CN110924872A - Drill bit for reverse circulation drilling - Google Patents
Drill bit for reverse circulation drilling Download PDFInfo
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- CN110924872A CN110924872A CN201811103302.6A CN201811103302A CN110924872A CN 110924872 A CN110924872 A CN 110924872A CN 201811103302 A CN201811103302 A CN 201811103302A CN 110924872 A CN110924872 A CN 110924872A
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- blade
- drill bit
- reverse circulation
- cutting
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- 238000005553 drilling Methods 0.000 title claims abstract description 138
- 230000002441 reversible effect Effects 0.000 title claims abstract description 67
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 189
- 238000005520 cutting process Methods 0.000 claims abstract description 105
- 239000011435 rock Substances 0.000 claims abstract description 67
- 230000036346 tooth eruption Effects 0.000 claims abstract description 29
- 239000011241 protective layer Substances 0.000 claims description 6
- 238000000034 method Methods 0.000 abstract description 34
- 239000002002 slurry Substances 0.000 description 10
- 238000007599 discharging Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000009826 distribution Methods 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 230000003467 diminishing effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000005219 brazing Methods 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 239000010410 layer Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002905 metal composite material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000005086 pumping Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
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Classifications
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/60—Drill bits characterised by conduits or nozzles for drilling fluids
- E21B10/602—Drill bits characterised by conduits or nozzles for drilling fluids the bit being a rotary drag type bit with blades
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
- E21B10/43—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
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- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Mining & Mineral Resources (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Fluid Mechanics (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Earth Drilling (AREA)
Abstract
The invention provides a drill bit for reverse circulation drilling, comprising: the drill bit comprises a drill bit main body, a drill bit body and a drill bit, wherein the drill bit main body comprises a connecting section and a cutting section which are arranged along the axial direction; the connecting section is internally provided with a water channel arranged along the axial direction of the connecting section; the cutting section is provided with at least two blades, the blades are provided with cutting teeth, the cutting section is provided with at least two water holes, the first end of the water channel is communicated with the inner cavity of the drill rod, and the second end of the water channel is communicated with the water holes, so that mud and rock debris generated in drilling can enter the water channel from the water holes; the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 3/10 to 6/5; the cutting section is also provided with a diversion trench, one end of the diversion trench extends to the edge of the cutting section, and the other end of the diversion trench is communicated with the water hole. In the reverse circulation drilling process, the rock debris generated by cutting the cutting teeth on the blades can be effectively discharged into the water hole with the size range, and the situation that the water hole is blocked by the rock debris is avoided.
Description
Technical Field
The invention relates to the technical field of oil and gas field exploitation, in particular to a drill bit for reverse circulation drilling.
Background
The prior drilling mode mainly comprises a forward circulation drilling mode and a reverse circulation drilling mode, wherein a drill rod is required to be used in the drilling process, a drill bit is arranged at one end of the drill rod, in the forward circulation drilling process, mud is pumped into an inner cavity of the drill rod from a mud pool by a mud pump, is conveyed to the drill bit from the inner cavity of the drill rod, is continuously conveyed into the drilling well through a water hole of the drill bit, and is discharged from an annular space between a well wall and the drill rod, and meanwhile, rock debris generated in the drilling process is discharged to the ground along with the mud from the annular space; the circulation mode of the mud for reverse circulation drilling is just the reverse, the mud is conveyed into the drilling well from the annular space by a mud pump, and then compressed air or the mud pump is used for sucking the mud and rock debris into the inner cavity of the drill rod through the water hole of the drill bit and then pumping the mud and the rock debris out of the inner cavity of the drill rod to the ground.
The drill bit for drilling in the positive circulation has very strict requirements on the relative positions of the water holes and the blades, and the general design is that each blade corresponds to one water hole, so that the effective diameter of the water holes of the drill bit for drilling in the positive circulation on the limited drill bit end face is smaller. However, in the reverse circulation drilling process, mud and rock debris generated in the drilling process are sucked into the drill rod through the water hole on the drill bit, and the water hole on the drill bit is small, so that the water hole is easily blocked by the mud and the rock debris in the reverse circulation drilling process, and the situations of low drilling efficiency and drilling failure occur.
Therefore, designing a drill bit specially adapted for reverse circulation drilling becomes an urgent problem to be solved.
Disclosure of Invention
The invention provides a drill bit for reverse circulation drilling, which aims to solve the problems that in the prior art, mud and rock debris are easy to block water holes to cause low drilling efficiency and drilling failure in the process of reverse circulation drilling by using a drill bit for forward circulation drilling.
To achieve the above object, the present invention provides a drill bit for reverse circulation drilling, comprising: a bit body including a connecting section and a cutting section disposed axially;
the connecting section is internally provided with a water channel arranged along the axial direction of the connecting section;
the cutting section is provided with at least two blades, the blades are provided with cutting teeth, the cutting section is provided with at least two water holes, the first end of the water channel is communicated with the inner cavity of the drill rod, and the second end of the water channel is communicated with the water holes, so that mud and rock debris generated in drilling can enter the water channel from the water holes;
the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 3/10 to 6/5;
the cutting section is further provided with a flow guide groove, one end of the flow guide groove extends to the edge of the cutting section, and the other end of the flow guide groove is communicated with the water hole.
Optionally, the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 1/2 to 1/1.
Optionally, the diversion trench is disposed near a sidewall of the blade.
Optionally, the number of the flow guide grooves is at least two, and one blade corresponds to at least one flow guide groove.
Optionally, at least one water hole is arranged on the side of each blade.
Optionally, the blades include a first blade and a second blade, the length of the first blade is greater than that of the second blade, a first end of the first blade extends to the middle of the cutting section, and a second end of the first blade is located at the edge of the cutting section.
Optionally, the first blade is recessed from an edge of the cutting segment toward a middle.
Optionally, the first end of the second blade faces the water hole, and the second end of the second blade is located at the edge of the cutting section.
Optionally, the inner wall and the opening of each water hole are provided with a protective layer.
Optionally, the cross-sectional shape of the water hole is circular.
The invention provides a drill bit for reverse circulation drilling, which comprises a drill bit main body, wherein the drill bit main body comprises a connecting section and a cutting section which are arranged along the axial direction; the connecting section is internally provided with a water channel arranged along the axial direction of the connecting section; the cutting section is provided with at least two blades, the blades are provided with cutting teeth, the cutting section is provided with at least two water holes, the first end of the water channel is communicated with the inner cavity of the drill rod, and the second end of the water channel is communicated with the water holes, so that mud and rock debris generated in drilling can enter the water channel from the water holes; the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 3/10 to 6/5; the cutting section is also provided with a diversion trench, one end of the diversion trench extends to the edge of the cutting section, and the other end of the diversion trench is communicated with the water hole; the drill bit has the advantages that at least two blades with cutting teeth are arranged on the cutting section of the drill bit main body, normal drilling of reverse circulation drilling is guaranteed, at least two water holes are arranged on the cutting section, the ratio range of the cross section area of the water holes to the cross section area of a water channel is limited to 3/10-6/5, and meanwhile, the guide grooves are formed in the lateral sides of the blades, so that in the reverse circulation drilling process, mud required by drilling and rock debris generated by cutting of the cutting teeth on the blades can be effectively discharged into the water holes in the size range and finally discharged to the ground through the water channel in the connecting section.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of the overall structure of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention;
FIG. 2 is a schematic diagram of a cutting segment of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention;
FIG. 3 is a schematic cross-sectional view of a first embodiment of a drill bit for reverse circulation drilling according to the present invention;
FIG. 4 is a top view of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention.
Description of reference numerals:
1-a drill bit body;
2-a connecting section;
3, cutting;
4-water channel;
5, a blade;
501-first blade;
502 — a second blade;
6, cutting teeth;
7-water eye;
8-guiding gutter.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The forward circulation drilling and the reverse circulation drilling are two main drilling modes at present, and the two drilling modes bring different advantages and disadvantages due to different working principles; the forward circulation drilling is to take the rock debris out of the ground by means of natural circulation of mud, so that the circulation capacity and the slag discharge capacity are weak, but the process is simple, and the forward circulation drilling tool is cheap, while the reverse circulation drilling is to convey the mud into the drilling well from an annular space by using a mud pump, then use compressed air or the mud pump, suck the mud and the rock debris into an inner cavity of a drill rod through a water hole of a drill bit, and then pump the mud and the rock debris out of the inner cavity of the drill rod to the ground, so that the circulation capacity and the slag discharge capacity are strong in the whole process, and therefore, the reverse circulation drilling is a commonly used drilling mode in the drilling operation at present. The drill bit for forward circulation drilling is also used for reverse circulation drilling because the cost of the drill bit is low, but in the reverse circulation drilling process, mud and rock debris generated in the drilling process are sucked into a drill rod through a water hole on the drill bit, and because the water hole on the drill bit is small, the mud and the rock debris are easy to block the water hole in the reverse circulation drilling process, so that the drilling efficiency is low and the drilling failure occurs.
Fig. 1 is a schematic overall structure diagram of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention, fig. 2 is a schematic structural diagram of a cutting segment of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention, fig. 3 is a schematic sectional structure diagram of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention, and fig. 4 is a top view of a first embodiment of a drill bit for reverse circulation drilling provided by the present invention. Referring to fig. 1 to 4, a drill bit for reverse circulation drilling comprises a drill bit body 1, wherein the drill bit body 1 comprises a connecting section 2 and a cutting section 3 which are arranged along an axial direction; a water channel 4 arranged along the axial direction of the connecting section 2 is arranged in the connecting section 2; the cutting section 3 is provided with at least two blades 5, the blades 5 are provided with cutting teeth 6, the cutting section 3 is provided with at least two water holes 7, a first end of the water channel 4 is communicated with an inner cavity of a drill rod, and a second end of the water channel 4 is communicated with the water holes 7, so that mud and rock debris generated in drilling enter the water channel 4 from the water holes 7; the ratio of the cross-sectional area of the water hole 7 to the cross-sectional area of the water channel 4 ranges from 3/10 to 6/5; the cutting section 3 is further provided with a flow guide groove 8, one end of the flow guide groove 8 extends to the edge of the cutting section 3, and the other end of the flow guide groove 8 is communicated with the water hole 7.
The embodiment of the invention is connected with a drill rod through a connecting section 2 on a drill bit main body 1 and further connected with a drilling power output device, a cutting section 3 on the drill bit main body 1 is used for cutting in the drilling process, and the drilling power output device drives the drill rod to rotate so as to drive the connecting section 2 and the cutting section 3 on the drill bit main body 1 to rotate, so that the drilling work is completed.
Specifically, the connecting section 2 and the cutting section 3 can be integrally arranged, and the integrated arrangement mode not only enables the water channel 4 on the connecting section 2 and the water hole 7 on the cutting section 3 to be more smoothly communicated, and realizes that mud required by drilling and rock debris generated in the drilling process are easier to be discharged to the ground through the water hole 7 and the water channel 4, so that the situation that the rock debris is blocked in the drill bit main body 1 is avoided, but also the assembly of parts can be reduced, and the structure of the drill bit is simplified; the connecting section 2 and the cutting section 3 can also be detachably connected, for example, in a threaded connection mode, so that the connecting section 2 and the cutting section 3 can be freely detached in the process of overhauling the internal channel of the drill bit main body 1, and the practicability of the drill bit is further improved.
The connecting section 2 and the cutting section 3 of the drill bit main body 1 are made of alloy with certain hardness, for example, alloy steel with certain hardness is adopted, so that the drill bit is easier to drill, the drilling efficiency is improved, the durability of the drill bit is improved, the service life is prolonged, the frequency of replacing the drill bit is reduced, and the operating cost of reverse circulation drilling is further reduced.
The shape of the connecting section 2 on the drill bit main body 1 can be cylindrical, conical, prismatic and the like, as long as one end of the connecting section 2 can be in matched connection with a drill rod, and the other end of the connecting section 2 is in matched connection with the cutting section 3, preferably, the connecting section 2 is integrally cylindrical, so that in the drilling process, as the outer wall of the connecting section 2 is smooth, the well wall in contact with the connecting section is not easy to damage, the secondary plugging work is avoided, the drilling efficiency is improved, and the performance of the drill bit is optimized; one end of the connecting section 2 can be configured to be connected with external equipment quickly, for example, the cross-sectional area of the end of the connecting section 2 in a certain length is smaller than that of the main body of the connecting section 2; in addition, the connection mode of the connection section 2 and the drill rod is not limited, for example, an external thread can be arranged at one end of the connection section 2, and an internal thread is arranged at one end of the drill rod, so that the connection section 2 and the drill rod are connected in a threaded fit mode, and the drill bit is convenient to detach and install.
The cutting section 3 of the drill bit main body 1 is provided with at least two blades 5, and the at least two blades 5 can be arranged on the cutting section 3 at intervals, so that at least one water hole 7 is arranged on the side of each blade 5, and rock debris generated by the cutting teeth 6 on each blade 5 in the cutting process can enter the water hole 7 beside the blade 5 to the maximum extent, so that the rock debris is prevented from moving from one side of the blade 5 to the other side to cause secondary drilling of the rock debris by the cutting teeth 6, the consumption of the cutting teeth 6 on the blades 5 is further saved, and the drilling efficiency is improved; the cutting teeth 6 arranged on the blades 5 are used for drilling rock; under the condition that the size of the water holes 7 meets the requirement of entering rock debris, two water holes 7 can be arranged on the side of the blade 5, so that the rock debris discharging effect is more remarkable; in addition, the at least two blades 5 are arranged on the cutting section 3 at intervals, so that the uniformity of flow distribution of the blades 5 on the whole cutting section 3 can be further ensured, the cutting teeth 6 on the blades 5 can realize full coverage of the bottom of a well in the drilling process, and the whole drilling efficiency and the drilling performance of the drill bit are improved.
The fixing mode between the blade 5 and the cutting tooth 6 on the cutting section 3 is not limited, the blade 5 and the cutting tooth 6 can be integrally arranged, for example, the cutting tooth 6 can be integrally fixed on the blade 5 in a brazing mode, and also can be detachably arranged, for example, a plurality of connecting grooves for placing the cutting tooth 6 are preset on the blade 5 on the cutting section 3, and the cutting tooth 6 is stably clamped in the corresponding connecting groove, so that the disassembly is convenient; preferably, the cutting teeth 6 on the blades 5 are PDC cutting teeth, namely polycrystalline diamond compact cutting teeth, and the PDC cutting teeth can be manufactured by artificial polycrystalline diamond compacts, so that the hardness of the cutting teeth 6 is effectively guaranteed, and the drilling efficiency and the durability of a drill bit are further improved.
Optionally, the number of the blades 5 can be set to 3, as long as the size of the water hole 7 is ensured to meet the requirement that the ratio of the cross-sectional area of the water hole 7 to the cross-sectional area of the water channel 4 is 3/10-6/5, so as to ensure the whole drilling efficiency, and the number of the blades 5 and the number of the cutting teeth 6 on the blades 5 can be specifically designed according to the size of the cutting section 3 and the characteristics of the applicable rock stratum; the blades 5 can be arranged in a rotating arc-shaped structure according to the rotating direction of the drill bit body 1 when the drill bit body rotates under the driving of power output equipment, parameters such as the specific rotating arc-shaped curved surface radius of the blades 5 can be obtained through simulation according to various parameters during drilling, so that the motion trend of the drill bit in the whole drilling process is matched, the cutting teeth 6 on the blades 5 are cut to the maximum degree, and the applicability of the drill bit is guaranteed.
The water channel 4 is arranged in the connecting section 2 of the drill bit main body 1 along the axial direction and is mainly used for discharging slurry and water used in the reverse circulation drilling process into the water channel 4 through the water hole 7 and discharging the slurry and the water to the ground through the drill rod, and rock debris generated in the drilling process can be brought out together while the slurry and the water are discharged, so that the first end of the water channel 4 is communicated with the inner cavity of the drill rod, the second end of the water channel 4 is communicated with the water hole 7 formed in the cutting section 3, the drill bit and the drill rod form an internal channel, and the slurry, the rock debris and the like in the reverse circulation drilling process are conveyed;
follow in the linkage segment 2 the shape of the cross section of the water course 4 of the axial setting of linkage segment 2 can be arbitrary shape, for example circular, polygon etc., and the size of the cross section of water course 4 can keep unanimous along the axial of water course 4, also can be inconsistent, for example along the axial of water course 4, the cross section size of water course 4 is from last to diminishing gradually down or diminishing gradually, also can irregularly change, only can be with the detritus that gets into through the water hole 7 can follow this water course 4 discharge can, preferably, the size of the cross section of water course 4 can keep unanimous along the axial of water course 4, such setting has guaranteed that the detritus can discharge in water course 4 more smoothly and fast, avoid the inside jam of water course 4 and influence the smooth discharge of detritus, the effectual smooth progress of whole reverse circulation drilling of having guaranteed.
In the process of forward circulation drilling, the water holes on the drill bit only discharge mud used in the drilling process into the well, and then discharge the mud and rock debris generated in the drilling process to the ground through the annular space, namely the gap between the drill bit and the well wall, so that the cross section size of the water holes only needs to be discharged, and the requirement of the forward circulation drilling on the flow distribution of the blades is strict, namely the relative positions of the water holes and the blades need to ensure that the flow distribution of each blade is optimal, therefore, the drill bit for forward circulation drilling generally corresponds to one water hole as much as possible, the size of the water hole cannot meet the requirement of reverse circulation drilling, and the reverse circulation drilling process requires that the water holes 7 can smoothly enter the water channel 4 through the rock debris, so the ratio range of the cross section area of the water holes 7 to the cross section area of the water channel 4 needs to be controlled within 3/10-6/5, namely the cross section area of the water hole 7 is equal to 30-120 percent of the cross section area of the water channel 4, wherein the cross-sectional area of the port 7 is set to 30% of the cross-sectional area of the water course 4, which is designed according to the maximum size of the debris cut by the cutter 6 in the reverse circulation drilling, i.e. 30% is the minimum value capable of discharging the rock debris through the port 7 into the channel 4, and the cross-sectional area of the port 7 is set to 120% of the cross-sectional area of the channel 4, which is the maximum size capable of better discharging all the rock debris smoothly into the port 7, with an upper limit meaning that the cross-sectional area of the port 7 cannot be too large, i.e. not more than 120% of the cross-sectional area of the water channel 4, an excessively large port 7 not only limits the number and size of the blades, further influencing the whole rock drilling process, and the overlarge water hole is easily damaged by mud or rock debris, so that the whole drill bit cannot be used; therefore, the water hole within the size range can effectively discharge rock debris generated during drilling of the reverse circulation PDC drill bit, the blocking situation is avoided, the rock debris enters the water channel 4 of the connecting section 2 through the reverse circulation of the water hole 7, and finally the rock debris is discharged out of the well to complete the reverse circulation drilling work, and it needs to be emphasized that the cross section area of the water hole 7 needs to be as large as possible within the range so as to ensure that the rock debris can be discharged from the water channel 4 of the water hole 7, and then the reverse circulation drilling work is carried out.
In addition, there is a special PDC drill bit for stopping leakage at present, this drill bit is used in the rock of the drilled well, convey the filling material to the not drilled well wall through the big water hole in this drill bit centre, play the role of stopping leakage, at the same time, the cutting tooth on the blade of the water hole one week is used for enlarging the well bore, but the cross sectional area of the water hole 7 on the drill bit of this invention is close to 120% or equal to 120% of the cross sectional area of the water course 4, make the drill bit for reverse circulation well drilling of this invention can also be used for the job of stopping leakage of the shaping well bore, and then make the function of the drill bit for reverse circulation well drilling of this invention more comprehensive.
The cross section of the water eye 7 can be a circular opening or other geometric shapes, when the cross section area of the water eye 7 is consistent from the section of the water eye 7 contacted with the second end of the water channel 4 to the opening section of the water eye 7 and the cross section areas of the water channels along the axial direction are consistent, the ratio range of the cross section area of the water eye to the cross section area of the water channel is 3/10-6/5, and the cross section area of the water eye and the cross section area of the water channel can refer to the cross section areas of any positions; if the cross-sectional area of the water eye 7 is not consistent from the contact section of the water eye 7 and the second end of the water channel 4 to the opening section of the water eye 7 and the cross-sectional areas of the water channel 4 along the axial direction are consistent, the ratio of the cross-sectional area of the water eye 7 to the cross-sectional area of the water channel 4 is in the range of 3/10-6/5, and the cross-sectional area of the water eye 7 refers to the cross-sectional area of the opening of the water eye 7, so that rock debris can better enter the water eye 7 and the water channel 4 from the opening of the water eye 7; if the cross-sectional area of the water hole 7 is not consistent from the contact section of the water hole 7 and the second end of the water channel 4 to the opening section of the water hole 7 and the cross-sectional area of the water channel 4 along the axial direction is not consistent, the ratio of the cross-sectional area of the water hole 7 to the cross-sectional area of the water channel 4 is in the range of 3/10-6/5, the cross-sectional area of the water hole 7 refers to the cross-sectional area at the opening of the water hole 7, and the cross-sectional area of the water channel 4 refers to the maximum cross-sectional area of the water channel 4 along the axial direction of the water channel.
Water course 4 in linkage segment 2 can open and locate 2 central axis positions of linkage segment, also can set up at the center pin side, and each water hole 7 on the cutting segment 3 is kept away from open-ended one end and is all converged to the second end of this water course 4, and the position of the contact of the second end of the water hole 7 of seting up on the cutting segment 3 and water course 4 can set up the reinforcement part to the position of the reposition of redundant personnel that makes water hole 7 and water course 4 is more firm, avoids influencing the smooth and easy intercommunication between water hole 7 and the water course 4.
In order to effectively discharge rock debris generated by cutting of the cutting teeth 6 on the blades 5 into the water holes 7 in the reverse circulation drilling process, a plurality of guide grooves 8 are formed in the cutting section 3, one ends of the guide grooves 8 extend to the edge of the cutting section 3, and the other ends of the guide grooves 8 are communicated with the water holes 7 to play a role in drainage; wherein, extend to the edge of cutting section 3 with the one end of guiding gutter 8 to make it can be fine cover whole cutting section 3, guarantee the inflow guiding gutter 8 of the detritus bigger degree on wing 5, also can make mud and water in the annular space also flow into guiding gutter 8 in addition, and the other end of guiding gutter 8 communicates with water hole 7 in order to make mud and water and detritus discharge into water hole 7 smoothly together.
In addition, due to the arrangement of the diversion trench 8, rock debris cut by the cutting teeth 6 on the blades 5 can fall into the diversion trench 8 together with drilling water, and the water flowing through the diversion trench 8 can dissipate heat of the blades 5, so that the blades 5 can be at a proper working temperature, and the normal work of the blades 5 cannot be influenced due to overhigh temperature.
The diversion trench 8 can be in various forms on the cutting section 3, for example, the diversion trench 8 can be a trench body fixed on the cutting section 3, but in order to make the rock debris enter the trench body from the blade 5 more easily, preferably, the height of the trench body is lower than the horizontal height of the cutting teeth 6 on the blade 5, and the trench body can be fixed on the cutting section 3 in a welding manner or can be fixed by screws and the like, so that the trench body is convenient to disassemble; the diversion trench 8 can also be a groove formed in the cutting section 3 and is integrally arranged with the cutting section 3, the diversion trench 8 in the form of the groove enables the whole drill bit to be simpler in structure, rock debris, slurry, water and the like can be collected more easily and discharged into the water hole 7, and the manufacturing cost of the drill bit is further reduced.
The shape of the diversion trench 8 can be various, for example, the diversion trench can be consistent with the trend of the blade 5, and can also be arranged in an S shape along the axial direction, as long as one end of the diversion trench 8 extends to the edge of the cutting section 3, and the other end is communicated with the water hole 7; the radial width and depth of the diversion trench 8 are not limited, as long as rock debris, slurry and the like can be ensured to enter the water hole 7 under the drainage effect of the diversion trench 8.
Considering the cooperation between the water channel 4 in the connecting section 2 and the water holes 7 on the cutting section 3, that is, the water and rock debris entering the water holes 7 can be smoothly and rapidly discharged through the water channel 4, and considering the size of the rock debris to be discharged when the water holes 7 are used for reverse circulation drilling, preferably, the ratio of the cross-sectional area of the water holes 7 to the cross-sectional area of the water channel 4 is in the range of 1/2-1/1, that is, the cross-sectional area of the water holes 7 is preferably equal to 50% -100% of the cross-sectional area of the water channel, wherein the cross-sectional area of the water holes 7 also has several better values, for example, the cross-sectional area of the water holes 7 is equal to the cross-sectional area of the water channel 4, or equal to 80% of the cross-sectional area of the water channel 4, and the sizes of the water holes 7 are all capable of better discharging the slurry and the rock debris into the water channel 4 of the connecting section 2 through the water holes, the specific size of the water hole can be specifically set according to the size of the drill bit body 1 and the characteristics of the rock stratum to which the drill bit is applied.
Optionally, the diversion trench 8 is disposed near the side wall of the blade 5, so that the rock debris cut by the blade 5 can fall into the diversion trench 8 together with the drilling water to a greater extent, and then flow into the water hole 7.
Optionally, the number of the diversion trenches 8 is at least two, that is, the number of the diversion trenches is the same as that of the blades 5, and is equivalent to that one side of each blade 5 is provided with one diversion trench 8, preferably, two side portions of each blade 5 are provided with one diversion trench 8, and one side of each blade 5 is provided with a plurality of diversion trenches 8, so as to ensure that rock debris cut by the blades 5 can completely and directly fall into the diversion trenches 8 and is discharged into the water holes 7 together with water, slurry and the like.
Optionally, at least one water hole 7 is formed in the side portion of each blade 5, that is, at least two water holes 7 separate at least two blades 5, so that one water hole 7 is formed in one side of each blade 5, and rock debris cut by the cutting teeth 6 on each blade 5 can rapidly enter the water hole 7 during reverse circulation drilling.
In order to provide enough space on the cutting segment 3 of the embodiment of the invention with a large enough water hole 7 and at the same time enable faster drilling of rock in the reverse circulation drilling process, the blades 5 on the cutting segment 3 comprise a first blade 501 and a second blade 502, the length of the first blade 501 is greater than that of the second blade 502, the first end of the first blade 501 extends to the middle of the cutting segment 3, and the second end of the first blade 501 is located at the edge of the cutting segment 3.
Specifically, the number of the first blades 501 on the cutting section 3 is at least two, the first ends of the first blades 501 extend to the middle of the cutting section 3, and the second ends are located at the edge of the cutting section 3, so that the arranged first blades 501 can enable the cutting teeth 6 to realize full coverage of the bottom of the well during drilling, and ensure normal formation drilling;
the arrangement of the water holes 7 needs to be based on the principle that the side portions of the first blades 501 are correspondingly provided with one water hole 7, and preferably, the first blades 501 are higher than the surface of the cutting section 3, and the water holes 7 are located on the surface of the cutting section 3, that is, the first blades 501 can also be of a structure with gradually changed height, and the first blades 501 are recessed from the edge of the cutting section 3 to the middle portion, in other words, the height of the body of the first blades 501 at the edge position of the cutting section 3 is higher than the height of the body of the first blades 501 at the center position of the cutting section 3, so that water and rock debris can be directly discharged from the water holes 7, the rock debris is prevented from going from one side to the other side of the first blades 501, further, secondary drilling of the rock debris is avoided, consumption of the cutting teeth 6 on the first blades 501 is saved, and drilling efficiency is improved.
The number of the second blades 502 may be multiple, and the second blades 502 are arranged on the cutting segment 3 at intervals to ensure the arrangement space of the diversion trench 8, a first end of the second blade 502 faces and is close to the water hole 7, and a second end of the second blade 502 is located at the edge of the cutting segment 3; the second blade 502 is mainly used for the expansion of the well wall in the reverse circulation drilling process, so that the second end of the second blade 502 needs to be positioned at the edge of the cutting section 3, and the first end faces and is close to the water hole 7, so that only one water hole 7 is needed around the second blade 502, and the rock debris cut by the cutting teeth on the second blade 502 can be rapidly discharged into the water hole 7.
The second blades 502 and the first blades 501 are arranged in a matching manner, and the specific number of the first blades 501 and the second blades 502 is determined according to the size and the number of the water holes 7 formed in the cutting section 3 and the rock formation characteristics.
Specifically, the structure of the second blade 502 may be the same as that of the first blade 501, and the second blade 502 is only shorter than the first blade 501, so as to ensure that there is enough space for the size of the water hole 7 to be large enough; in addition, the arrangement position of the second blades 502 can be located in the vacant space of the first blades 501 dividing the first end of the cutting section 3, that is, one or more second blades 502 are arranged between two adjacent first blades 501, so that the central position of the cutting section 3 of the drill bit body 1 can have more sufficient space to open the water hole size meeting the reverse circulation drilling requirement; one end of the second blade 502 needs to be disposed at the edge of the first end of the cutting segment 3, and it should be emphasized that the other end of the second blade 502 needs to be directed to and close to the water hole 7, so that the water hole 7 can rapidly discharge the rock debris cut by the second blade 502.
Optionally, the number of the diversion trenches 8 is at least equal to the sum of the numbers of the first blade 501 and the second blade 502, that is, at least one diversion trench 8 is arranged on each of the first blade 501 and the second blade 502; each guiding groove 8 is correspondingly disposed along a sidewall of the first blade 501 or a sidewall of the second blade 502.
The plurality of flow guide grooves 8 may be divided into a plurality of flow guide groups, preferably, the number of the flow guide groups is equal to the number of the water holes 7, wherein each flow guide group corresponds to one water hole 7, and the flow guide grooves 8 in one flow guide group are all converged to the corresponding water holes 7.
Through the arrangement of the position of the water hole 7 and the arrangement of the positions of the second blade 502 and the water hole 7, rock debris can rapidly flow into the water hole 7 under the driving of water and the diversion of the diversion trench 8, and then rapidly enter the water channel 4 of the connecting section 2, so that the working efficiency of the drill bit for reverse circulation drilling is effectively improved.
Optionally, the inner wall and the opening of each water hole 7 are provided with a protective layer.
Specifically, since the drill bit for reverse circulation drilling of the present invention has a large amount of mixture of rock debris and water flowing through the port 7 during operation, in order to prevent the port 7 from being damaged by the rock debris, a protective layer is provided on the inner wall and the opening of the port 7 for improving the impact resistance and corrosion resistance of the port 7, wherein the protective layer may be a coated erosion-resistant coating or a metal composite layer; the water hole 7 provided with the protective layer effectively prevents rock debris, slurry and the like which cannot enter the water channel 4 more smoothly due to the damage of the water hole 7, further improves the drilling efficiency of the drill bit, prolongs the service life and saves the manufacturing cost to the maximum extent.
The cross section of the water hole 7 is round or other geometric shapes, preferably, the cross section of the water hole 7 is designed to be round, so that rock debris, slurry and the like can be discharged into the water channel 4 through the round water hole 7 more conveniently, and the whole reverse circulation drilling process is smoother.
The embodiment of the invention provides a drill bit for reverse circulation drilling, which comprises a drill bit main body, wherein the drill bit main body comprises a connecting section and a cutting section which are arranged along the axial direction; the connecting section is internally provided with a water channel arranged along the axial direction of the connecting section; the cutting section is provided with at least two blades, the blades are provided with cutting teeth, the cutting section is provided with at least two water holes, the first end of the water channel is communicated with the inner cavity of the drill rod, and the second end of the water channel is communicated with the water holes, so that mud and rock debris generated in drilling can enter the water channel from the water holes; the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 3/10 to 6/5; still be provided with the guiding gutter on the cutting section, the one end of guiding gutter extends to the edge of cutting section, the other end and the hydrophthalmia intercommunication of guiding gutter, through set up two at least hydrophthalmia on the cutting section, and the ratio scope of the cross sectional area of hydrophthalmia and the cross sectional area of water course is injectd in 3/10 ~ 6/5, so that can effectually discharge into the hydrophthalmia of this size scope with the required mud of well drilling and the detritus that produces through the cutting tooth cutting on the wing in the reverse circulation drilling process, and the cavity in the water course entering drilling rod in the linkage segment, discharge to ground finally, whole reverse circulation drilling process has avoided mud and detritus to block up the condition of hydrophthalmia 7 and has taken place, drilling efficiency is further improved, and the normal work of well drilling has been guaranteed.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (10)
1. A drill bit for reverse circulation drilling, comprising: a bit body including a connecting section and a cutting section disposed axially;
the connecting section is internally provided with a water channel arranged along the axial direction of the connecting section;
the cutting section is provided with at least two blades, the blades are provided with cutting teeth, the cutting section is provided with at least two water holes, the first end of the water channel is communicated with the inner cavity of the drill rod, and the second end of the water channel is communicated with the water holes, so that mud and rock debris generated in drilling can enter the water channel from the water holes;
the ratio of the cross-sectional area of the water hole to the cross-sectional area of the water channel ranges from 3/10 to 6/5;
the cutting section is further provided with a flow guide groove, one end of the flow guide groove extends to the edge of the cutting section, and the other end of the flow guide groove is communicated with the water hole.
2. The drill bit for reverse circulation drilling according to claim 1, wherein the ratio of the cross-sectional area of the port to the cross-sectional area of the waterway is in the range of 1/2-1/1.
3. The reverse circulation drilling bit of claim 1, wherein the channels are disposed adjacent to the sidewalls of the blades.
4. The reverse circulation drilling bit of claim 3, wherein there are at least two of the channels, one blade corresponding to at least one of the channels.
5. The reverse circulation drilling bit of claim 1, wherein each blade is provided with at least one of the water holes on a side thereof.
6. The reverse circulation drilling bit of any one of claims 1-5, wherein the blades comprise a first blade and a second blade, the first blade having a length greater than the second blade, a first end of the first blade extending to a middle of the cutting section and a second end of the first blade located at an edge of the cutting section.
7. The reverse circulation drilling bit of claim 6, wherein the first blade is recessed from an edge of the cutting section toward a middle.
8. The reverse circulation drilling bit of claim 6, wherein a first end of the second blade faces the port and a second end of the second blade is located at an edge of the cutting section.
9. The reverse circulation well drilling bit according to any one of claims 1 to 5, wherein a protective layer is arranged on the inner wall and the opening of each water hole.
10. A drill bit for reverse circulation drilling according to any one of claims 1 to 5, wherein the cross-sectional shape of the port is circular.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811103302.6A CN110924872A (en) | 2018-09-20 | 2018-09-20 | Drill bit for reverse circulation drilling |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811103302.6A CN110924872A (en) | 2018-09-20 | 2018-09-20 | Drill bit for reverse circulation drilling |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110924872A true CN110924872A (en) | 2020-03-27 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811103302.6A Pending CN110924872A (en) | 2018-09-20 | 2018-09-20 | Drill bit for reverse circulation drilling |
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| Country | Link |
|---|---|
| CN (1) | CN110924872A (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112049576A (en) * | 2020-10-20 | 2020-12-08 | 西南石油大学 | Three-channel drill bit |
| CN114278230A (en) * | 2021-12-30 | 2022-04-05 | 库尔勒施得石油技术服务有限公司 | Reverse circulation drill bit |
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| CN206571429U (en) * | 2017-03-10 | 2017-10-20 | 昆明冶金高等专科学校 | A kind of mining machinery mining drill bit |
| CN209067118U (en) * | 2018-09-20 | 2019-07-05 | 中国石油天然气股份有限公司 | Drill bit for reverse circulation drilling |
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| WO1996024744A1 (en) * | 1995-02-07 | 1996-08-15 | Brit Bit Limited | Improvements in or relating to drill bits |
| US20110266071A1 (en) * | 2009-01-14 | 2011-11-03 | Lind William H | Rotary Drill Bits with Optimized Fluid Flow Characteristics |
| CN203097725U (en) * | 2013-03-20 | 2013-07-31 | 成都惠灵丰金刚石钻头有限公司 | Three-cutter-wing large opening reverse circulation drill |
| CN203867474U (en) * | 2013-12-30 | 2014-10-08 | 中国海洋石油总公司 | Drill bit structure suitable for fast drilling pelinite |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112049576A (en) * | 2020-10-20 | 2020-12-08 | 西南石油大学 | Three-channel drill bit |
| CN114278230A (en) * | 2021-12-30 | 2022-04-05 | 库尔勒施得石油技术服务有限公司 | Reverse circulation drill bit |
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