A kind of two-way injection core bit of reduction chip hold down effect
The utility model relates to oil drilling CORING TECHNOLOGY field, in particular to the two-way injection of a kind of reduction chip hold down effect takes
Heart drill bit.
Rock core is most direct, the most complete record obtained in petroleum exploration and development process, passes through drilling and coring delivery work
Tool, rock core can completely be taken out from underground to ground.Core bit is mounted on the lower part of coring tool, and there is a circle at middle part
Hole, during core-drilling, core bit rotary cutting formation rock forms a core column and passes through the circular hole in the middle part of drill bit
Into coring inner drum, rock core is maintained in coring inner drum by specifically cutting heart mode, pulls out of hole and completes coring operation.
The current well overwhelming majority for having coring to design all uses Overbalance Drilling, i.e. shaft bottom head of liquid is greater than ground lamination
Power can not only enhance the hardness of bottom rock in the normal pressure that shaft bottom generates, can also landwaste be prevented to leave shaft bottom, lead to landwaste weight
It is multiple broken, rate of penetration is reduced, this phenomenon is known as " chip hold down effect ".During drilling and coring delivery, due to worrying that rock core is drilled
Well liquid erosion, therefore frequently with smaller displacement when normal drilling well (about 2/3rds), drilling well flow velocity becomes smaller in annular space,
Large rock-carrying ability reduces, and landwaste and well wall dropping block are possible to be deposited on core bit and lead to the generation of down-hole accident.
Utility model content:
The technical problem to be solved by the present invention is to provide a kind of two-way injection core bit of reduction chip hold down effect, the dresses
Setting realizes the influence that can be effectively reduced chip hold down effect, improves coring drilling speed, shortens the coring construction time, reduces rock core punching
Erosion improves core recovery, while guaranteeing the large rock-carrying ability of drilling fluid in annular space, prevents landwaste and well wall dropping block in core bit
Top accumulation reduces the possibility that accident occurs.Overcoming existing core bit is influenced big, rate of penetration drop by chip hold down effect
Deficiency low, that rock core is easily accumulated by drilling fluid erosion, landwaste and well wall dropping block on core bit top.
Technical solution adopted in the utility model is: a kind of two-way injection core bit of reduction chip hold down effect, including takes
Heart drill body, core bit body central are provided with central passage, and core bit body lower part is evenly equipped with multiple wings；Column drill
Head ontology upper end connects outer cylinder, and core bit inner body wall connects inner cylinder and sealed by sealing ring, ring between outer cylinder and inner cylinder
Sky is connected with the lower injection hydrophthalmia of core bit body interior, and lower injection hydrophthalmia lower end outlet is arranged at core bit ontology bottom
End, each wing inside are equipped with drilling fluid upgoing flow passages, and the import of drilling fluid upgoing flow passages is connected to lower injection hydrophthalmia, on drilling fluid
Top nozzle is installed, top nozzle is threaded on core bit body outer wall at row runner exit.
Top nozzle is made of cemented carbide material.
Drilling fluid upgoing flow passages are arranged obliquely and outward.
The beneficial effects of the utility model are: the utility model realizes the influence that can be effectively reduced chip hold down effect,
Coring drilling speed is improved, the coring construction time is shortened, reduces core erosion, improves core recovery, while guaranteeing drilling well in annular space
The large rock-carrying ability of liquid prevents landwaste and well wall dropping block from accumulating on core bit top, reduces the possibility that accident occurs.
Detailed description of the invention:
The utility model is described in more detail with reference to the accompanying drawings and detailed description.
Fig. 1 is the structural schematic diagram of the utility model.
Fig. 2 is the schematic diagram that the utility model is connected with inner cylinder, outer cylinder.
As shown in Figure 1 and Figure 2, a kind of two-way injection core bit of reduction chip hold down effect, including core bit ontology 1, coring
1 center of drill body is provided with central passage 6, and 1 lower part of core bit ontology is evenly equipped with multiple wings 4；1 upper end of core bit ontology
Outer cylinder 7 is connected, 1 inner wall of core bit ontology connection inner cylinder 8 is simultaneously sealed by sealing ring 9, and ring between outer cylinder 7 and inner cylinder 8 is prevented
Drilling fluid in sky enters central passage 6.Annular space and the lower injection hydrophthalmia inside core bit ontology 1 between outer cylinder 7 and inner cylinder 8
5 are connected, and lower 5 lower end of injection hydrophthalmia outlet setting is equipped on drilling fluid inside 1 bottom end of core bit ontology, each wing 4
Row runner 3,3 import of drilling fluid upgoing flow passages are connected to lower injection hydrophthalmia 5, and 3 exit of drilling fluid upgoing flow passages is equipped with spray
Mouth 2, top nozzle 2 flow to contrary with lower injection hydrophthalmia 5, and top nozzle 2 is threaded on 1 outer wall of core bit ontology.
Top nozzle 2 is made of cemented carbide material.
Drilling fluid upgoing flow passages 3 are arranged obliquely and outward.
In core-drilling using discharge capacity equally big when typical well, it is ensured that drilling fluid takes rock energy in annular space
Power prevents landwaste and well wall dropping block from accumulating on 1 top of core bit ontology, reduces the possibility that accident occurs.Due to top nozzle 2
In the presence of a part of drilling fluid does not contact and erosion shaft bottom, but reversed rear injection upwards, it is possible to reduce shaft bottom head of liquid,
Shaft bottom forms local near-balance drilling or under balance pressure drilling, reduces or releases chip hold down effect, improve rate of penetration.Since shaft bottom is pressed
Difference reduces, and formation rock axial compressive force reduces, and formation hardness decreases, and rate of penetration can also be made to improve.Pass through lower injection
Hydrophthalmia 5 contacts the discharge capacity that the drilling fluid displacement in shaft bottom requires for core-drilling, reduces erosion of the drilling fluid to core column, improves rock
Heart yield rate.
It is understood that being merely to illustrate the utility model above with respect to the specific descriptions of the utility model and not being
It is limited to technical solution described in the utility model embodiment, those skilled in the art should understand that, it still can be with
It modifies to the utility model or equivalent replacement, to reach identical technical effect；Needs are used as long as meeting, all in this reality
Within novel protection scope.