SU1472616A1 - Crown bit - Google Patents

Abstract

The invention relates to drilling wells with core sampling during exploration and production operations. The goal is to increase crown durability by eliminating the effect of radial forces on adjacent incisors. The crown includes a housing 1 with a connecting thread 2 and a holder 3. They are equipped respectively with core and well-forming cutters 4 and 5 with cutting edges. The latter are installed in the plan along the same line and with the displacement of the incisors 5 in the direction of the connecting thread 2. Between the incisors 4 and 5, the gaskets 6 are installed with the full overlapping of their side faces in width. The thickness of the gaskets Δ is associated with the offset Δ * 98N of the cutters 4 and 5 by the ratio Δ / Δ * 98H = 0.25-0.35. MATERIAL OF GASKET 6 HAS LESS STRESS, THAN MATERIAL OF THE BODY 1. AT THE EXPENSIVE CHANGE OF THE THICKNESS OF THE GASKET 6 PART OF THE RADIAL LOAD IS TRANSFERRED TO RELATED CUTTERS AND WITHDRAWS FROM THEIR STRUCTURE. WHEN INCREASING THICKNESS THICKNESS 6, DEPEND THE CROWNS ON UNDEFREDTED RING BANDS OF BREED, FORMED FROM A COMPLETELY OVERRUPTED BORING WELLS CUTTERS 4 AND 5.1 Z.P. Ф-ЛЫ, 2 IL.

Description

FIG.

The invention relates to a rock-breaking tool, namely to crowns for drilling wells with coring during exploration and production operations.

The purpose of the invention is to increase the crown durability by eliminating the effect of radial forces on adjacent incisors.

FIG. 1 shows a drill crown, general view; in fig. 2 - the same in terms of.

The drill crown contains a cylindrical body 1 with a connecting thread 2 and a holder 3, in which core-and well-forming cutters 4 and 5 are fixed, respectively, the cutting edges of which in the plane are installed along the same line and offset D / g in the vertical plane of front-forming cutters 5 in the direction of the connecting thread 2. Between the core-forming cutters 4 and the well-forming cutters 5 are installed gaskets 6 of soft metal, such as aluminum, with full overlapping of the lateral faces of the core-forming 4 and well-forming x 5 incisors in width, with a thickness, and inb of the gasket 6 is associated with the height of the displacement D / g of incisors by the ratio b / D / g of 0.25-0.35.

The crown works as follows.

Under the action of axial load and torque, core-forming cutters 4 and well-forming cutters 5 are inserted into the drilled rock and destroy it. Destroyed rock is carried by the flushing fluid to the surface.

The use of shims 6 between core and wellbore cutters 4 and 5 protects adjacent wellbore cutters 5 from radial loads from the core, and core-forming cutters 4 from radial loads from the borehole walls. In the proposed crown, the radial loads will be transferred from the cutters 4 and 5 to the gaskets 6, which, due to their performance from a less rigid material as compared to the material of the body 1, will absorb the radial loads due to plastic deformation without causing the breakage of brittle carbide cutters 4 and 5. Preff

The ratio between the thickness 6 of the gaskets 6 and the displacement height DL of the cutters 4 and 5 is established experimentally. At b / d / g less than 0.25 and more than 0.35, a decrease in both the mechanical drilling rate and penetration rate is observed. This is due to the fact that when 5 / D / g changes, by reducing the thickness of the gaskets 6, a portion of the radial load is transferred to adjacent incisors and taken out of them, and as the thickness of its thickness increases, there are cases of crowns hanging on the intact annular rock sections formed from - for the incomplete blocking of the bottom hole with incisors.

Changing this ratio by reducing the height of the displacement D / i leads to the loss of the stepped bottom effect, and increasing D / g leads to deterioration of the working conditions of the borehole cutters 5.

Performing a crown with a ratio of 5 / D / 1 0.25-0.35 improves the crown's resistance and reduces the energy intensity of the rock destruction process, which increases the overall performance of the crown.

Claims (2)

1.Burov crown, comprising a housing with a connecting thread and a holder, equipped, respectively, with core and bore-forming cutters with cutting edges set in plan along one line and with displacement of the well-forming incisors towards the connecting thread, characterized in that, in order to increase the crown durability by eliminating the effect of radial forces on adjacent ridges, it is equipped with gaskets installed between the well and core-forming cutters with full overlapping of their side faces along the width, while the thickness of the gaskets 6 is associated with the displacement of D / g cutters the ratio b / d / g 0,25-0,35. 2. A drill crown according to claim 1, characterized in that the gasket material has a lower stiffness than the material of the body.