CN2082755U - Deflecting inserted tooth three-gear bit - Google Patents

Abstract

The utility model relates to a deflecting inserted tooth three-cone bit for the petroleum and natural gas drilling, which is different from the structure of the existing inserted tooth three-cone bits. The deflecting inserted tooth three-cone bit is characterized in that the center line of the inserted teeth of the bit is not parallel to the generating line of the cones of roller cones. When the bit is in an inverted position, the center line of the tooth top of the inserted teeth deflects centain degrees counterclockwise oppositely to the generating line of the cones of the roller cones. According to different stratigraphic conditions, so long as different deflection angles are adopted by the different tooth rings of each roller cone without changing other structural parameters, the utility model has the advantages of high efficiency and low cost.

Description

Deflecting inserted tooth three-gear bit

The utility model relates to a kind of tri-cone insert bits, is specially adapted in oil and the gas drilling dead-soft to medium ground, in order to improve the drill bit efficiency of breaking rock.

At present domestic and international employed tri-cone insert bits mainly all is made up of tooth pawl, gear wheel and the tooth inlayed, wherein the insert mode of chisel teeth and scoop chisel insert all is to make tooth tooth top center line parallel with the gear wheel cone generatrices, the drill bit of this structure has influenced the efficiency of breaking rock of tooth in the shaft bottom to a certain extent, and the rate of penetration when creeping into is lower.This is because when tricone bit crept into, tooth can produce in the shaft bottom and radially slide and tangential the slip.Tangential sliding speed is the sliding speed tangent with the track garden of tooth, the speed of radially sliding is meant tooth along the sliding speed of gear wheel axis on the projecting direction of shaft bottom, and tangential sliding speed is exactly the sliding speed of tooth in the shaft bottom with the sum velocity that radially slides speed.The tooth of existing various drill bit all is to form by the tooth tooth top center line structure insert parallel with the gear wheel cone generatrices, the tricone bit of this structure is not vertical in the sliding speed direction in shaft bottom with tooth because of tooth tooth top center line, so tooth the shaft bottom to scrape tangent plane long-pending less, efficiency of breaking rock is lower.But the purpose of this utility model is to provide a kind of deflection tri-cone insert bits of efficient rock-breaking, and it is long-pending corresponding increase tooth to scrape tangent plane, improves efficiency of breaking rock.

The utility model is compared with existing various drill bit, the parts of forming are identical, mainly all be by the tooth pawl, gear wheel and tooth are formed, difference be on the utility model tri-cone insert bits inner each gear ring have a denture made tooth tooth top center line with respect to the deflection of gear wheel cone generatrices certain angle θ, tooth deflection angle on the different gear rings of each gear wheel is different substantially, yawing moment should guarantee when drill bit during at upside down position, in the face of gear wheel, tooth tooth top center line is with respect to the counter-clockwise deflection of gear wheel cone generatrices direction, and the selection of deflection angle should guarantee that tooth tooth top center line and the tooth on each toothrow circle is perpendicular in shaft bottom sliding speed direction.

The big I of deflection angle theta is determined by following algebraic expression:

$\mathrm{\θ}=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\mathrm{arctg}\left(\frac{{\mathrm{\λ}}_{r}r{\mathrm{\ω}}_2}{{\mathrm{\ρ\ω}}_0-{\mathrm{\λ}}_{2}r{\mathrm{\ω}}_i}\right)$

${\mathrm{\λ}}_r=\frac{{0.5r\cos \mathrm{\β}}^2\sin 2\mathrm{\α}-C\sin \mathrm{\β}\sin \mathrm{\α}-S\cos \mathrm{\α}}{\mathrm{\ρ}}$ ${\mathrm{\λ}}_t=\frac{C\cos \mathrm{\α}-S\sin \mathrm{\β}\sin \mathrm{\α}+r\sin \mathrm{\β}}{\mathrm{\ρ}}$

$\mathrm{\ρ}=\sqrt{{(C+r\sin \mathrm{\β}\cos \mathrm{\α})}^2+{(r\sin \mathrm{\α}-S)}^2}$

R is the gear ring radius, ω _oBe drill bit rotational angular velocity, ω _iBe the gear wheel rotational angular velocity, β is the complementary angle of drill axis and gear wheel axis angle, and S is a cutter offset, C be gear ring center to the distance of drill axis at gear wheel axial plane upslide shadow, α is a bit around the angle of gear wheel rotational on the tooth tooth top center line.These parameters all can be determined by theoretical and experiment.The utility model has utilized the deflection of tooth, makes tooth tooth top center line and tooth on each toothrow circle of three gear wheels perpendicular in shaft bottom sliding speed direction, has increased tooth scraping area effectively, has improved the rate of penetration of drilling well.The utility model is after improving on original tri-cone insert bits basis, and the drill bit processing cost is constant substantially.

The utility model is described in further detail below in conjunction with accompanying drawing:

Accompanying drawing is the general assembly drawing of tri-cone insert bits that the utility model is described;

1 is the tooth pawl; 2 is gear wheel; 3 is tooth, and A is to the yawing moment of view sign deflection angle theta, and angle θ is in 0 °～40 ° scopes for the described tooth tooth top of the utility model center line optimum deflection.

The site test results of using the utility model to carry out shows, behind employing the utility model, has improved the efficiency of breaking rock of tri-cone insert bits significantly, and rate of penetration can improve 18.9%～80%, has reduced drilling cost widely, has improved economic benefit.

Claims (2)

1, a kind of tri-cone insert bits that is used for oil and gas drilling, mainly by the tooth pawl, gear wheel and tooth are formed, and it is characterized in that said tooth tooth top center line is with respect to gear wheel cone generatrices direction deflection certain angle.

2, by the described tri-cone insert bits of claim 1, tooth tooth top center line 0 °～40 ° angles of the counter-clockwise deflection of gear wheel cone generatrices direction relatively when it is characterized in that drill bit is in upside down position.

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