US3241623A - Coring apparatus - Google Patents

Description

March 22, 1966 J. D. MARTINEZ GORING APPARATUS Filed Sept. 18, 1965 FIG.IA.

INVENTOR.

JOSEPH D- MARTINEZ,

ATTORNEY.

United States Patent 3,241,623 CORING APPARATUS Joseph D. Martinez, De Kalb, Ill., assignor, by mesne assignments, to Esso Production Research Company, Houston, Tex., a corporation of Delaware Filed Sept. 18, 1963, Ser. No. 309,822 5 Claims. (Cl. 175-44) This invention relates to the taking of a subsurface core and the orienting of the subsurface core. More particularly, this invention is a novel apparatus for obtaining an oriented subsurface core.

During the drilling of a borehole in the search for oil or other minerals, core samples are cut from the formations being traversed and are removed to the earths surface for examination. Various, important information can be obtained from such a core. For example, if any bedding planes are observable in the core, the strike and dip of these planes (and hence of the formation from which the core was obtained) can be determined. The true directions of strike and dip, however, can be determined only if the core can be oriented (in space) in the same Way that it was oriented in its original place in the formation.

There are several methods now in use which are satisfactory for orienting a core if the core is preserved intact. If, however, the core is broken into segments, as is frequently the case, and the segments cannot be fitted together, then only the orientation of the topmost segment will be preserved. The apparatus to be described herein preserves the orientation of the entire core even if it is broken into segments.

Briefly described, my new apparatus for cutting a core from the bottom of a borehole comprises a first tubular member having a cylindrical cavity formed therein. A second tubular member is positioned within the cavity formed in the first tubular member. The bores of the two tubular members have approximately the same diameter. The first tubular member is rotated about the second tubular member during the cutting of a core. A scratcher extends from the second tubular member into the bore thereof.

The scratcher is maintained in continuous contact with the side of the core as the core is being cut. The result is that a mark on the core is provided and can be traced from top to bottom when the segments of the core are fitted together.

The invention, as well as its many advantages, may be further understood by reference to the following detailed description and drawings in which:

FIGS. 1 and 1A are longitudinal, sectional views showing the general arrangement of my new apparatus; and

FIG. 2 is a view taken along line 2-2 of FIG. 1.

Referring to the drawings and more particularly to FIG. 1, numeral refers to a sub on the lower section of a drill string which is lowered into the borehole. Threadedly connected to the sub 10 of the drill string is an outer core barrel 12. Threadedly connected to the outer core barrel 12 is a core bit 14 used in drilling the core 16. As the core bit 14 is rotated, the core 16 is forced upwardly through a core catcher 18 which is attached to the lower extremity of an inner barrel 20. The upper portion of the inner barrel 20 is connected to a rod 22. The rod 22 extends to the lower portion of the drill string sub 10. Connected to the lower portion of the drill string sub 10 and forming an integral part thereof is a. sleeve member 24. It can be seen from an examination of FIG. 1 that the sub 10, the outer core barrel 12, and the sleeve member 24 rotate with the core bit 14 when the drill string is rotated to cut the core 16. The rod 22 to which the inner barrel 20 is attached remains stationary ice as the core 16 is forced into the inner barrel 20. Suitable bearings 26 are positioned between the rod 22 and the sleeve member 24 to provide for the rotation of the rotating members about the stationary members. To prevent any of the circulating fluids from getting into the bearings 26, suitable packing means 28 and 29 are provided.

The usual core-orienting means shown in dotted lines are provided in the upper chamber of sub 10' to properly orient the core within the borehole.

Referring to FIGS. 1 and 2, it can be seen that the outer core barrel 12 contains a substantially cylindrical cavity 30. The substantially cylindrical cavity 30 is formed by providing a series of an upper step 32 and lower step 34, upper step 36 and lower step 38, and upper step 49 and lower step 42. The cavity 30 thus decreases in height as it extends from the bore 44.

A tubular member 46 having a bore 48 of substantially the same diameter as the bore 44 in outer core barrel 12 is mounted within the cavity 30. The tubular member 46 is provided with an upper shoulder 50 and a lower shoulder 52.

A chamber 54 is formed in the tubular member 46. The chamber 54 extends from the bore 48 to a point within the tubular member 46. A scratcher 56 having a point 58 is mounted Within the chamber 54. The point 58 of scratcher 56 extends into the bore 48 because of the bias of coil spring 60. An upper circular race 62 and a lower circular race 64 are mounted on the steps 36 and 38, respectively, within outer core barrel 12. An upper circular race 66 and a lower circular race 68 are mounted on the shoulders 50 and 52, respectively, of tubular member 46. Races 62 and 66 provide a raceway for a plurality of ball bearings 70. Races 64 and 68 provide a raceway for a plurality of ball bearings 7.2.

A circular groove 74 and a circular groove 76 are formed in the inner surface 78 and outer surface 80, respectively, of outer core barrel 12 and tubular member 46, respectively, to form a bearing raceway. A plurality of roller bearings 82 is circularly mounted within the grooves 74 and 76.

In operation, as the core 16 is being cut, the outer core barrel 12 rotates about the tubular member 46. As the core 16 is cut, the point 58 of scratcher 56 forms a mark 84 in the core 16 extending from the top of core 16 vertically downward. The tubular member 46 is prevented from rotating appreciably by the scratcher. Hence, even if the core 16 should break into segments as it is removed at the surface of the earth, the mark 84 on core 16 can be used to fit the segments together. Thus, the orientation of all the segments of the core is preserved.

I claim:

1. In an apparatus for cutting a core from the bottom of an earth bore: a first tubular member having a substantially cylindrical cavity formed therein; a second tubular member positioned in said cavity and having substantially the same inside diameter as the first tubular member; means adapted to permit the rotation of the first tubular member about the second tubular member during the cutting of a core; and a single scratcher extending from the second tubular member into the bore thereof.

2. An apparatus in accordance with claim 1 wherein said second tubular member has a chamber formed there in from its inside perimeter, biasing means is mounted in the chamber, and the scratcher is biased into the bore of the second tubular member by the biasing means.

3. An apparatus in accordance with claim 1 wherein the means adapted to permit the rotation of the first tubular member about the second tubular member during the cutting of a core includes a plurality of rollers circularly mounted within the substantially cylindrical cavity.

4. An apparatus in accordance with claim 1 wherein the means adapted to permit the rotation of the first tubular member about the second tubular member during the cutting of a core includes: an upper circular race and a lower circular race mounted in the substantially cylindrical cavity; an upper circular race and a lower circular race mounted on the second tubular member, the upper circular race being mounted directly below and the lower circular race being mounted directly above the upper and lower circular races, respectively, mounted in the substantially cylindrical cavity to provide an upper raceway and a lower raceway; and a plurality of ball bearings mounted in each of said raceways.

5. In an apparatus for cutting a core from the bottom of an earth bore: a first tubular member having a substantially cylindrical cavity formed therein; a second tubular member positioned in said cavity and having substantially the same inside diameter as the first tubular member; a plurality of rollers circularly mounted within the substantially cylindrical cavity; an upper circular race and a lower circular race mounted in the substantially cylindrical cavity; an upper circular race and a lower circular race mounted on the second tubular member, the upper circular race being mounted directly below and the lower circular race being mounted directly above the upper and lower circular races, respectively, mounted in the substantially cylindrical cavity to provide an upper raceway and a lower raceway; and a plurality of ball bearings mounted in each of said raceways; a chamber formed in the second tubular member; a single scratcher mounted in the chamber; and biasing means also mounted in the chamber adapted to bias the single scratcher into the bore of the second tubular member.

References Cited by the Examiner UNITED STATES PATENTS 1,701,724 2/1929 McLaughlin 17544 2,580,510 1/1952 Brady 175-44 2,657,013 10/1953 Brady 175-44 CHARLES E. OCONNELL, Primary Examiner,

R. E. FAVREAU, Assistant Examiner.

Claims (1)

1. IN AN APPARATUS FOR CUTTING A CORE FROM THE BOTTOM OF AN EARTH BORE: A FIRST TUBULAR MEMBER HAVING A SUBSTANTIALLY CYLINDRICAL CAVITY FORMED THEREIN; A SECOND TUBULAR MEMBER POSITIONED IN SAID CAVITY AND HAVING SUBSTANTIALLY THE SAME INSIDE DIAMETER AS THE FIRST TUBULAR MEMBER; MEANS ADAPTED TO PERMIT THE ROTATION OF THE FIRST TUBULAR

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