DD158714A3 - METHOD FOR PRODUCING A DOUBLE CORE TUBE STABILIZER - Google Patents

Abstract

For the extraction of rock samples in the deep drilling technique double core tubes were used. In order to avoid bending out of these double core tubes, stabilizers are used, which are mounted on the outer tube transition of the double core tube. It is a simple and inexpensive method of manufacture to provide the stabilizer or parts thereof reusable. According to the invention, the production method provides that a metal skeleton is shrunk onto a compact core by sintering, whereby ribs and recesses of the metal skeleton are formed by a negatively formed mother mold and sintered shaped parts of a hard metal are sintered in the outer surfaces of the ribs and subsequently the core becomes a thin-walled sleeve is turned off. The entire stabilizer is applied to the prepared outer tube transition and firmly welded on the front side.

Description

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Process for producing a double core tube stabilizer

Field of application of the invention

The invention relates to a method for producing a Doppslkernrohrstabilisators.

For the extraction of rock samples in Tiefborhrtechnik double core tubes are used. To avoid bending out of the double core tube or reduce su, stabilizers are used, which are mounted on the outer tube junctions of the double core tube.

Characteristic of the Known Technical Solutions It is known to provide the outer tube junctions of a double core tube with a series of individual stabilizer ribs. These stabilizer ribs are welded longitudinally on the outer tube transition. The production of the one ribs is very expensive and their attachment to the outer tube transition by welding excludes the reuse of the parts which have not yet worn out when the outer tube transition or one or more stabilizer ribs wear out. However, since both the outer tube transition and the stabilizer ribs made of high quality materials, this is no economic material use given.

It is also known that the stabilizer consists of a hollow cylindrical steel body having ribs and recesses, which are machined out of the steel body. On the ribs steel sheets are welded with attached carbide (DB-OS 2134 378).

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Also, this stabilizer is a complex and difficult-to-manufacture component that is also not reusable when worn.

Object of the invention

The object of the invention is to provide a simple and inexpensive manufacturing method for a wear-resistant Doppelkernrohrstabilisator that completely surrounds the outer pipe transition, being designed easily and easily assembled or disassembled and another or reusable wear of individual functional elements of Doppelkernrohrstabilisators guaranteed.

Explanation of the essence of the invention

The invention has for its object to provide a method for producing a Doppelkernrohrstabilisators au, in which an annular sleeve surrounded by a ring of ribs with a wear-resistant outer surface and is fixedly disposed on the outer tube transition. This is achieved in that, according to the invention, a metal skeleton is shrunk onto a compact steel core by sintering, the ribs and exceptions being formed by a negatively formed mother mold and sintered carbide fittings in the outer surfaces of the ribs. Subsequently, after the sintering process, the compact steel core is turned out to form a thin-walled sleeve, which is pushed onto the prepared outer tube transition of the double core tube and welded to the front side.

embodiment

The invention is explained in more detail below using an exemplary embodiment.

In the accompanying drawing show:

1 shows the longitudinal section through an arranged on an outer tube passage inventively produced Doppelkernrohrstabilisator

2 shows a cross section through a Doppelkernrohrstabilisator according to the invention of FIG .. 1

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Corresponding to the length of a double core tube, a different number of outer tube junctions 1 in the double core tube are screwed at equal distances from each other. On each outer tube transition 1, a thin-walled sleeve 2 is arranged. The thin-walled sleeve 2 is surrounded by a sintered metal frame 7. The strength of the sintered metal frame 7 corresponds to the time required for the annular space between the double core pipe and the borehole wall. The matrix 7 is provided on its surface at equal intervals with a number of ribs 3 in accordance with the intended use of the stabilizer. Between the ribs 3, the same number of recesses 4 are provided. The arranged between the ribs 3 recesses 4 serve the flow of the circulating drilling fluid. In the outer surfaces 6 of the ribs 3 fittings 5 made of hard metal, sintered. The number and shape of the ribs 3 and depending on the number of recesses 4 determined by the particular application.

The double-core tube stabilizer is manufactured according to the following procedure and fixed on the outer tube transition 1 of a double-core tube:

On a compact steel core or a very thick-walled tube, a metal framework 7 is shrunk by sintering. To form the outer shape of the stabilizer, the metal framework 7 for the sintering process of a negative mother shape amgeben. Ribs 3 and recesses 4 are provided in each case in their negative training in the Mitterform. To achieve a tight fit of Me tallgerüst it 7 on the steel core, this is provided with the annular groove 8. The mother mold is further formed so that in the negative formation of the outer surface 6 of the ribs 3 a certain number of recesses are provided for the fittings 5 made of hard metal. The shaped pieces 5 of cemented carbide are sintered into the metal frame, so that a wear-resistant Hartmetallbestüokung on the outer surfaces 6 of the ribs 3 is achieved.

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Fach Completion of the sintering process it is the compact steel core turned out to a thin-walled sleeve 2 »The outer shape of the stabilizer is finished by the sintering process and requires no rework. Subsequently, the Doppelkernrohrstabilisator on the prepared, that is externally processed accordingly outer tube transition 1 is pushed. To fix the stabilizer, the thin-walled sleeve 2 is welded to the outer tube transition Λ on the face side. This ensures on the one hand a fixed arrangement of the stabilizer on the double core tube. On the other hand, it is always possible by twisting or otherwise removing the weld, the sleeve 2 and thus the stabilizer again from the outer pipe transition Λ to solve.

The invention achieves the following advantages:

1. Simple and cheap manufacturing process

2. A reuse of the stabilizer is guaranteed at all times.

3. A particular advantage of the use of stabilizers according to the invention is further to be seen in that overall the wear of all parts is substantially reduced. Moreover, a reuse of intact functional elements is given.

4. Due to the stabilization or, stiffening of double core tubes with the stabilizers according to the invention, the Schwirr- and tilting effect on the drilling tool and the bending stresses for the core drill decreases overall. This results in a positive effect on the kraftverschraubten threaded connections of the double core tube.

5. Reducing the bending stress of the core drilling machine also reduces the mechanical stress on the core material being drilled.

Claims (1)

^. Z191 1 7 - Erfindungsanspruoh Λ, A method for producing a Doppelkernrohrstabilisators having a thin-walled sleeve with recesses and ribs and the hooks are provided with a trim of hard metal, characterized in that on a compact steel core by sintering a metal skeleton is shrunk, wherein the ribs and recesses of the metal frame formed by a negative-trained mother mold and sintered into the outer surfaces of the ribs shaped pieces of a hard metal, and that subsequently turned out of the compact steel core to a dünnv / andigen sleeve, this is pushed onto an outer tube transition of the stabilizer and welded frontally. For this iSeite drawing