US2089216A - Apparatus for orienting cores - Google Patents

Description

Aug. 10, 1937.

E. D. LYNTON 2,089,216

APPARATUS FOR ORIENTING CORES Filed March 3, 1956 2 Sheets-Sheet l f If INVENTOR.

[oft kart 0 Z y/v/an Aug 10, 1937. LYNTON 2,089,216

APPARATUS FOR ORIENTING CORES Filed March 3, 1936 2 Sheets-Sheet 2 55 56 F1E 4 .67 130 Q1 3 .63

5: an I zz flip 33 ,Fll3 E 56g? 5? 'INVENTOR. /7 BY, [award [2 Zgn/on ATTORNEY.

Patented Aug. 10, 1937'v UNITED STATES APPARATUS FOR ORIENTING oonEs Edward D. Lynton, Glendale, Calif., assignor a Standard Oil Company of California, San Francisco, Calif., a corporation of Delaware 'Application March 3, 1936, Serial No. 66,891

8 Claims.

This invention'relates to the orientation and interpretation of geologic data from cores on samples taken from the earths substrata, and

particularly refers to a method and apparatus for determining the true directionjand degree of inclination of a plane or stratum intersecting a core or sample which has been taken from a bore hole that is not truly verticaL-bdt which is sloped therefrom in a known direction and at a known 10 angle.

In the exploration of the earth's substrata in the search for petroleum, minerals and the like, the direction of inclination of the various strata and the degree of that inclination are of considerable importance, and a great deal of expensive time and efiort are expended to determine them. One procedure is to take a core or samplei'rom a bore hole, and, at the time it is severed from its original position in the earth,

make an identifying mark on it so that, after the core and the drill pipe or other marking tool have been withdrawn from the bore and their,

' movements during withdrawal have been carefully recorded, the original position of the core 5 may be known. Then, by means of a suitable protractor which may be aligned with a stratum or bedding plane intersecting thecore, the direction and degree of inclination. of that stratum with regard to the core axis may be determined.

Inasmuch as'the core has previously been oriented with respect to the earth, the same data may be readily converted to show the direction I and degree of inclination of the stratum with regard to the earth. A suitable apparatus for this purpose is disclosed in the United States Patent No. 1,778,981 issued October 21, 1930, to W. I. McLaughlin.

Other methods of orienting cores or samples as to their original position in the earth make 40 use of magnetic or gyroscopic compasses that are locked, marked or photographed in relation to the core. Another method, to which this invention is applicable, is to photograph the wall of the bore hole and so orient the camera that the direction and degree of inclination of a bedding plane, or line of intersection between adjoining strata may be determined. with such a procedure no core need be taken as will be apparent from the following discussion.

60 In expressing the results of these operations the words strike and dip are commonly employed and will be defined for use in this description. The strike of a stratum or bedding plane adjacent thereto is the direction of the trace or 5 intersection it makes with a truly horizontal plane. The dip of such a stratum or plane is the angle it makes with a. truly horizontal plane. The direction of dip is that in which the plane slopes downwardly from the horizontal, and is at right angles to the strike. It has been found that the methods and means heretofore employed for orienting and interpreting cores gave the apparent strike andthe apparent dip, butnotthe true strike or dip. This wasv found to be due to the deviation of the bore 10 hole from the vertical during the process of coring. Since the recent development of accurate surveying methods and apparatus it is known that deep bores, such as are encountered in oil wells, may be 30 degrees or more from the vertical. If this factor is not taken into account when observing the apparent strike and dip of a stratum or bedding plane contained in an oriented core, the interpretation or the core data may be entirely incorrect. gThe difference between apparent and true dip is especially'large in low angle dips whenever the deviation is as large or larger than the dip. In certain cases the true direction of the dip, after correcting for deviation as outlined below, can be as much as 25 180 degrees 01f the apparent results obtainedby the previously used methods. i

The present invention deals primarily with the correction of the apparent strike and apparent direction and degree of dip of a bedding ,30 plane or stratum, as may be read directly from an oriented core by suitable measuring means such as' a protractor, to take into consideration the direction and degree of the deviation of the 7 axis of the core from a truly vertical line, so that .35 the true strike and true direction and degree" of the dip of the said plane will be known.

An object of this inventionis the/provision of a simple method and means for determining the true strike and degree and direction of dip of a given bedding plane, as from a core or sample, from easily obtained'values: namely, apparent degree and direction of dip of the plane, and deviation direction'and deviationdegree of thecoreaxis. I

Another object ofthe invention is the-provi-' sion of a simple apparatus, into which the values noted may be entered; and which is easily'and quickly manipulated to givethe desired result mote accuracy.

These and other objects and advantages will be more fully apparent, from the following description and from the accompanying drawings,

in a manner that will "prevent mistakes and pro- Z which form a part of this specification, and illustrate a preferred embodiment of this invention.

In the drawings, Figure 1 is a side elevation view of an apparatus embodying this invention, and shows the protractor on which apparent dip is entered.

Figure 2 is a front elevation view on plane IIII of Figure 1, and shows the protractor which indicates true dip.

Figure 3 is a plan view on plane III-III of Figure 1 and shows the scale and protractor on which the core axis deviation direction and degree are entered.

Figure 4 is a plan view on plane IV-IV of Figure 1 and shows the protractor which indicates the true strike.

Referring to the drawings and particularly to Figure 1, the reference numeral l9 designates a horizontal base from which a vertical frame ll extends upwardly. Horizontal arms I2 and I3 are provided to support the movableparts, and are preferably rigidly braced as at l4, I5 and ii, to insure continued and accurateialignment.

A pointer I1 is mounted on a ball l9 secured in socket l9 atthe outer end of the lower arm I3 of frame ll, so that the tip of the pointer may be rotated about the ball l8 as an axis and also moved freely about the center of the ball over the deviation direction protractor and degree scale on the horizontal base ill. At the lower end of pointer I1 is a sliding needle or point 20, received in an axial bore 2| of pointer I1 and urged outwardly by spring 22. An auxiliary pointer 23 is pivoted at 24 on the end of a horizontal arm 25 of pointer l'l so that it is free to move in a plane through the longitudinal axis of pointer II, for a purpose to be described below. Ball l8 maybe clamped in socket i9 as by plate 26 and screws 21 to hold any desired adjustment of pointers l1 and 23. a

A plate 28, with its top surface representing the bedding plane' of the stratum to be determined, is positioned on a sleeve 29 at the upper end of pointer l'l. Plate 28 is pivoted, asby shaft 30 and bosses 3i, so as to be movable relative to sleeve 29 about an axis at right angles to the longitudinal axis of that sleeve and of pointer ll. Sleeve 29 is rotatably mounted on the upper end of pointer I! so that the said sleeve and plate 28 may also be rotated about the langitudinal axis of the pointer in any, position that the latter may be placed. The angle of inclination of plate '28 with respect to the axis of pointer i1 is indicated by suitable means such as an index member 32 on sleeve 29 which cooperates with a protractor 33 secured toand movable with plate 28. A disc 34 secured to pointer l1 below sleeve 29 carries an azimuth protractor 35 similar to that of Figure 4, preferably arranged with the the vertical plane of a 'liary pointer arm 25, for a purpose to be explained below. An indicator hand 38 is secured to sleeve 29 and cooperates with azimuth protractor 35 to show the direction of the plan of protractor 33, which is parallel tothe N-S line of plate 28. A clamp screw 31 serves to secure sleeve 29 and plate 28 in any desired adjustment about the center of pointer l1. A clamp screw 38 on serves to secure protractor 33 and plate 28 in any desired angular adjustment with respect to the axis of sleeve 29 and pointer H. I

On base I0 and vertically below the center of ball socket i9 is a large horizontal protractor 39 (Figure 3) which, in addition to a deviation d1- pression forming lation on pointer II.

N or north point in boss 3inumber of closely spaced lines 42, parallel to the N--S line oi the azimuth scale 40, for a purpose to be described below.

From the foregoing, it will be appreciated that four of the five values mentioned above as being known about the core and its bedding plane,

namely, the apparent direction and apparent degree of dip of a bedding plane, together with the degree and direction of deviation of the axis of the core or the bore hole from a truly vertical position in the earth, can all be represented in the apparatus so far described. The mode of operation to make this representation on the apparatus will now be described.

The point 29 of pointer I1 is set at the de- I the center 43 of protractor 39, thus establishing the longitudinal axis of pointer I! in a truly vertical position. Auxiliary pointer 23 is swung downwardly and placed on the N-S line of azimuth scale. 49, at any convenient distance from center 43, thus also establishing the azimuth protractor 35 on pointer H in the same vertical N--S plane. Screws 2! are tightened to hold pointer I! in the position just described. Assume an apparent strike of N. 61 W. and an apparent dip of 40 to the N. 29 E., as previously determined from. the oriented core by the well known methods mentioned above. The first named value, namely, the apparent strike, may be disregarded in these adjustments, but its related value, the apparent direction of dip, is utilized, as will be explained. The apparent degree of dip, 40, is set oil on protractor 33 by inclining plate 28 to that value. The apparent direction of dip, N. 29 13., is set 011 on azimuth protractor 35 by rotating plate 28 and sleeve 29 about pointer l1 until hand 36 indicates that value. Screws 31 and 33 are then clamped to hold the sleeve and plate in the adjusted re- Assume a deviation of 6 to the N. 60 E. between the core axis and a truly vertical position, determined from a directional survey of the well bore at the time the core was taken. Clamp 2| is moved from its previous position at the center 43 o! protractor 39 and is placed on line N. 60"E. of scale 49, at its intersection with the 6' circle of the concentric deviation degree scale 4|, as shown at point A of Figure 3. Auxiliary pointer 23 is then used to turn pointer I! about point 29 at A, pointer 23 being swung downwardly and placed at any convenient point B on the same N- -S line 42 as that on which point A is located, in order to correct the N-S line of plate 28 to a true N-S position. Clamp screws 21 are tightened to hold pointer H in its adjusted position. Plate 28, representing the bedding plane or stratum, is now in its true position, exactly as it was in the earth before the core or sample was taken.

The problem now remains to determine from plate 23 the true direction and degree of dip, from which the strike may easily be computed. By the definition above, the strike is the direction screws 21 are loosened and the point 29 of pointer of the intersection of plate 28 with a horizontal plane and can be obtained directly by a spirit level, to represent the said horizontal plane. which may be laid in a levelled position along the face of tilted plate 28, and a magnetic compass, to determine the direction of the line of intersection of the plate 28 and the edge of the level. A so-called Brunton' compass or transit, which includes a compass and level in one instrument, will be found convenient. The degree of dip can also be determined by using the same level, held horizontally and at right angles to the face of plate 28, and measuring the included angle by a small portable protractor or the inclinometer scale of a Brunton compass. The direction of dip obviously will be the direction in which the plate 28 slopes downwardly and at right angles to the strike.

In order to facilitate these last named measurements, the alternative indicating structure'supported by arm [2 has been devised, and its construction and mode of operation will now be described. A rod 44 is supported in a truly vertical position at the outer end of arm 12 by hearing 45 and is provided with a clamp screw 46 to hold it up out of the way during the adjustment of the plate 28 and pointer I! just outlined. At the lower end of rod 44 is a knife edge member 41 with its lower sharp edge truly horizontal. This may be used in place of the level just mentioned and can be turned about and fitted to plate 28 in its inclined position to determine the horizontal line which indicates the strike of the bedding plane represented by plate 28. An azimuth protractor 48 is secured to bearing 45, with its NS line in the plane of the main NS axis of the instrument, and a hand or pointer 49, sliding on a spline 50 in rod 44, and in the same plane as knife edge member 41, is adapted to show the true direction or strike of that knife edgewhen the latter is lowered to contact plate 28. A clamp screw 5| is provided for hand 49 to secure it in a desired position on rod 44. A knob or handle 52 at the top of rod 44 facilitates turning and lowering the rod.

Referring now to Figure 2, it will be seen that a vertical movable protractor 53 is provided in the axis of rod 44 at right angles to the plane of knife edge member 67. Protractor 53 is pivoted as at 54, in the plane of member 47 and rod 44, and is provided with a scale 55 which cooperates with index members 56 on rod 44 to show the true degree of dip of plate 28. A clamp screw 57 is provided on rod 44 to secure the protractor 53 in its desired position.

Continuing the description of the operation, after the plate 28 is adjusted about shaft 30 so that the apparent dip is indicated on protractor 33, and plate 28 is rotated about pointer I? so that the apparent directionof dip is indicated on azimuth protractor 35, and pointer I1 is set on scales and-4i and auxiliary pointer 23 is set on parallel scale 42 to indicate the direction and degree of deviation, then the horizontal knife edge 4'! may be lowered by means of rod and rotated about its vertical axis until it exactly fits the inclined plate 28 and thus determines the true strike of the bedding plane. Clamp screw 46 is then tightened on rod it to hold it in position.

The direction of the true strike may be readdirectly from azimuth protractor 48 by lowering hand 49, splined to rod 44, to touch that protractor.

During the fitting of knife edge 4? to plate 28,

the dip protractor 53 is allowed to move freely about pivot 54, and, when the contact is com pleted, and due to the contact surfaces of 41 and 53 being in the same plane, protractor 53 will be found to indicate the true degree of dip of the plane represented by plate 28 on that side of the scale 55 which'reads less than 90 degrees. The true direction of dip may be computed by taking into consideration the downward direction of plane 28, as indicated by that side of protractor 53 which is below the horizontal, and the definition above, that the strike and direction of dip are at right angles or 90 degrees apart. In the example given, which will be briefly repeated, the apparent strike was N. 61 W., and apparent clip was 40 to the N. 29 E. The deviation was given as 6 to the N. 60 E. Using the method and apparatus described, the true strike was found to be N. 72 W. and the true dip 34 to the N. 18 E. The difference between the apparent and true values just mentioned shows the importance and value of the invention.

Although a specific construction and mode of operation have been given as ant illustration of this invention, it is to be understood that the invention is not limited to the specific device and sequence of operation thereof outlined above,

and all such modifications and changes as come.

1. Apparatus of the type described for representing a bore hole and a plane defined by a substratum in the earth intersecting said bore hole, comprising a base, directional orienting means carried by said base, an elongated member supported by said base, said member adapted to be adjustably positioned with regard to said directional orienting means to assume the deviation degree and direction of a bore hole, means carried by said member forming a fiat surface adapted to be positioned with regard to the axis of said member and the directional orienting means of said base. to reproduce the apparent degree and strike or direction of dip of a substratum intersecting said borehole, and means cooperating with said directional orienting means for measuring the true degree and strike or direction of dip of said fiat surface means.

2. Apparatus of the type described comprising a base, inclination and direction orienting means associated with said base, a pointer journalled for universal movement about a point spaced from said base, said pointer adapted to cooperate with said orienting means, and a plane member carried by said pointer, said plane member adapted to be adjustably positioned about the longitudinal axis of said pointer and also adapted to be adjustably inclined at a predetermined angle with regard to the said longitudinal axis of said pointer.

3. Apparatus of the type described, according to claim 2, in which said pointer is provided with means for orienting said pointer in a given plane with respect to said orienting means.

4. Apparatus of the type described, according to claim 2, with the addition of inclination and direction measuring means aligned with said orienting means and adapted to determine the true position of said plane member.

5. Apparatus of the type described comprising a base, inclination and direction orienting means associated with said base, an elongated pointer supported above said base by a universal joint intermediate its ends, the center of said joint being vertically above said base, the lower end of said pointer adapted to be adjustably positioned onsaid orienting means to assume a predetermined degree and direction of inclination with respect to the vertical, a rotatable sleeve on the upper end of said pointer, a plane member movably supported on said sleeve upon an axis at right angles to the longitudinal axis of said pointer, a scale on said pointer for indicating the relative orientation of said sleeve and'said plane member with respect to said pointer and said first named orienting means, and a scale associated with said plane member to indicate the degree of inclination of said plane member with respect to the longitudinal axis of said pointer.

6. Apparatus of the type described, according to claim 5, with the addition of inclination and direction measuring means associated with said orienting means and adapted to be aligned with said plane member to'determine its position.

7. Apparatus of the type described, comprising a base, concentric azimuth and inclination degree scales on said base, an elongated pointer member supported by said base on an axis passing through the center of said first named scales and at right angles thereto, said pointer adapted to be selectively positioned on said scales, a plane member associated with said pointer member, said plane member adapted to be rotatably positioned about the axis of said pointer, a scale for indicating the azimuth position of said plane mem ber with respect to said axis, said plane member also adapted to be inclined about an aids at right angles to theaxis of said pointer and a scale for indicating the degree of inclination of said plane with regard to the axis of said pointer.

8. Apparatus of the type described, according to claim '7, with the addition of inclination and direction indicating means adapted to cooperate with said first named azimuth scale and the 'axis of said pointer member support, said inclination and direction indicating means adapted to be aligned with said plane member to determine its position.

EDWARD D. LYNTON

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