Background technology
Drill bit is direct in drilling process and rock contact, by the instrument of the effect fractured rocks such as cutting, punching press.In modern drilling engineering, widely used drill bit mainly contains rock bit, PDC drill bit (Polycrystalline Diamond Compact Bits polycrystalline diamond compact bit).Now, rock bit and PDC drill bit have developed into quite high level all, but still there are some unsurmountable problems.One is be afraid of reaming and reaming hole, and make the rock bit of sealed bearing, particularly PDC drill bit damages in advance; Two is little to the motion of center, shaft bottom rock, insufficiency of function, and center rock is not easily broken, affects the rate of penetration of drill bit, rock bit and PDC bit central cloth tooth few, easy to wear, be also drill bit lost efficacy main cause.Below respectively the relevant tricone bit of background of the present invention, single-cone rotary drill bit, PDC drill bit, composite drill bit feature are analyzed.
Tricone bit: break rock form when tricone bit creeps into and crush broken rock for impacting, by the tooth on gear wheel, granulitization fractured rock is impacted to bottom rock formation, form hole diameter (see Figure 15).Because the compressive strength of rock is much larger than shearing resistance and tensile strength, and tricone bit utilizes the percussion of tooth to rock to carry out brokenly rock, and capacity usage ratio is not high.Particularly in the contour the pressure of the drill situation of deep drilling, due to the effect of highdensity drilling fluid, the cuttings hold-down effect in shaft bottom is obvious, and drill teeth is difficult to impact grinding rock, therefore efficiency of breaking rock is relatively low.
Tricone bit bearing life is one of principal element of restriction drilling life of bit, bearing bears the load that the pressure of the drill causes, add that tricone bit breaks rock with impulse form, the shock loading that bearing is subject to is large, load amplitude is high, in addition the speed(-)up effect of tricone bit: the tricone bit wheel body speed ratio ratio of gear wheel rotating speed and drill speed (during the drilling well) is greater than 1, namely when drill bit creeps into, gear wheel rotating speed is greater than drill bit drilling speed, so bearing rotating speed is relatively very fast, cause the bearing life of tricone bit shorter.
From tricone bit rock break-off process and gripper path analysis, the tooth on gear wheel and shaft bottom rock of borehole less for time of contact, tooth is also less in the distance of shaft bottom slippage, have impact on drilling efficiency.
Single-cone rotary drill bit: single-cone rotary drill bit is then rely on impact, the roll extrusion of tooth formation and scrape to cut three kinds of mode fractured rocks, especially the direction of cutting motion is scraped all different at each position on gear wheel surface, namely the tooth of different row in shaft bottom along the track of different directions, stratum is cut in the slippage making longer distance, and the webbed well-bottom trace of shape (see Figure 16).The feature of single-cone rotary drill bit is that gear wheel rotating speed is low, bearing size is larger, application life is better than tricone bit, but single-cone rotary drill bit has the shortcoming that cannot avoid: meeting the eye on every side in its rock break-off process of structures shape of single-cone rotary drill bit easily occurs to repeat fragmentation, chip removal difficulty.Tooth abrasion resistance wretched insufficiency, once there is tooth blunt or broken teeth, rate of penetration sharply declines.
PDC drill bit: it is scraping rock that PDC drill bit breaks rock form, use more and more extensive in drilling well, geology and even construction work, the ratio used in drilling engineering is increasing.Under the ideal operation condition that center line of bit and hole axis overlap, when drill bit creeps into, the movement locus of each cutting teeth is relatively-stationary concentric circles endless belt (see Figure 17).Due to its rock breaking mechanism and architectural difference, PDC drill bit is applicable to higher drilling speed and soft to medium ground.Its deficiency mainly contains following aspect:
(1) downhole condition requires high: if there is foreign matter in shaft bottom, PDC drill bit can be caused to produce and collapse tooth or thermal friction phenomenon, and temperature raises burns black carcass, even melts brazing layer, produces tooth phenomenon, affect rate of penetration, accelerates drill bit and loses efficacy.
(2) serious consequence of PDC tooth inefficacy: compared with rock bit, the inefficacy (fall tooth, collapse tooth etc.) of the indivedual tooth of PDC drill bit seriously can increase the load of neighbouring PDC tooth, accelerates its rate of wear, aggravates drill bit and loses efficacy.
(3) heart portion efficiency of breaking rock is not high: the rate of wear difference of the PDC tooth on the different radial zone of PDC drill bit is obvious, and outer shoulder rock cutting ratio is large, and the rate of wear is fast.Heart portion PDC tooth contact efficiency of breaking rock is low, weares and teares then slower.
The composite drill bit of rock bit+rock bit: this type composite drill bit is by rock bit and rock bit compound, and well center and well periphery complete by rock bit tooth.Have multiple complex form, application scenario comprises in reaming, no-dig technique, and its deficiency mainly contains:
(1) center efficiency of breaking rock is not high: because composite drill bit is made up of rock bit, and its broken rock form is still impact grinding, and capacity usage ratio is not high.The same with rock bit, in high the pressure of the drill situation, due to the effect of highdensity drilling fluid, the cuttings hold-down effect in shaft bottom is obvious, and drill teeth is difficult to impact grinding rock, and efficiency of breaking rock is relatively low, especially well centre, and situation is even more serious.
(2) the peripheral bit wear of well is serious: this type composite drill bit well periphery, cone bit cone size is relatively little, but drilling process rotating speed is high, can accelerate wearing and tearing and the inefficacy of drill bit, causes drill bit to occur back of the body phenomenon of grinding one's teeth in sleep simultaneously.
(3) center and peripheral gear wheel life-span are not etc., the composite drill bit life-span is not high: based on rock breaking mechanism and the structure composition of this type composite drill bit, center efficiency of breaking rock is not high, and the cone structure size of well periphery is little, rotating speed is high, serious wear, cause the rock bit aging variation of well center and well periphery, be difficult to realize composite drill bit global optimization and life-span raising.
The composite drill bit of drag bit+rock bit: when considering roller bit cutting shale and other flowing rock formations, chip hold down easily causes shaft bottom mud drum, along with the increase of boring dark and bottom pressure and mud balance, mud drum phenomenon can be more serious.And drag bit or fixed cutter drill bits affect less by this, in initial stage compound, these two kinds of drill bits are combined, simply drag bit and rock bit are combined, because bit wing alar part can cause rate of penetration even lower than rock bit by premature wear, this structure does not finally realize commercialization.
Dynamic stability composite drill bit: gear wheel and PDC drill bit are combined, its design is based on four wings and six wing PDC drill bit structures, and secondary wing position is substituted by the gear wheel of short size.The PDC cutting teeth crept into by being positioned on the operator wing of well center completes brokenly rock, and creeping into of well periphery complete jointly by gear wheel and PDC cutting teeth.This structure carry out drilling speed improve (creep in shale or other plastic formations, drilling speed than rock bit improve 2 ~ 4 times.Rate of penetration in abrasive hardcoat stratum is about 2 times of gear wheel, 1.5 times of PDC).This composite drill bit center is broken rock and is completed by wing, still can not change the phenomenon that PDC bit central efficiency of breaking rock is low.Rotary drill simultaneously in composite drill bit remains great circle and cuts well periphery, and little gear ring cuts well centre, effectively can not improve bearing size, improves bit life.
Summary of the invention
The present invention's design has the composite drill bit of rotary cut rock-breaking function, comprises rotary-cut drill bit and PDC drill bit compound, rotary-cut drill bit and rock bit compound, rotary-cut drill bit and rotary-cut drill bit compound.Rotary-cut Cutter in composite drill bit is with rotary cutting mode impact, crushing, rock cutting, realize broken rock, center efficiency of breaking rock is high, rate of penetration is high, there is better dynamic performance, even wearing, improve bit bearing structure simultaneously, increase drilling life of bit while guaranteeing to improve efficiency of breaking rock, gauge is effective; Composite constructions different in composite drill bit can realize center and break the effect that lithology energy is high, rate of penetration is high, gauge is effective.
For realizing the object of the invention, adopt following technical scheme:
There is the composite drill bit of rotary cut rock-breaking function, comprise drill main body, it is characterized in that: composite drill bit is by least one compound in rotary-cut drill bit and rock bit, PDC drill bit, rotary-cut drill bit, the installed surface of the rotary-cut gear wheel (2) of rotary-cut drill bit is connected with the gear wheel axle journal on drill main body (1), and the work plane of rotary-cut gear wheel is towards the borehole wall and shaft bottom; Gear wheel axle journal plane and drill axis angle and wheel body anglescope be, axle journal side-play amountscope be, whereinfor rotary-cut bit diameter.
Aforementioned rotary-cut gear wheel work plane refers to taper seat gear wheel being arranged chip tooth, and installed surface is on the direction, bottom surface of this conical surface.
The design feature of the rotary-cut drill bit in composite drill bit of the present invention comprises:
(1) with a rotary-cut drill bit for breaking rock by rotary cutting, main body (1), rotary-cut bit cone (2), rotary-cut Cutter (3) is comprised.Described rotary-cut drill bit at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1), its wheel body anglescope be(compriseand), axle journal side-play amountscope be(compriseand), wherein, rotary-cut bit conecorresponding wheel body angle is, wheelcorresponding axle journal side-play amount is,for rotary-cut bit diameter.
(2) rotary-cut bit cone: rotary-cut bit cone (2) is steel part, the sintered body of steel body and metal dust; Described rotary-cut bit cone (2) structure has the sintering gear wheel of mill teeth gear wheel, insert cone, steel body and metal dust; Described rotary-cut bit cone (2) number >=1.
(3) rotary-cut Cutter: rotary-cut Cutter (3) shape comprises scoop chisel insert, chisel teeth, blunt conical-ended shape insert, hemi-spherical ended shape insert, frustum tooth, cylinder butt tooth, pyramid tooth; Described rotary-cut Cutter (3) material comprises carbide alloy, polycrystalline diamond complex, TSP, impregnated with diamond, natural diamond, cubic boron nitride, pottery, and comprises the cutting teeth of carbide alloy, diamond or cubic boron nitride; Described rotary-cut Cutter (3) gear ring number >=1.
Rotary-cut drill bit in composite drill bit of the present invention is by gear wheel towards the borehole wall or shaft bottom, and in rock break-off process, inner row teeth (i.e. great circle tooth) center, machinable shaft bottom, improves center efficiency of breaking rock; Often circle tooth on gear wheel can impact to crush with rotary cutting mode and cut shaft bottom and rock of borehole, and this is the core of rotary-cut drill bit in the present invention.
According to foregoing invention, manufacture experimently out rotary-cut simulation drill bit in September, 2010, and tested on stand.The shaft bottom profile that the shaft bottom profile (see Figure 14) that rotary-cut drill bit gets out and tricone bit and PDC drill bit get out is completely different.The zone of fracture of tricone bit and PDC drill bit is all concentric circles (see Figure 15 and Figure 17), and in composite drill bit of the present invention the zone of fracture of rotary-cut drill bit be into the helix of chrysanthemum shape.Helix is intensive and disappear at borehole wall place, and on sufficient proof gear wheel, each toothrow can cut shaft bottom and the borehole wall, forms hole diameter.Inner row teeth zone of fracture spiral line length, outer rows of teeth zone of fracture helix is short, and the workload of interior outer rows of teeth can be made more even.
The zone of fracture of helix, illustrates rotary-cut drill bit rock breaking mechanism, and the existing impact granulitization of every toothrow, again can rock cutting.Improve center efficiency of breaking rock simultaneously, thus improve drill bit rate of penetration.
Because rotary-cut drill bit breaks rock mode feature, so various drilling well needs can be adapted to, in sidetracking and horizontal well drilling than existing rock bit and diamond bit more superior.
According to above analysis, axle journal deviantincrease, the radial slippage of cutting teeth in shaft bottom and circumferential slippage can be increased, namely increase the total slippage of cutting teeth in shaft bottom.Wheel body anglespan is:, axle journal deviantspan is:, cutting teeth can be realized better with breaking rock by rotary cutting.Optimizewith, can reach and increase gear wheel cutting teeth in shaft bottom and borehole wall slippage, reduce the object of wheel body speed ratio.
The performance characteristics of the rotary-cut drill bit in composite drill bit of the present invention comprises:
(1) breaking rock by rotary cutting: in the rotary-cut drill bit drilling process in composite drill bit of the present invention, the gear wheel axle journal in main body (1) points to the borehole wall or shaft bottom, hands over an angle to offset again drill axis (namely with rotary-cut drill axis,) time, rotary-cut bit cone (2), with rotary cutting mode impact, crushing, rock cutting, realizes broken rock and creeps into.Drilling process rotary-cut Cutter (3) not only rolls along with gear wheel, forms the crushing of formation, and cut stratum by its slipping in shaft bottom, efficiency of breaking rock is high simultaneously.According to different drilling well demands, change wheel body angle, axle journal deviantand gear wheel (2) size and dimension, each row's cutting teeth (3) on gear wheel (2) can be made all to be cut to corresponding well center, well edge and the borehole wall, the bottom hole pattern of requirement can also be got out.
(2) center break lithology can be high: in drilling process, the well center that rotary-cut drill bit is corresponding is completed by great circle tooth, due to bull gear largest diameter in rotary-cut bit cutting gear ring, the number of teeth many (many more than 6 times of comparable tricone bit central authorities cloth tooth), relative cutting speed is high, fundamentally can solve present tricone bit and the low problem of PDC drill bit heart portion efficiency of breaking rock.
(3) rate of penetration improves: (key parameter comprises wheel body angle to the structure of rotary-cut drill bitwith axle journal deviant) determine its broken rock form for impacting, smash, shear action, simultaneously corresponding well center efficiency of breaking rock and aggressive height, avoid the problem of meeting the eye on every side and repeat Fragmentation Phenomena, being beneficial to chip removal, raising drill bit rate of penetration.
(4) better dynamic performance: break petrofacies ratio with rock bit impulse form, the broken rock form of rotary-cut drill bit for impacting, smashing, shear action, the shock loading that continuous print shear action makes drill bit be subject to is little, load amplitude reduction.Simultaneously the rotary-cut drill bit wheel body speed ratio ratio of drill speed (the gear wheel rotating speed with) is less than 1, and when namely drill bit creeps into, gear wheel rotating speed is less than drill bit drilling speed, so bearing rotating speed is relatively slow, rotary-cut drill vibration impacts and reduces.Compared with common PDC drill bit, rotary-cut drill bit torsional oscillation reduces, and the well spiral phenomenon under the stick-slip under the slow-speed of revolution and high rotating speed reduces.In the platform experiment result that the present invention carries out, also demonstrate with same size, with compared with the rock bit under working condition, PDC drill bit, rotary-cut drill bit possesses These characteristics.Better dynamic performance makes rotary-cut drill bit have the larger scope of application and better control ability.
(5) wheel body speed ratio is less than 1, bearing life improvement of terms, rotary-cut bit life improve: the wheel body speed ratio of rotary-cut drill bit is less than 1, and the journal size of gear wheel can design larger than the tricone bit of same specification, have a clear superiority in than rock bit in the intensity and drilling life of bit of axle journal.The rotary-cut drill bit of composite drill bit of the present invention is in rock break-off process, shaft bottom and the borehole wall are close to axle journal plane to the promotion gear wheel of making a concerted effort that drill bit produces, this is conducive to improving bearing seal performance, improve bearing application life, based on the significance of bearing life for drill bit, thus realize the raising of rotary-cut bit life.
(6) gauge effect: all cutting gear rings of rotary-cut drill bit can cut shaft bottom and the borehole wall, forms hole diameter.If that circle odontotripsis cutting the borehole wall at first shortens, the second circle tooth will take over the work of first lap tooth, and realize gauge, unlikely boring is more and more less.If the second circle tooth also wear out failure, the 3rd circle tooth still can realize gauge, by that analogy.Rotary-cut drill bit due to composite drill bit of the present invention has all gear rings can cut the corresponding hole diameter of rotary-cut drill bit, and make it have the gauge less than tricone bit and sidetracking ability, gauge is effective.
In the present invention, composite drill bit is according to rotary-cut drill bit, PDC drill bit, composite construction that rock bit is different, can realize corresponding object.Be analyzed as follows for wherein two kinds of composite drill bit types:
Analyze for rotary-cut drill bit in the present invention (well center and well periphery) the secondary wing of+PDC drill bit (well is peripheral) composite drill bit, wherein composite drill bit is based on rotary-cut drill bit structure, is trapped among the secondary wing of PDC Bit between rotary-cut bit cone outside well.In drilling process, creeping into of well center is completed by rotary-cut Cutter, and creeping into of well periphery is completed jointly by rotary-cut drill bit and PDC Cutter.It has following characteristics:
(1) strengthen peripheral broken rock: in rotary-cut drill bit drilling process, with rotary cutting mode impact, crushing, rock cutting, realize creeping into, and peripheral near borehole wall annex, based on shear action.This type composite drill bit is the secondary wing of PDC Bit between well periphery, rotary-cut bit cone, strengthens peripheral rock breaking capacity, the peripheral efficiency of breaking rock of raising, raising rate of penetration further, reduces the wearing and tearing of peripheral cutting teeth simultaneously, increases bit life.
(2) gauge effect is strengthened further: can realize by rotary-cut drill bit drilling process the feature that all gear rings can cut shaft bottom and the borehole wall, in this type structure, periphery is born part by the secondary wing cutting teeth of PDC and is cut task, while reduction rotary-cut drill bit rotary-cut odontotripsis, the gauge ability of composite drill bit and effect are further strengthened.
(3) drilling process stability is strengthened: composite drill bit, with rotary-cut drill bit compared with, distribute more extensively with shaft bottom and borehole wall Contact Tooth number and increase, contact point, the stability of increase drilling process.
(4) be more suitable for sidetracking, directional well operation: on the basis that stability increases, this type composite drill bit cuts more steady, namely has better control ability, so applicability is further increased in the operation such as sidetracking, directional well.
Analyze for rotary-cut drill bit in the present invention (well peripheral)+PDC drill bit (well center is peripheral with well) composite drill bit, wherein composite drill bit is based on the PDC drill bit structure of four wings or six wings, and well is peripheral replaces secondary wing by rotary-cut drill bit.In drilling process, the PDC cutting teeth crept into by being positioned on the operator wing of well center completes, and creeping into of well periphery is completed jointly by rotary-cut drill bit and PDC Cutter.It has following characteristics:
(1) efficiency of breaking rock and rate of penetration is improved: rotary-cut drill bit is with rotary cutting mode impact, crushing, rock cutting, PDC Cutter scrapes the Cutting trajectory cutting out concentric circles in shaft bottom, and the zone of fracture of rotary-cut drill bit is into the helix of chrysanthemum shape, helix is intensive and disappear at borehole wall place.The staggered effect of two kinds of Cutting trajectories, effectively improves the efficiency of breaking rock of drill bit.
(2) reduce PDC thermal friction phenomenon: the alternately cutwork mode of the cutting teeth on gear wheel is conducive to the cooling of cutting teeth (particularly PDC tooth), avoid or reduce and generation of the thermal wear phenomenon of cause wear and tear aggravation too high due to temperature.
(3) cutting teeth even wearing: PDC Cutter rate of wear difference is fairly obvious, exterior zone cutter-wear rate is obviously faster than heart portion region tooth.In this structure, rotary-cut Cutter can play special booster action to the easy to wear of PDC Cutter and failed areas, while this composite drill bit structure realizes the even wearing of rotary-cut drill bit and PDC Cutter, significantly improve the working life of composite drill bit.
(4) bit life is improved
For rotary-cut drill bit, needed for rotary-cut drill bit, the pressure of the drill is relatively little, and Fluctuation of weight on bit amplitude is less; Wheel body speed ratio is less than 1; Bearing size improvement of terms, the journal size of gear wheel can design larger than the tricone bit of same specification; Shaft bottom and the borehole wall making a concerted effort of producing promote gear wheel to drill bit and are close to axle journal plane, are conducive to improving bearing seal performance, and improve bearing application life, thus combined bits can reach the bearing life higher than tricone bit.
For PDC drill bit, increase the working life that cutter set density can increase drill bit, but also can reduce drill bit rate of penetration.In the present invention, cutting teeth alternation while rotary-cut Cutter adds cutting teeth quantity.Namely rotary-cut drill bit can, while increase total cutting number of teeth, keep the work number of teeth constant or substantially constant.Its effect keeping drill bit rate of penetration while, the working life of drill bit is extended, and alleviates in drill bit design the contradiction extending bit life and improve between drilling speed.
According to above research, in the present invention, its structure types of composite drill bit and performance characteristics are including (but not limited to) following content:
(1) multiple complex form: with the composite drill bit of breaking rock by rotary cutting in the present invention, is made up of rotary-cut drill bit, PDC drill bit, rock bit, comprises main body (1), rotary-cut bit cone (2), rotary-cut Cutter (3).It is characterized in that: in composite drill bit, at least comprise a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Composite drill bit complex form comprises rotary-cut drill bit and PDC drill bit compound, rotary-cut drill bit and rock bit compound, rotary-cut drill bit and rotary-cut drill bit compound.Utilize the performance characteristics of rotary-cut drill bit, composite drill bit center is made up of rotary-cut drill bit, then, in drilling process, well center is crept into and completed by rotary-cut Cutter, can realize composite drill bit center and break the object that lithology energy is high, rate of penetration is high.Composite drill bit well periphery is made up of rotary-cut drill bit (or rotary-cut drill bit and all the other drill bits), then can realize the object of composite drill bit gauge.
(2) rotary-cut drill bit (well center)+PDC drill bit (well is peripheral): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, PDC drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit center is made up of rotary-cut drill bit, and well periphery is made up of PDC drill bit.Rotary-cut bit diameterbe less than composite drill bit diameter:.In drilling process, creeping into of well center is completed by rotary-cut Cutter, and creeping into of well periphery is completed by PDC Cutter.Performance characteristics: composite drill bit center break lithology can high, rate of penetration is high.
(3) rotary-cut drill bit (well center and well periphery)+PDC drill bit (well periphery+secondary wing): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, PDC drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit is based on rotary-cut drill bit structure, is trapped among the secondary wing of PDC Bit between rotary-cut bit cone outside well.In drilling process, creeping into of well center is completed by rotary-cut Cutter, and creeping into of well periphery is completed jointly by rotary-cut drill bit and PDC Cutter.Performance characteristics: as previously mentioned, peripheral rock breaking capacity reinforcement, gauge better effects if, drilling process stability increase, are more suitable for sidetracking, directional well operation:
(4) rotary-cut drill bit (well is peripheral)+two wing PDC drill bits (well center and well periphery): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, PDC drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit is based on the PDC drill bit structure of four wings, and well periphery replaces secondary wing by rotary-cut drill bit.In drilling process, the PDC cutting teeth crept into by being positioned on the operator wing of well center completes, and creeping into of well periphery is completed jointly by rotary-cut drill bit and PDC Cutter.Performance characteristics: as previously mentioned, improve efficiency of breaking rock and rate of penetration, minimizing PDC thermal friction phenomenon, make cutting teeth even wearing, improve bit life, composite drill bit is applicable to small size well simultaneously, and rotary-cut drill bit realizes gauge effect.
(5) rotary-cut drill bit (well is peripheral)+three wing PDC drill bits (well center and well periphery): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, PDC drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit is based on the PDC drill bit structure of six wings, and well periphery replaces secondary wing by rotary-cut drill bit.In drilling process, the PDC cutting teeth crept into by being positioned on the operator wing of well center completes, and creeping into of well periphery is completed jointly by rotary-cut drill bit and PDC Cutter.Performance characteristics: as previously mentioned, improve efficiency of breaking rock and rate of penetration, minimizing PDC thermal friction phenomenon, make cutting teeth even wearing, improve bit life, composite drill bit is applicable to slightly big size hole simultaneously, and rotary-cut drill bit realizes gauge effect.
(6) rotary-cut drill bit (well center)+PDC drill bit (well is peripheral)+rotary-cut drill bit (well is peripheral): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, PDC drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit center is made up of rotary-cut drill bit, and well periphery is made up of PDC and rotary-cut drill bit.The structure of well periphery, based on the PDC drill bit of four wings or six wings, replaces secondary wing by rotary-cut drill bit and forms.In drilling process, the rotary-cut Cutter crept into by being positioned at bit central of well center completes, and creeping into of well periphery is completed by PDC drill bit and the rotary-cut Cutter being positioned at periphery.Performance characteristics: composite drill bit is applicable to slightly big size hole, center break lithology can high, rate of penetration is high, gauge is effective.
(7) rotary-cut drill bit (well center)+rock bit (well is peripheral): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, rock bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit center is made up of rotary-cut drill bit, and well periphery is made up of conventional rock bit (gear wheel number >=1).In drilling process, creeping into of well center is completed by rotary-cut Cutter, and creeping into of well periphery is completed by conventional rock bit cutting teeth.Performance characteristics: composite drill bit is applicable to big size hole (as no-dig technique field etc.), center break lithology can high, rate of penetration is high.
(8) rotary-cut drill bit (well is peripheral)+rock bit (well center): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit, rock bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit center is made up of (gear wheel number >=1) conventional rock bit, and well periphery is made up of rotary-cut drill bit.In drilling process, creeping into of well center is completed by conventional rock bit cutting teeth, and creeping into of well periphery is completed by rotary-cut Cutter.Performance characteristics: composite drill bit is applicable to big size hole (as no-dig technique field etc.), and gauge is effective.
(9) rotary-cut drill bit (well center and well periphery)+rotary-cut drill bit (well is peripheral): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit and rotary-cut drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein composite drill bit is based on rotary-cut drill bit structure, is trapped among the peripheral rotary-cut drill bit of compound between rotary-cut bit cone outside well.In drilling process, creeping into of well center is completed by center rotary-cut Cutter, and creeping into of well periphery is completed jointly by center rotary-cut drill bit and peripheral rotary-cut Cutter.Performance characteristics: composite drill bit is applicable to slightly small size well, center break lithology can high, rate of penetration is high, gauge is effective.
(10) rotary-cut drill bit (well center)+rotary-cut drill bit (well is peripheral): this architectural feature is: described composite drill bit is made up of rotary-cut drill bit and rotary-cut drill bit, at least comprises a connection be made up of the upper roller axle neck of rotary-cut bit cone (2) and main body (1).Wherein bit central is made up of rotary-cut drill bit, and well periphery is also made up of rotary-cut drill bit.In drilling process, center and the creeping into of well periphery of well complete by rotary-cut Cutter.Performance characteristics: composite drill bit is applicable to slightly big size hole, center break lithology can high, rate of penetration is high, gauge is effective.
Beneficial effect of the present invention: the rotary-cut Cutter in composite drill bit of the present invention is with breaking rock by rotary cutting, and center efficiency of breaking rock is high, and rate of penetration is high, there is better dynamic performance, even wearing, bearing working improvement of terms, drilling life of bit is long, and gauge is effective; Composite drill bit comprises rotary-cut drill bit and PDC drill bit compound, rotary-cut drill bit and rock bit compound, rotary-cut drill bit and rotary-cut drill bit compound, and different composite constructions can realize center and break the effect that lithology energy is high, rate of penetration is high, gauge is effective.
Accompanying drawing explanation
Accompanying drawing of the present invention is described as follows:
Fig. 1 is the structural representation of rotary-cut drill bit and PDC drill bit compound in the present invention, comprises main body (1), rotary-cut bit cone (2), rotary-cut Cutter (3), PDC drill bit wing (4), PDC cutting teeth (5), oil storage bag (6), nozzle (7).Drill main body (1) comprises gear wheel axle journal, wiper block, high-pressure slurry passage and thread.Wherein bit central is made up of rotary-cut drill bit, and well periphery is made up of PDC drill bit.In drilling process, creeping into of well center is completed by rotary-cut Cutter, and creeping into of well periphery is completed by PDC Cutter.
Fig. 2 is the rotary-cut drill bit structure schematic diagram in composite drill bit of the present invention, comprises drill main body (1), rotary-cut bit cone (2), rotary-cut Cutter (3).Drill main body (1) comprises gear wheel axle journal, wiper block, high-pressure slurry passage and thread.Gear wheel (2) and the axle journal in main body (1) adopt the bearing and hermetically-sealed construction that tricone bit is conventional.The large end of gear wheel (2) arranges multi-turn cutting teeth to small end.
Fig. 3 is cutting principle and the main design parameters of rotary-cut drill bit in composite drill bit of the present invention: wheel body angle, axle journal deviant, rotary-cut bit diameterrelation schematic diagram;
Fig. 4 be composite drill bit of the present invention by rotary-cut drill bit and PDC drill bit compound, wherein composite drill bit center is made up of rotary-cut drill bit, well periphery is made up of PDC drill bit.When rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when PDC drill bit is six wing structure, the hat roof construction schematic diagram of composite drill bit;
Fig. 5 is the gear wheel gear ring perspective view of the composite drill bit that Fig. 4 is corresponding;
Fig. 6 be composite drill bit of the present invention by rotary-cut drill bit and PDC drill bit compound, wherein composite drill bit is based on rotary-cut drill bit structure, to be trapped among between rotary-cut bit cone the secondary wing of PDC Bit outside well.When rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when PDC drill bit is two wing structure, the gear wheel gear ring perspective view of composite drill bit;
Fig. 7 be composite drill bit of the present invention by rotary-cut drill bit and PDC drill bit compound, wherein composite drill bit is based on the PDC drill bit of four blade wing structure, well periphery replaces secondary wing by rotary-cut drill bit.When rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and do not cut heart portion, and when PDC drill bit is two wing structure, the gear wheel gear ring perspective view of composite drill bit;
Fig. 8 be composite drill bit of the present invention by rotary-cut drill bit and PDC drill bit compound, wherein composite drill bit is based on the PDC drill bit structure of six wings, well periphery replaces secondary wing by rotary-cut drill bit.When rotary-cut bit cone number is 3, wheel body angle, axle journal deviant, and do not cut heart portion, and when PDC drill bit is three wing structure, the gear wheel gear ring perspective view of composite drill bit;
Fig. 9 is composite drill bit of the present invention by rotary-cut drill bit (bit central), PDC drill bit (well is peripheral), rotary-cut drill bit (well is peripheral) compound, and wherein composite drill bit center is made up of rotary-cut drill bit, and well periphery is made up of PDC and rotary-cut drill bit.The structure of well periphery, based on the PDC drill bit of four wings or six wings, replaces secondary wing by rotary-cut drill bit and forms.When bit central rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when well peripheral rotary-cut bit cone number is 3, wheel body angle, axle journal deviant, and do not cut heart portion, and when the peripheral PDC drill bit of well is three wing structure, the gear wheel gear ring perspective view of composite drill bit;
Figure 10 be composite drill bit of the present invention by rotary-cut drill bit and rock bit compound, wherein composite drill bit center is made up of rotary-cut drill bit, well periphery is made up of conventional rock bit (gear wheel number >=1).When bit central rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when the peripheral rock bit of well is tricone bit, the gear wheel gear ring perspective view of composite drill bit;
Figure 11 be composite drill bit of the present invention by rotary-cut drill bit and rock bit compound, wherein composite drill bit center is made up of (gear wheel number >=1) conventional rock bit, well periphery is made up of rotary-cut drill bit.When bit central rock bit is tricone bit, well peripheral rotary-cut bit cone number is 3, wheel body angle, axle journal deviant, and one is cut heart portion, one when not cutting heart portion, the gear wheel gear ring perspective view of composite drill bit;
Figure 12 be composite drill bit of the present invention by rotary-cut drill bit and rotary-cut drill bit compound, wherein composite drill bit is based on rotary-cut drill bit structure, to be trapped among between rotary-cut bit cone the peripheral rotary-cut drill bit of compound outside well.When bit central rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when well peripheral rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and when not cutting heart portion, the gear wheel gear ring perspective view of composite drill bit;
Figure 13 be composite drill bit of the present invention by rotary-cut drill bit and rotary-cut drill bit compound, wherein bit central is made up of rotary-cut drill bit, and well periphery is also made up of rotary-cut drill bit.When bit central rotary-cut bit cone number is 2, wheel body angle, axle journal deviant, and one is cut heart portion, does not cut heart portion for one, and when well peripheral rotary-cut bit cone number is 3, wheel body angle, axle journal deviant, and when not cutting heart portion, the gear wheel gear ring perspective view of composite drill bit;
Figure 14 is the rotary-cut bit cone number in composite drill bit of the present invention is 2, bit diameter, wheel body angle, axle journal deviantthe test drill bit shaft bottom profile that carries out simulated test and get out;
Figure 15 is tricone bit diameterthe shaft bottom profile got out;
Figure 16 is single-cone rotary drill bit diameterthe shaft bottom profile got out;
Figure 17 is PDC bit diameterthe shaft bottom profile got out.