passed to drill bit core body 3 by weld seam 2, and inwall, the outer wall of the inwall of milling pipe 1, outer wall and drill bit core body 3 flush respectively, drill bit core body 3 adopts steel to make in this embodiment, and it can adopt the material with similar performance according to purposes and application target certainly.Above-mentioned weld seam is preferably trapezoidal weld seam.

The bottom thickness attenuation of drill bit core body 3, and adopt a carcass surrounding layer 4 to coat this thickness attenuation part, this carcass surrounding layer forms the work type face portion of drill bit.This carcass surrounding layer 4 is made by the material different with drill bit core body 3, and it adopts the antifriction metal (AFM) alloy in this application, but the application is not limited in this, as long as this material can satisfy the anti-wear performance that is suitable for using in the drill bit and then can.The two sintering is together in manufacture process for carcass surrounding layer 4 and drill bit core body 3.

partly locate to be furnished with a plurality of intercommunicating pores 5 with the interval that equates near the thickness attenuation of drill bit core body 3 lower limbs along the circumferential of drill bit, shown the circumferential deployment scenarios of intercommunicating pore 5 among Fig. 3 along drill bit, the number of intercommunicating pore is decided according to concrete operating mode needs.In the manufacture process of drill bit, the part material of carcass surrounding layer 4 passes described intercommunicating pore 5 and makes and be in that drill bit core body 3 is inboard to link to each other with the carcass surrounding layer (it is called the work type face portion in the drill bit use) in the outside.Make carcass surrounding layer 4 not only coat the part of drill bit core body bottom thickness attenuation like this from the outside, but also pass the intercommunicating pore in this thickness attenuation part and be entirely formed as one with drill bit core body 3, thereby avoided the generation of stress, and increased carcass surrounding layer 4 (work type face portion) when work torsional rigidity and it can not split away off from drill bit core body 3.

Alternatively, can adopt along the perforation stress groove 8 that circumferentially is arranged on the described thickness attenuation part of drill bit core body of drill bit and substitute described intercommunicating pore with the interval that equates, this connects the 8 edge upper sheds in drill bit core body bottom of stress groove, and promptly the intercommunicating pore shown in the accompanying drawing 35 adopts perforation stress groove 8 to substitute.The carcass surrounding layer 4 that is arranged so that of this perforation stress groove not only coats the bottom of the attenuation of described drill bit core body 3, but also is partially submerged in this bottom, has avoided the generation of stress like this, and the two is formed as one better.

In addition, also can circumferentially arrange intercommunicating pore 5 in the upper edge, bottom of described drill bit core body 3 attenuation simultaneously and connect stress groove 8, promptly schematically shown this situation in the accompanying drawing 4, wherein, arrange with the interval that equates between the described intercommunicating pore 5, and also arrange between the described perforation stress groove 8 with the interval that equates.Each other interval of intercommunicating pore 5, connect stress groove 8 interval and intercommunicating pore 5 each other and decide according to practical application with the interval between the perforation stress groove 8.The application there is no particular restriction to this.

On the inside and outside wall of this drill bit, be furnished with drilling fluid runner 6, the drilling fluid that is called " drilling mud " is delivered to drill bit with lubricated and cooling drill bit by this drilling fluid runner 6 via drill string pump (not shown), and the circulation of the landwaste that drill bit is produced by mud is delivered to ground.Although below with reference to a specific embodiment of the present invention the utility model is described, the utility model is not limited to above-described embodiment.Those skilled in the art can make a change the foregoing description and changes according to above instruction.With reference to following claim the scope of present embodiment is made qualification.

Claims (6)

1. thin-walled matrix drill bit, it comprises: columnar drill bit core body (3), the upper end of this drill bit core body are welded on cylindrical shape milling pipe (1) lower end, the bottom thickness attenuation of this drill bit core body; Be coated on the carcass surrounding layer (4) on the drill bit core body bottom of this thickness attenuation, it forms the work type face portion of drill bit; Be arranged on the drilling fluid runner (6) on the drill bit inner and outer wall, it is characterized in that: on the drill bit core body bottom of thickness attenuation, be provided with connectivity structure near its lower edge.

2. thin-walled matrix drill bit according to claim 1 is characterized in that, formed weld seam (2) is trapezoidal weld seam between the lower end of the upper end of described drill bit core body (3) and milling pipe (1).

3. thin-walled matrix drill bit according to claim 1 is characterized in that, described connectivity structure is by circumferentially constituting with the spaced apart a plurality of intercommunicating pores (5) that equate along drill bit.

4. thin-walled matrix drill bit according to claim 1 is characterized in that, described connectivity structure is made of a plurality of perforation stress grooves (8) at drill bit core body lower edge opening, and described a plurality of perforation stress grooves (8) circumferentially are provided with the interval that equates along drill bit.

5. thin-walled matrix drill bit according to claim 1, it is characterized in that, described connectivity structure is by circumferentially circumferentially constituting with a plurality of perforation stress grooves (8) that the interval that equates is provided with a plurality of intercommunicating pores (5) of equal interval setting and along drill bit along drill bit, and described perforation stress groove (8) is all at drill bit core body lower edge opening.

6. according to the described thin-walled matrix drill bit of one of claim 1-5, it is characterized in that described drill bit core body (3) is formed from steel, and described carcass surrounding layer (4) is made by the antifriction metal (AFM) alloy.

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