RU1819980C - Core barrel - Google Patents

Abstract

Usage: core drilling. SUMMARY OF THE INVENTION: A core sampling tool comprises a drill head 1, a housing 2 in which a core receiver 3 is placed, equipped with elastic elements k, the ends of which are directed obliquely upstream of the core. The core receiving pipe 3 is placed in the housing 2 with an eccentricity between the axes of the housing and the core receiving pipe. Moreover, the elastic elements are placed only on the eccentricity side. During drilling, the body 2 rotates and the head 1 and the core receiver pipe 3 fixed therein are drilled. After drilling the first core column 5, it enters the core receiver pipe into an eccentrically located section and is pressed against the elastic elements, gradually filling the core receiver pipe. 2 ill. ate with

Description

The invention relates to the mining and oil and gas industries, in particular to devices used for drilling coring wells.

Known for the closest in technical essence and the achieved result to the invention core sampling tool d, including a drill head, body, core pipe located coaxially relative to the body, equipped with elastic elements, the ends of which are directed obliquely upstream of the core ..

A drawback of a core sampling apparatus is the probability of self-jamming of the core due to its accumulation due to the impossibility of moving from the bottom up and the possibility of displacement of the crushed core.

The aim of the invention is to prevent self-sticking of the core by preventing it from accumulating in the core collection pipe from the bottom up and displacement down the core collection pipe.

The goal is achieved in that in a core sample containing a drill head, a body, a core receiving pipe placed therein, equipped with elastic elements, the ends of which are directed obliquely upstream of the core, the core receiving pipe is eccentric, and the elastic elements are located on the eccentricity side.

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The invention is as follows.

The presence of eccentricity creates centrifugal forces that, when the core is rotated, acts on each individual core column, while in the zone of contact of the column or part of the core column with the surface of the elastic elements located on the eccentricity side, a friction force arises equal to or greater than the weight of the core column in working fluid

In a core sample, the gravity of the core column is balanced against the wall of the core receiver pipe. At the same time, in the presence of longitudinal vibrations of core sampling usually occurring during drilling especially hard rocks, the frequency of which provides an acceleration of the motion of the projectile and core, greater than the acceleration of gravity, in the phase of movement from the bottom up, the core is picked up by the bent ends of wires or plates of elastic elements , the ends of which are directed obliquely upstream of the core, and moves with the pipe up along the direction of the free ends of the wire or plate elements of the core receiver pipes.

In the phase of oscillation of the projectile and the core toward the bottom of the shell, the projectile with the core receiving tube moves at a speed greater than the rate of free fall of the core in the fluid. Due to the low coefficient and friction force between the core and the elastic elements of the core receiver pipe, when moving downward, the core receiver pipe is shifted down relative to the core, or, in other words, the core moves upward relative to the core receiver pipe. Subsequently, at each oscillation, the process is repeated and each individual column or core fragment moves along the core-receiving (core-water) pipe from bottom to top, without interfering with the next core column entering the core-receiving pipe. Thus, there is 1 subsequent filling of the core receiving pipe from top to bottom.

Figure 1 shows a core sample d, in section; on, figure 2 - section aa in figure 1.

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The core sample contains a rile head 1, body 2, on which a core receiver 3 is placed, equipped with elastic elements 4, the ends of which are directed obliquely upstream of the core. Elastic elements can be represented by a pile of bent along the core (above the horizontal plane) from the bottom up wire and plate elastic elements. The core receiver pipe 3 is placed in the housing 2 with an eccentricity Ј. between the axes of the housing and the core receiver pipe. The magnitude of the eccentricity is almost equal to the radius of rotation R of the center of mass of the core column 5, since the elastic elements are located only on the eccentricity side, i.e. from the side to which the axis of the core-receiving pipe is shifted, there is no radial displacement of the core column towards the wall of the core-receiving pipe with elastic elements (it is assumed that the thickness of the pile of elastic elements is approximately equal to the radial clearance on the side between the inner wall of the core-receiving pipe and the side surface of the core-core and core located concentrically with a core receiving pipe). The calculation of eccentricity is carried out according to a certain procedure.

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Coring shell d works as follows.

When drilling with coring, the body 2 rotates and the head 1 and the core receiving pipe 3 fixed therein rotate. The drillable core 5 enters the core receiving pipe, namely its part coaxially located in the housing. The column can break off itself (when drilling in fractured rocks) or it can be broken off into separate columns of a pre-selected length by a special core breaker known to specialists in construction (not shown in the figures). When the core column gets into an eccentrically located section of the core-receiving pipe and rotates with it, the core column is pressed against the pile - elastic elements by the action of centrifugal force and freezes due to the friction force of the core column on the surface formed by the ends of the elastic elements k bent upwards equal to or exceeds the weight of the core column in the drilling fluid.

Editor T. Yurchikova

Compiled by M.Vorozhbitov

Tehred M. Morgenthal Corrector A. Kozoriz

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