US2426335A - Side wall sampling apparatus - Google Patents

Description

Aug. 26, 1947. T. A. BANNING, JR 2,426,335

SIDE WALL SAMPLING APPARATUS Filed Nov. 8, 1943 5 Sheets-Sheet 1 Aug. 26,1947. 1'. A. BANNING, JR

SIDE: WALL SAMPLING APPARATUS 5 Sheets-Sheet 2 File d Nov. 8, 1943 Aug 26, 1947. 1'. A. BANNING, JR 2,426,335

SIDE WALL SAMPLING APPARATUS Filed Nov. 8. 194: 5 Sheets-Sheet 5- v q InVehTOk':

T A. BANNING, JR

SIDE WALL SAMPLING APPARATUS Filed Nov. 8, 1943 Aug. 26, 1947. g,4'26,335

5 Sheets-Sheet 4 TY9J4.

Aug. 26, 1947. T. A. BANNING, JR

SIDE WALL SAMPLING APPARATUS 'ESheetS-Sheet 5 Filed NOV. 8, 1943 BC I79 v Inve hTo i";- :1. aw

fiatented Aug. 26, 194' UNITED STATES PATENT OFFICE SIDE WALL SAMPLING APPARATUS Thomas A. Banning, J12, Chicago, Ill.

Application November 8, 1943, Serial No. 569,450

(Cl. 255-1A) 13 Claims. 1

This invention concerns itself with methods and means for taking and recovering samples from the side walls of drill holes, and the like; and also certain improvements in electro-logging such drill holes, especially in reference to the taking of such samples. The features of the irrvention have been devised withv particular reference to the conditions existing in the drill holes of deep wells, but it will presently appear that certain of said features are not limited to use in connection with such drill holes, and are of gencral applicability to tests in drill holes.

At the outset it may be noted that in deep well rilling it is frequently the practise to heed the well with liquid or soft mud or the like, in order toseal off the well against the gas and other pressures found at different strata; although in some cases such flooding is not or may not be resorted to. Still, when such flooding is used there exist very high fluid pressures in the lower reaches of the drill hole, up to five or ten thousand pounds per square inch. .It is a feature of the present invention that the same may be used with full benefit either in drill holes. which are thus flooded or not.

A further feature ofthe invention relates to the provision-of a method and means for taking the samples from the side walls of the drill hole at exactlythe Dre-selected elevation. or location, or strata Which-it is desired to examine in detail. In this connection it is to be noted that in deep holes, of the order of ten thousand feet or more, the stretch of the cable let down in the hole will be such that, without pare-calibration of said cable, or resort to other special means or functions, the instrument or device carried by the lower end of such cable may vary substantially from the estimated location thereof. As a consequencethe samples may be taken from other than the intended location; and in the case of strata which are relatively thin it may be found that the samples have beentalien from some other than the intended strata. An important feature of my present invention relates to the provision of means and method wherebythe indication of position or location of the test device or the sampling head may be very exactly givenwithout reference to the measurement of the amount of cable let down into the hole.

In connection. with the foregoing it is a feature of my'present invention that I have provided method and means whereby the exact location of the sampling head may be known at all times by reference to an electro -logging sheet or curve,

taken either during a previous operation, or during the same operation as-that in which the side Wall samples are being taken. In this connection I may here mention that there ar in extensive use at this time various Schemes of electrologging, some of which incorporate the feature of plotting or taking curves indicative of the oi-lor other bearing-strata; and one feature of my present invention concerns itself with the relating or combiningof such electro-logging operation, of whatever type, with the side-wall sampling operation, so that the exact positioning of the sampling head willbe assured by reference to the electro-log ging indication.

In connection with the foregoing it is also here noted that in certain electro logging operations use is made ofmulti-conductor cables, carrying several-conductors whichare selectively used dur ing the plotting of the, several curves of the electro-log. It is afeature of my invention that I have provided side wall sampling units which may be joined or used together in as great a number of suchunits as. desired, and that I have made provision for operating said units either selectively or simultaneously to take their several samples. It is a further feature of the present invention that these units, or certain of them, may also be used as the electrodes, or may carry the electrodes, used in the electric-logging or indicatinsoperations. I have 50 arranged the parts that the same conductors in the cable may be used selectively forthe electro-logging or indicating operations, and also for actuating the several sampling units for sampling operations, thereby greatly simplifying the scheme, while retaining allthe advantages of both the electro-logging or indicating features, and the sampling features.

A further feature of the invention relates to the side-wall sampling. unit itself. In this connection I have provided means for taking a sample of substantial size, and for retainingsaid sampl effectively and bringing it to. the surface when the device is raised. In this connection it'is noted that certain of the strata to be sampled may be of considerable hardness and denseness; others of greater porosity or softness; some dry; others very wet. I have provided asampling head in the form of a cutter which is capable of drilling itself intothe wall of the bore hole, and retaining the cored out material effectively within itself. In this, connection I have provided for giving to said cutter head rotary as well as translatcry motion during the cutting or sampling operation, and I have-also provideda cutter head of such form that itw-ill-effectively cut or core out a sample of substantial size durin the projecting op eration during which said cutter head is being driven into the wall of the bore hole. I have also made provision for subsequently withdrawing said cutter head from the side wall back into the unit of which it constitutes a part, so that after the sampling operation has been performed said cutter head will not remain projecting beyond the confines of the unit proper. This will make it possible to withdraw said unit to the surface without interference from the walls of the bore hole, which are rough and uneven, and of varying separation. I have also made provision for effecting such withdrawing operation in such manner that the already cut-out material of the sample will not be screwed out from such sam pling or cutting head, but will be retained therein. In this connection, sometimes I effect the retraction or withdrawing of the cutter head without any rotation thereof (it having been rotated during the projecting and cutting operation) and sometimes I effect such withdrawal or retraction, first without rotation, and afterwards with rotation, all as will presently appear hereinafter.

In connection with the foregoing, it is here noted that when the cutter head is forced into the wall of the bore hole with a rotary cutting operation, accompanied with translatory movement, during the final stages of such movement some portions of the material of the wall may remain joined to the wall, either solidly or by reason of jagged or other projections, so that it is desirable to commence the withdrawal movement directly, and without rotation of the cutter head; and it is an object of the present invention to make provision for obtaining such result.

A further feature of the invention relates to the provision of means whereby a very considerable penetration of the cutter head into the wall of the bore hole will be assured. It is noted that generally there exists a layer of hard mud or the like on the surface of the bore hole, and which must be penetrated before the cutter head begins to penetrate the native strata. This mud layer may be from one-fourth to three-fourths inch thick; so this movement of the cutter head is ineffective to take a sample of the native rock. Furthermore, the reaction of the cutter head against the rock must be balanced by contact of the sampling device against the wall of the bore hole opposite to the side being sampled, and the movement of the sampling device laterally to make such contact must be effected prior to commencement of actual sampling.

It is a feature of the present invention that I have made provision for ensuring a large movement of the cutter head in the direction of its working stroke. Sometimes I secure this movement by power actuating means working directly transversely of the device; and sometimes I secure such movement by power actuating means working lengthwise of the devicethat is, parallel to the axis of the bore hole, vertically. In each case, however, I employ power actuating means embodying features of the present invention.

Provision must be made for exercise of large forces to ensure penetrating and cutting of the hard material of the wall of the bore hole. It is a feature of my present invention that I make use of combustible, carried internally in the sampling device or unit itself, generally in the form of explosive. Such combustible is capable of generating large amounts of kinetic energy per unit weight; but presents the disadvantage that the rate of combustion is high so that heretofore it has been the practice to take the samples (when using explosive as the power generating means) by a sampling operation in which a hollow or chambered projectile has been shot against the 'wall of the bore hole at high velocity, but not under control from the sampling device or unit itself, beyond delivering to the projectile such high velocity. According to one feature of my present invention I provide means for generating a, large amount of static energy of pressure of a fluid by use of the combustion of the explosive; and I then provide means for releasing this static energy of pressure at a relatively slow rate to the cutter head, so that said cutter head is forced into the wall of the bore hole at a relatively slow rate, but under great force. In this connection I have so arranged the parts that the rate of such energy release may be pro-adjusted in very simple manner, so that satisfactory operation is ensured according to the conditions of the operation. Such pre-adjustment may also take account of the-size of the combustible charge being used.

In connection with the foregoing feature I preferably make use of a substantially non-compressib-le liquid as the force delivering medium for delivering pressure to the plunger which actuates the cutter head, said liquid being a suitable wax free oil or the like. I place a piston or plunger between the high pressure gas generated by the combustion operation and said liquid, thereby isolating these two fluids from each other.

I have provided means for retracting the cutter head after lapse of a suitable time interval. This means generally takes the form of a strong retracting spring or springs; and in this connection I have so arranged the parts that a very large movement of such spring or springs may be provided for within a relatively small space or length by proper relative positioning of the components of the retracting spring unit.

During retraction of the cutter head after the sampling out has been made it is necessary to release the fluid pressure previously used for the cutting operation. I have therefore made provision for such release of pressure by release of gas from the combustion chamber. In this connection it is to be noted that such gas pressure release should occur after lapse of sufficient time to ensure proper cutting and sampling operation; and furthermore, that the gas so released must be permitted to escape into the bore hole. This means that there must be an opening from the gas pressure chamber of the sampling device to the bore hole during gas release. It is also noted that when sampling is to be effected within a bore hole which is flooded with mud, there exists a high hydro-static pressure around the sampling device, and that without special provision in the construction of the sampling device this pressure would cause entrance of mud or other liquids into the interior of the sampling device.

It is a further feature of my present invention that I have made provision for sealing the combustion and other chambers of the sampling device against entrance of mud or other liquids thereinto prior to the time when the gas is to be allowed to escape after the sampling operation has been completed; and that I have secured this result in a very simple device and without the use of valves or other parts which would be objectionable for use under the conditions existing in service of such a sampler.

. A further feature of the present invention relates to the provision of an arrangement such that two or more of the sampling units may be greases connected together and raised or lowered in the borehole simultaneously by the use of a single cable. In this connection it is an object of the invention to so arrange the parts that when these units are connected together the several electrical lines for the electro-logging and sampling operations will be properly connected to each other from unit to unit. In this connection it is a further object to so arrange the parts that such connections from unit to unit will be effected in sealed chambers and with complete isolation of the connections from the material in the bore hole, be such material gas or mud or other liquid.

In connection with the foregoing it is a further object to so arrange the parts that the various sampling units maybe joined together in any desired sequence, and still ensure proper interconnectionof the circuits of the various units to each other, and without special connections having. to be made by the operator.

A further feature of the invention relates to the construction of the sampling unit per se. In this connection it is an object to provide a. construction of such sampling unit which may 'be constructed in very rugged form, and well adapted to withstand and resist the large forces to which it will be subjected in service. Also, to so arrange the parts that these parts may be readily assembled or taken apart for cleaning or repair from time to time. It is noted that certain parts, such as'the sampling or cutting head are subject to relatively rapid wear due to the very nature of the work they are called on to perform; and I have made provision for replacement of such parts without difiiculty and without having to take down the entire unit. In this connection, also, I have made provision for easily opening the sampling chamber within which the sample is received during the sampling operation, so that said sample maybe readily removed from such chamber after the device has been brought to the surface.

'Other objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

In the drawings:

Figure 1 shows a Vertical section through a typical sampling unit or device embodying features of my present invention, and in whichthe plunger for actuating the cutter head works in a direction transverse to the axis of the borehole;' and in which'provision is made for rotary movement of the cutter head during the projecting'stroke, with non-rotation during the retracting stroke; and is a section on the lines I--l of Figures 2 to 12, inclusive, looking in the directions of the arrows;

Figure 2 is a horizontal section on the line 2-2 of Figure 1,looking in the direction of the arrows, and through the combustion chamber;

Figure 3 is a horizontal section on the line 3-3 of Figure 1, looking in the direction of the arrows, and through the oil or liquid chamber, showing the plunger therein which separates the gases of combustion from said oil or other liquid;

Figure 4 shows a horizontal section on the line i-d of Figure 1, looking in the direction of the arrows, and throughthe cutter head actuating plunger and control parts, said parts being retracted to their normal position, and provision being made for rotation of the cutter head during projection thereof in the working stroke, and for retaining said cutter head against rotation during the-retracting stroke; and Figure 4 may also be considered as a section on the lines 4-4 of Figures 5, 8,9, 10, 11 and 12, looking in the direction of the arrows;

Figure 5 is a fragmentary sectionor viewlooking at theoutside of the unit and towards the cutter head thereof;

Figure 6 is a top or plan View of the unit;

Figure 7 is a bottom or inverted view of the unit;

Figure 8 is a fragmentary section on the line l-3 of Figure 1, looking in the direction of the arrows, and towards the-inner end of theplunger element;

Figure 9 is a fragmentary section on the line 9-9 of Figure 1, looking in thedirection of the arrows, and through the clutch elements for ensuring forward rotation of the cutter head during the projecting or working stroke;

Figure 10 is a fragmentary section also through the said clutch elements but taken on the line lii--Etl of Figure 1, and looking in the direction of the arrows, opposite to the section of Figure 9;

Figure 11 is a fragmentary section on the line l !--l I of Figure 1, looking in the direction of the arrows, and through the clutch elements for retaining the cutter head against rotation during the retracting stroke;

Figure 12 is a fragmentary section also through the said clutch elements but taken on the line l2-l2 of Figure l, and looking in the direction of the arrows, opposite to the section of Figure 11;

Figure 13 is a fragmentary cylindrical section on the line iii-43 of Figure 1, looking in the direction of the arrows, and showing in plan View the plunger assembly and cutter head thereon;

Figure la is a fragmentary cylindrical section on thelline l l-M of Figure 1, looking in the direction of the arrows, and showing in plan view the clutch assembly with the plunger assembly therein;

Figure 1.5 is a fragmentaryhorizontal section on the line I 5-i5 of Figure 1, looking in the direction of the arrows, and showing in inverted view the inner faces of certain of the clutch elements;

Figure '16 is a fragmentary section similar to that of Figure 1, but showing a modified form of the plunger and clutch elements whereby during projection of the plunger during the working stroke the cutter head is first advanced without rotation, and then with rotation in the cutting direction; and whereby during the retracting stroke the cutter head is first withdrawn without rotation, and then with rotation in reverse direction;

Figure l? is a Vertical section on the line l'l-l l of Figure 16, looking in the direction of the arrows;

Figures 1, 5, 8, and 9 to 17, inclusive are on sub stantially full scale, and Figures 2, 3, 4, 6 and '7 are on substantially one-half scale;

Figure 18 shows, more or less schematically another modified arrangement embodyin features of my present invention, and in which the plunger is arranged for movement axially of the unit insteadof transversely thereof, and with provision for a greater amount of movement thereof than in the previously described arrangements; the cutter headmovin transversely of the unit and directly towards the wall of the bore hole; the combustion and transfer chambers also being placed vertically in the unit;

Figure l9 shows a fragmentary-view of aportion of the double coiled spring drive from the in the wall of the bore hole without need of raising the units to the surface, the cable wires being used selectively for either 01' both the electrologging and side wall sampling operations;

Figure 2.1 shows a section of the strip of curves of the electro-logging test which shows the geophysical conditions of various strata throughwhich the bore hole penetrates; and

Figure 22 shows how such a set of curves as that of Figure 21 may be used for giving an exact indication-by use of features of my present invention, to show the exact point at which it is desired to take side wall samples, and for securing such samples at such point or points with exactness :and certainty.

In a practical embodiment of features of my present invention I prefer to provide a side wall sampling unit for each sample to be taken during a test operation, and when it is desired to take more than a single sample I arranged to couple together a number of these units equal to the number of test samples to be taken (or greater than such number) lowering and raising all these units together in the drill hole by a single cable. Preferably, also, these units are all controlled by electrical conductors contained in said cable, and properly interconnected at the lower and upper ends of the cable, or bore hole. Furthermore, when features of electro-logging are to be embodied in the same test or series of tests in which use is to be made of the units for side wall sampling purposes, I prefer to provide such units of such form so that they, or portions of them may also serve as the electrodes necessary during the electro-logging operations. Such a type of unit is shown in Figures 1 to 15, inclusive, and modifications thereof in Figures 16 and 1'7, and in Figures 18 and 19; but I shall first describe the arrangement of Figures 1 to 15, inclusive.

Referring first to Figure 1, I provide a unit designated in its entirety by the numeral 25. It preferably comprises a generally cylindrical metal body 28 of diameter somewhat less than the diameter of the bore hole. The upper end of such body is preferably provided with a male connector element 21, in the form of a tapered threaded nipple; and the lower end of such body is preferably provided with a female connector element in the form of a threaded socket member 23; and these male and female elements are of companion sizes and threads so that any unit of a series may be readily threaded and joined to other similar units above and below it. This feature will be further considered hereinafter.

Within this body member I provide a combustion chamber 28, to receive the charge 30 of propellant, generally slow burning powder or explosive. In this connection the use of nitro-cellulose propellant of granular form will be found advantageous, the size of the granules being selected for relatively slow combustion. Further more, the density of loading should be selected to produce high pressures, say of the order of twenty to thirty thousand pounds per square inch, but not excessive pressures. The combustion chamber 29 is reached from each end by removal of the plugs 3| and 32 in the body of the unit. Preferably, also, one electrod 33 is grounded to the body of the unit, whereas the other electrode 34 is carried by an insulating ring 35, said grounded electrode and said insulating ring being gripped in place by the plugs 32 and 3|, respectively. These electrodes are of spring quality so that they will contact against the terminals 36 and 31' of the fusible link 38 passing through the propellant charge 30, to thereby fire said charge when current is passed between the electrodes 33 and 34.

There is another cylindrical or free piston chamber 39 in the body ofthe unit; and a movable free piston or partition 48 in the form of a plug or plunger is slidably placed therein. A port t! establishes communication between the combustion chamber 2% and the chamber 39, so that the gas pressure existing in the combustion chamber is communicated to the proximate face of this partition or plug 30. Preferably a piston ring 42 is provided on this plug 49; and also the gas pressure face thereof is preferably protected by a layer of heat insulating, pressure resisting material 43, such as compressed asbestos or other composition material.

At the end of the chamber 39 opposite to the ported end M there is provided a partition 44, with a shoulder 15 to limit the approaching movement of the plug 46; and a port 46 is provided in this partition fi l. Beyond the partition 44 the body of the unit is provided with a passage 41 which reaches to a position where it will communicate with the working face of the cutter driving plunger. This plunger is designated in its entirety by the numeral 48, and the details of construction thereof will be considered hereinafter.

The chamber 39, port 46, and passage 41, and directly connected passages are filled with noncompressible liquid, such as Wax free oil capable of resisting the pressures and temperatures to which it will be subjected; or other suitable liquid may be used therein. Preferably a stop abutment 49 is provided for limiting the backward or returning movement of the plug 40. It is here noted that the cutter driving plunger 58 is normally retracted to its returned position by a spring member 58, the details of which will be presently considered, so that under these conditions the plug 40 is normally restored to the position shown in Figure 1.

Upon firing the charge of combustible, 30, gas pressure will be built up in the combustion chamber and against the plug 43, and said plug will be subjected to pressure tending to drive it towards the port 46. This will place the liquid in the chamber 39, and passage ll, etc., under pressure, and the plunger element 43 will be subjected to a force tending to move it in the projecting position or direction. Such movement will require that the force of the spring element 50 be overcome, but said spring, while strong enough to return the parts to their initial position, as hereinafter explained, is not strong enough to exert more than a fraction of the force exerted by the hydrostatic pressure against the plug 48. For example, if a gas pressure of 30,000 #/sq. in., be generated, and the effective area of the plunger' l be assumed as 1 /2 sq. in., there will be exerted a pressure against the working face of the plunger equal to 45,000 and if the sprin element, 50, in its fully extended condition exerts 9 a force of 500#, there will still be available a force of 44,500#'against the plunger.

Now, because of the fact that the rate of combustion is relatively high (for example, of the order of /100 sec.) being of explosive nature, and since it is desired to project the plunger element 48 with a relatively slow movement (for example, within a time interval of, say 1-2 secs), is isdesired toprovide means to control the transfer of energy from the combustion chamber to the working face of the plunger element 48. Such control means I have provided in the form of the port 46 in the partition 44. This port is conveniently formed in a metering plug 5| screwed into the partition A l; and this metering plug may be selected with a port of size according to the rate at which liquid flow from the chambe 39 through the passage 41, and against the plunger A8 is desired. By selecting a metering plug with a smaller port, the rate may be reduced, and the time required for complete cutting projection may be increased; or vice versa. It will be noted, however, that whenever the cutter head encounters an obstruction or material requiring the use of increased force for continuation of the projecting movement, the hydro-static pressure behind the plunger element will buildup to whatever amount is needed to continue the projecting movement of the plunger and cutter head, within the limits of pressure available from the combination chamber,

It is further to be noted that in case of firing the combustible charge under conditions when the cutter head does not encounter resistance, or encounters relatively small resistance, the rate at which the plunger element and cutter head will be projected will be limited by the flow of liquid through the metering port, so that damage to the plunger and connected parts will be avoided, and

so that in case such plunger and cutter head movement should continue, without substantial resistance, to the full end of the working stroke, the arresting of such movement will not result in damage to the parts.

As a matter of convenience in construction, the bodj of the device may be provided with removable plugs 52 and 53 in line with the chamber 39; the stop abutment 49 being provided on the plug 52, and the plug 53 giving access to the metering plug 5! for replacement or adjustment thereof. Furthermore, the plug 53 may, if desired, be provided with a filler plug 54, which, when removed, exposes a filler port 55 in the plug 53, through which liquid may be readily inserted to refill or replace the liquid within the chamber 39 and connected parts.

Now it must be noted that after combustion has been effected with generation of gas with the chamber 29 and connected parts, the pressure therein Will remain at a high value, even after the movement of the plunger 48 has been completed in the projecting direction. Furthermore, without gas release this condition might continue for an indefinite interval of time I have therefore made provision for release of gas pressure. For this purpose I provide a leakage port 56 in communication with the combustion chamber, said leakage port preferably being formed in the plug 32. Furthermore, preferably a small plug 5! is removably screwed into the plug 32, said plug 51 being provided with the leakage port, and the plug '32 being provided Witha larger passage 58 with which said leakage por-t communicates. By selection of a plug 51 having a properly sized leakage :port it is possible to secure leakage-at 'a rate which will ensure retention of internal pressures within thedevice for a sufficient length of time to ensure complete projection of the plunger lfl-andicutter head, against the forces being encountered, and at the same time to permit lowering of the internal pressures sufiiciently after a relatively short interval of time, 'for ex-' ample, thirty seconds, to allow the spring element to retract the connected parts after such interval oftime.

The leakage port 56 will generally be of small size, but nevertheless while said ,port is open it gives communication between the interior and exterior of the unit. In case of lowering of such unit into a 'bore hole which is flooded, or wherein liquids are present under pressure, it would occur that such liquids would be forced through the leakage port and into *the'combustion chamber and connected parts, with consequent objectionable or serious results. I have therefore made provision for normally closing this -leakage port in gas and liquid tight manner until the leakage is to commence. For this purpose I provide a, blow out or fusible seal 59 at the outer end of the leakage :port, said seal serving to prevent inflow of liquids from the bore hole under any pressures which may be found in the bore hole; but when combustion takes place in the chamber 29, thereby generating temperatures of upwards of four to five thousand degrees F., or more, and at pressures of upwards of twenty to thirty thousands of pounds per square inch, or more, said seal will be either fused or blown bodily out from theend of the leakage port, and leakage will then commence outwardly through said port,

and will continue until the internal and external pressures reach a condition of balance. the sampling unit has been raised to the surface When the plug 51 may be removed and another sealed plug substituted therefor prior to the next sam- *plingoperation by such unit.

is threaded into the front or outer end of the assembly as shown.

The entire plunger assembly is received within a transversely extending bore or cylindrical opening of the body of the device; and preferably a large plug is provided at the back end of this bore. The rear end of the plunger assembly is provided with a removable ring or flange member 66, connected to the plunger body by a series of screws; and this ring or flange member has the inwardly reaching flange 51 which constitutes an abutment for one end of the retracting spring. Said retracting spring comprises the external and internal spring elements 63 and 69, respectively, the external element being normally an open spiral, and the internal element being normally a tightly closed spiral. The outer end of the outer element bears against the inner face of the flange 61; the inner ends of both the inner and outer spring elements are connected together by a plate 10, the inner end of the outer spring element bearing against the edge of said plate Hi and the inner end of the inner spring element 69 being connected to the center of said plate; and the outer end of the inner spring element 69 is passed through a hole of the plug 65 and receives a nut or nuts H to retain said spring element against pull from the plug 65. The plug 65 is provided with a recess or socket 12 wherein said nuts are contained; and a sealing plug 13 is provided for closing this socket in gas and liquid tight manner.

With the foregoing scheme it will be seen that outward movement of the plunger assembly will cause compression of the spring element 68 and stretch of the spring element 69, so that a double amount of movement of the plunger and cutter head is provided for, and at the same time prings of relatively large wire and great strength may be used within a relatively small spring chamber, and with use of a spring chamber of relatively short length for the required amount of plunger movement.

The plunger element 60 is externally threaded with one or more threads or grooves 14 (eight in the form shown), and these threads are of selected pitch depending on the desired rotation of the cutter head during the cutting operation. There is a ring '15 placed around the plunger element 6!], said ring having splines 16 to correspond with the threads or grooves of the element 60, so that proper co-operation is ensured between the element 60 and said ring. Said ring 75 is placed within a recess or circular opening 11 formed in a removable nut element 18 which is in turn threaded into a socket or circular opening in the body of the sampling unit. Said nut element has the inwardly reaching flange 79 which serves as an abutment against which the outer end or edge of the ring 15 will bear to prevent outward movement thereof; and preferably an abutment ring 80 is threaded into the inner end of the socket of the body of the unit, the inner end of the ring 15 bearing thereagainst. Thus said ring I is retained against endwise movement in either direction, but is permitted rotary Or rocking movement with respect to the body of the device, It is noted that this ring 15 is placed adjacent to the outer end portion of the plunger element so that rotary control of the plunger element is assured 1 for full stroke thereof outwardly, or in the working or projecting direction.

Around the rear portion of the plunger element 68 there is placed a rotatable cylinder like member 83*, same being accommodated in a cylindrical recess of the body of the device. This element 80 has on its inner face a series of longitudinally extending grooves or slots 8| into which there work teeth or lugs 82 carried by the flange member 66, already referred to, so that back and forth movements of the plunger element occur without back and forth movements of the cylindrical element 80 but any rotary movement of the element 63 will be accompanied b similar rotary movement of the cylindrical element 80 Said cylindrical element is accommodated within a suitable recess of the body member and behind the ring 80, already referred to, so that endwise forces of the ring 15 are not communicated to said cylindrical member 89 The ring 15 is provided with an outwardly extending flange 83 having the clutch teeth 84 (see Figure 14); and a clutch ring 85 is located in the circular opening Ti, and is provided With a series of slots 86 which engage flanges 81 of the ring or nut element 18, so that said clutch ring 85 cannot rotate but can have back and forth movement during over-running movements. Suitable springs 88 retain the ring clutch 12 element normally in engagement with the clutch ring 83. The teeth 89 of the clutch ring engage the teeth 84 of the ring 15 to lock against relative movement in one direction, but permit over-running in the other direction.

The design illustrated is such that during the working or projecting stroke the cutter assembly will be rotated counter-clockwise when looking at the outside end of said cutter head (as in Figure 5). The threads or grooves 14 and the splines 16 are correspondingly formed; and it is here noted that the nut element 18 should be provided with right hand or regular threading so that it will tend to lock tight under the forces now to be explained.

Upon exertion of pressure against the working face of the plunger element said element is moved outwardly, that is, towards the left in Figure 1. Such movement tends to rotate the ring element 15 in a clockwise direction (viewed as in Figure 5), but such rotary movement is resisted by the engagement of the clutch teeth 84 and 89 with each other; and due to the non-rotatin of the ring 85 the ring I5 is also prevented from rotating backwardly, or clockwise. As a conse quence, during the outward or projecting stroke the plunger element is compelled to rotate counter-clock-wise, and the rotary force exerted on the nut element 18 tends to lock said element more tightly into place, due to the direction of its threading.

It is now noted that during retracting or returning movement of the plunger element, un-

der impulse of the spring assembly, either of two movements of the parts might occur. If the plunger assembly and cutter head should be retained against backward or clock-Wise rotation (viewed as in Fig. 5), the ring 15 would be compelled to rotate in a counter-clock-wise direction (viewed as in Figure 5), and such rotation is permitted by reason of the form of the clutch elements so far described. On the other hand, if said ring 15 should be retained against clock-wise rotation (viewed as in Figure 5), the plunger assembly and cutter head would be compelled to rotate backwardly during the retracting movement thereof (that is, clock-wise when viewed as in Figure 5); and a further or intermediate condition may be obtained, as will presently appear.

Around the cylindrical element 83 there is placed a clutch ring 9!], which is splined to said cylindrical element 80 by the splines 9|, springs 92 being placed between the parts so that said clutch ring is normally forced to the right in Figures 1 and 14; and so that said clutch ring must rotate with the cylindrical element 8!). There is a companion clutch ring 93 set into the body of the unit around the cylindrical element 89 and adjacent to the clutch ring 90, and locked against rotation by the studs 94 (see Figs. 14 and 1). The clutch rings and 93 have the companion teeth 95 and 96 which face in such directions that the cylindrical element 80 may rotate with over-running of said teeth for counter-clock-wise rotation (viewed as in Figure 5), but so that looking will occur against clock-wise rotation.

It has already been explained that the plunger element and the cylindrical element 80 are splined together so that they must rotate together, but so that longitudinal movement of the plunger element is provided for. The following operations are now evident: During outward projection or working strok movement of the plunger element and cutter-head, with rotation thereof counter-clock-wise (viewed as in Figure the clutch ring Sill will be rotated counter-clock-wise also, the clutch teeth over-running; but during the return or spring retracted movement the clutch rings 98 and at will prevent any clock-Wise rotation of the plunger element and cutter head, the clutch elements 83 and 85 now over-running and permitting the return movement of the cutter head without rotation. In other words, during the outward or working projection movement of the cutter head, same is compelled to rotate counter-clock-wise for the cutting operation, but during the return movement said cutter head is retained against movement of rotary nature. On each outward or Working stroke said cutter head rotates counter-clock-wise, and on each return or spring drawn stroke said cutter head does not rotate.

The cutter head proper, at, is in the form of a ring of hard metal til, the rear edge portion of which is threaded into the body fill of the plunger assembly, preferably by a right .hand thread so that during the cutting operation said cutter head tends to look more tightly to the said body. Said ring is provided with cuttin teeth .98, so that during the cutting projection movement these teeth will cut a circular groove in the face of the bore hole as the penetration continues due to the continued projection of the cutter head. Said cutter head also includes the inwardly extending cutter blades or laws 99, preferably four in number. Each of these is integrall connected to the ring by a broad juncture, sec, and each blade then tapers to a relatively narrow inner or central portion ldl. These inner or central portions lili are also extended forwardly or in the direction of cutting projection, so that said inner ends contact the face of the bore hole prior to the more outwardly or greater radius portions of said jaws or blades. Furthermore, each blade or jaw is separated from the adjacent ones to provide the spaces H52 between said blades, and through which the out off material may readily pass to the interior or sampling chamber 52. Furthermore, each of these blades is formed with its leading or cutting edge i553 more advanced than its trailing or leaving edge ltd, so that penetration of the blades into the wall of the bore hole is more readily accomplished. Such drag of these cutting blades may be made quite con siderable, as shown, or even greater if desired.

With this form of cutter head it will be evident that as the same is forced outwardly into contact with the hard material of the bore hole, and under a great but relatively slow hydraulic force, a circular groove will be cut into the face of the Wall of the bore hole, and the material Within said ring will also be cut or sheared off by the blades, and all said material will pass backwardly between the blades and into the chamber 62 Where it will collect. Since the retracting movement of the plunger assembly is performed without backward rotation thereof (in the form so far described) it will be seen that there will be little or no tendency for such so-collected material to again move out of the sampling chamber 62, but said material will be effectively retained therein. Sometimes it may be found advantageous to provide the spiral teeth Hi5 on the cylindrical surface of the chamber 62, same spiraling in the direction of rotation during working projection of the plunger assembly; and these teeth, when provided, preferably have easy advancing .or leading edges, so that the incoming material will .be

14 permitted to slide over them with ease; and preferably have sharp back or leaving edges, as shown, so that during the retraction of the cutter head and plunger assembly after the cutting operation has been completed the material will be more effectively retained Within the sampling chamber 62.

It should be here noted that with the foregoing arrangements after the projecting and cutting operation has been completed, there may remain portions of rock or other native material which have been loosened by the cutting ring and the blades, but which still retain connection with the native deposit. By direct retraction of the cutter head assembly bachwardly without rotation thereof, such portions of material will be drawn back with the cutter head either by the blades 99, or by the engagement of the teeth IE5, or both; so that such portions of material will be completely broken off from the native deposit, and will be taken and retained in the sampling chamber 62, and brought to the surface when the unit is raised.

It is also noted that with the arrangements so far described, after the sampling unit has been brought to the surface the cutter head may be readily unscrewed from the assembly by use of a simple tool such as a spanner wrench engaging the teeth or blades and with a counter-clock-wise rotation of the cutter head.

Now it is noted that during the working projection of the plunger element the teeth 82 sweep along the grooves 8i and cause a displacement of liquid in said grooves; and I have made provision for drainage thereof by the holes its, formed in the flanged plate ill in alignment with the said grooves. Likewise these holes will provide for relief of liquid material from or to the spiral grooves 845 since these are in direct communication with said grooves 8i. Also, during back and forth movements of the plunger element it is necessary to provide for drainage of the spiral grooves M in advance of the teeth it of the ring l5. For this purpose I provide a circular channel H3! in the plunger element directly behind the ring 97 of the cutter head; and in the forwardly extending portion of the ring it I provide a series of openings Hi8, so that, prior to the time when the cutter head has been projected beyond said ring 15 there may be circulation of material between the channel Hill (and spiral grooves), and the space Within the nut element M. I then provide a series of openings H39 in the front face of the flange l9 of said nut element, thereby providing communication to the exterior of the device. These openings I09 may also be used for turning the nut element by a suitable spanner wrench when necessary.

It is evident that the efiective area of the plunger is substantially proportional to the "diameter of the member ill measured to the bot-- tom of the spiral groove M- thereof, since said grooves are in communication with the high pressure side of the hydraulic system; but in the form shown this effective area also includes the crosssection of the plunger element 60 between said spiral grooves, and equals substantially 1.89 so. in. Under a differential of pressure between the interior of the device and its exterior, or, say, thirty thousand pounds per square inch, there might be exerted a driving force of as much as 44,000 pounds to force the cutter head outwardly and cause rotation thereof, said force being eX- erted gradually and under control, as determined .by the size of the metering port 46.

It is noted that any leakage of oil or other drivingliquid will be past the teeth 15 and through the grooves i l of the element 56, and thence to the outside of the device. Such leakage will sweep any foreign matter outwardly, thereby keeping the moving parts well lubricated, and preventing entrance of mud and other gritty matter into the moving parts. After retraction of the sampling unit to the surface, any oil or other liquid which has been lost by leakage or otherwise may be replaced by removal of the plug 543 and introduction of supplemental liquid through the opening 55, the plunger assembly, and the partition 42 being in their restored positions.

In Figure 16 and 17 I have shown a modified arrangement or plunger assembly of simpler form than that heretofore shown and described. In this modified arrangement the outward of cutting projection of the cutter head is first performed with-lout rotation, and during the remainder of such pojection rotation is caused in the cutting direction (counter-clock-wise when viewed as in Figure It is noted that a certain amount of such preliminary projection may be performed without such rotation, since it is necessary to first cause such an amount of movement of the plunger assembly as will cause the sampling unit to set solidly against the face of the bore hole opposite to that which is to be sampled, and it is further necessary to cause the cutter head to penetrate the caked material on the wall of the bore hole prior to encountering the native rock. Such caked material is relatively soft and does not require the use of a rotary motion to cause cutting penetration thereof. All such preliminary movement of the cutter head may therefore be accommodated without rotation of the cutter head, such rotation commencing afterwards, and when the hard native rock material has been encountered.

This arrangement of Figures 16 and 17 is also such that during the first portion of the retraction or restoring movement of the plunger assembly, there is no rotation of the cutter head, but

thereafter rotation takes place backwardly, or clockwise. In this connection it is noted that such first portion of the retraction of the cutter head should be without rotation so as to make sure that the loosened or disengaged sample portions will be retained within the sampling chamher, and will be effectively disengaged from the native strata, and this result is ensured by causing the first portion of the retraction to take place without rotation. The remaining retraction may then occur with rotation in either direction without danger of loss of the sampled material out of the sampling chamber.

The arrangement of Figures 16 and 17 is similar to that already described; but in the present case the ring 75 having the teeth 76 which ongage the spiral grooves 'M is permitted to rock back and forth through an angular distance or swing sufficient to permit the desired amount of longitudinal movement of the cutter head without rotation. For this purpose said ring 75* is provided with the two lugs H0 which work be tween inwardly extending lugs ll! of the nut element 78*. Also, the cylindrical member 80 with the longitudinally extending grooves 8i has been eliminated, and also the teeth 82 of the flange member 48 have been eliminated. In place thereof said flange member 48 is provided with the outwardly reaching portion 82 travelling in the cylindrical opening Bl of the body of 16 the unit, suitable drain holes being provided in said flange portion 82 as in the previously described arrangement (see Fig. 8).

It will now be evident that the following operations may occur;

When plunger movement commences the ring member 15 will rotate backwardly (clock-wise Viewed as in Figure 5*) until the lugs I It engage the far lugs I I I, whereupon such movement will be arrested, and further outward projection of the plunger element will require rotation thereof, with rotation of the cutter head, in counterclock-wise direction until completion of the projecting movement. This will satisfy the rotational requirements heretofore mentioned. When, thereafter, retraction of the plunger element commences, the first portion of such retraction will occur with rotation of the ring T5 counter-clock-wise until the lugs Ill] engage the far lugs Ill, during which interval there will be no rotation of the plunger element and cutter head, same being withdrawn during this interval with a direct movement. Thereafter the further retraction will occur with rotation of the cutter head clock-wise; but such direction of rotation will not be objectionable since the sample material will have been effectively torn from the wall of the bore hole during the previous non-rotational movement of retraction.

It is also noted that with the arrangement of Figures 16 and 17 the teeth I65 on the wall of the sampling chamber 62 may be spiralled against the rotation of the unit during retraction, so that the sample material within the chamber will not tend to work out from said chamber.

It is noted that with the arrangement of Figures 16 and 17 the clutches have been eliminated with corresponding simplification of the structure.

Now the projecting travel possible with such arrangements as shown in Figures 1 to 17, inclusive, is limited by the diameter of the sampling unit, which in turn is limited by the diameter of the bore hole itself. I shall now describe a scheme embodying features of my present invention, and wherein the projecting movement suffers no such limitation. This scheme is shown more or less simply in Figures 18 and 19. In this case the combustion chamber H2 is placed vertically or axially of the sampling unit, and the transfer chamber 1 I3 is placed directly above said combustion chamber, so that the partition element H4 moves up and down. The metering port I I5 is placed in the partition H6 above said transfer chamber; and the plug H1 in the top of the unit may be removed to gain access to the interior of the device, the plug I [8 giving access to the combustion chamber. The leakage port H9 is provided in this plug I I8.

Alongside of the chambers H2 and H3 there is formed the plunger space I20 connected to the space above the metering port H5 by means of the passage Hi. There is placed a sleeve I22 in the space I20, which sleeve corresponds to the ring 15 heretofore referred to, and said sleeve is capable of rotation through a limited are by means similar to that shown in Figures 16 and 17. The plunger element I23 works in said sleeve; and the sleeve and plunger element are locked together by suitable splines and spiral grooves, in manner similar to the arrangements already described. Thus, the plunger element ['23 may be provided with the splines I24 working in spiral 17 grooves extending along the inner surface of the sleeve I22, so that, after rotation of the sleeve has been stopped, further projection of the plnger element will cause rotation of said plunger element in manner similar to the arrangement of Figures 16 and 17.

A retraction spring I25 connects the plunger element to a plug I26 in the upper end of the unit, so that proper retraction of the plunger element is assured after reduction of pressure, and in manner similar to that already explained.

The cutter head and sampling chamber elements are shown at I21. They normally stand just within the confines of the body of the device, but are projected directly out therefrom during the working stroke. The detail of these parts need not be repeated at this point as they may be similar to the structures already described and illustrated, or may be of any suitable design. These parts are, however, accommodated Within the recess I28 of the body of the unit.

Suitable connection is established between the plunger element I23 and the cutter head and sampling chamber elements I21 so that these parts are compelled to move back and forth, and to rotate in harmony. It is noted that such connection must be such that proper provision is made for the change of direction due to the fact that the plunger element moves longitudinally of the body of the unit and the cutter head and sampling chamber move transversely thereof. In the form shown such connection is established by means of a flexible spring element I29 working in a passage of size to nicely accommodate it without excessive friction, and still with proper guidance. One end of this flexible spring element I29 is connected to the plunger element I23, and the other end thereof is connected to the cutter head and samplin chamber assembly I21. The passage through which this spring element works comprise the inside of the sleeve I22 together with the passage ISO in direct connection with said sleeve passage and extending through the body of the unit, and with an easy turn to the recess I28 already referred to.

It is noted that the spring element I29 is subjected to large forces of pressure as well as rotation during the working or projecting stroke. I prefer to make this spring element in the form of inner and outer closely wound springs I3! and I32, as shown in Figure 19, said springs fitting snugly together, and being spiralled in opposite directions; and furthermore, such spiralling is in such directions that under the turning force needed to rotate the cutter head during the working stroke the outer spring I32 tends to close down on to, and clamp against the inner spring I3I, and the inner spring, on the other hand tends to open up and spread out against the inside face of the outer spiral. The spring element shown in Figure 19 is intended to have the plunger element connected to its upper end, and the cutter head assembly connected to its lower end; and the ends of both the inner and outer spring I3I and I32 should be strongly connected to the respective elements so that proper transmittal of forces between the parts will be assured. The spring element shown in Figure 19 is substantially full size for one unit construction.

Now it will be seen that with the arrrangement of Figures 18 and. 19 a very large projection of the cutter head and sampling chamber assembly is possible. For example, with a sampling unit of, say, five inches diameter and length 18 of, say sixteen inches, it is readily possible to make provision for a projection of seven inches beyond the face of the unit, thus providing for penetration of probably four to six inches into the native rock, with consequent procurement of a large and typical sample thereof.

It is noted that .with each of the embodiments of my invention herein shown the motive power or energy i released in the first instance by a combustion or explosion action, but that this action is not delivered directly to the plunger element, but is delivered indirectly and under perfect control. The generation of pressure in the combustion chamber in the first instance will depend on many factors, including the density of loading, as well as the composition of the propellant. Sometimes it will be found desirable to use a relatively low density of loading so that the pressure originally generated will not be excessive, but still a very large amount of energy will be released in the form of gases under pressure in the combustion chamber and immediately connected parts. For example, this pressure might be of the order of thirty thousand pounds per square inch; and the energy released may be of the order of 1,200,000 ft. lbs. per pound of propellant. The temperature will be of the order of five to six thousand degrees F.

Now as soon as gas pressure builds up after commencement of combustion (initiated by the heating or fusing of the link 38), such gas pressure will tend to force the partition 42 to the right (see Figure 1), thereby displacing the liquid in the chamber 39 through the metering port 46 and passage 41, and forcing the plunger element to the left. The movements of liquid between the partition 42 and the plunger will be determined by the laws of flow of such liquids, including flow through the port or orifice 46. In case of rapid flow through said orifice there will be loss of potential or pressure at the position of said orifice, and during the interval of flow of liquid therethrough; but when flow of liquid ceases (as when the plunger ceases advancement or projection), or when such flow rate is reduced (as when the plunger movement is slowed down by cutting contact with the native rock), the loss of pressure at the port or orifice will fall, and the pressure against the plunger will rise (within the limit of pressure then existing in the device). In other words, at any given time the gas pressure existin within the combustion chamber and against the left hand face of the partition 42 is equal to the static pressure existing on the plunger element (due to resistance being met by the cutter head), plus the dynamic or velocity pressure loss occurring through the metering orifice. This latter must at every instant be of amount to take up the difference between gas pressure and static pressure head needed to penetrate the face of the wall (plus friction losses which will be negligible in comparison). In other words, the velocity of projection of the plunger element will at all times be determined by the differential between the gas pressure then existing and the pressure needed for cutting and penetration. As the latter rises the velocity of advance will fall, until at a slow rate the full available pressure of the gas will be used to force the cutter head forward with rotation and cutting penetration into the native material of the stratum.

The size of the orifice 46 will be determined by test in various cases; but will generally be of the order of one-eighth to one thirty-second 19 of an inch diameter. In Figure 1 I have shown by the dotted lines a small orifice 46 representing use of a metering plug having such smaller orifice in place of the plug with the orifice shown by means of full lines.

It is here noted that the velocity of projection of the plunger element will bear a ratio to the velocity of flow of the liquid through the metering orifice dependent on the relative sizes of the metering orifice and the efiective area of the plunger element. We have already mentioned that with the full size scheme shown in Figure 1 the effective area' of the plunger element is substantially 1.80'sq. inches. With a metering orifice of, say, one-sixteenth inch diameter (the openin 46 said orifice will have an area of substantially 0.003056 sq. in. and the ratio between the effective plunger area and this orifice area will be substantially 1 to 590. This means that under these assumptions the velocity of advance of the plunger will be substantially one five hundred and ninetieth the velocity of flow of the liquid through the orifice.

If the gas pressure be assumed as, for example, 30,000 lbs/sq. in., the theoretical velocity of the liquid flowing through an orifice cannot exceed substantially 2170 ft./sec. (for a liquid of specific gravity of 0.40 assumed for the oil). This means that under the condition of free exit of the liquid from the chamber 39 and without any retarding action due to presence of liquid in the passage 47, the velocity through the orifice or metering opening cannot exceed 2170 ft./sec. Consequently, with the assumed ratio of orifice area and plunger area, the maximum velocity of advance of the plunger cannot exceed substantially 2170 divided by 590 (ratio of areas), or approximately 3.67 aft/sec. In actual practice, for the assumed conditions of 30,000 lbs/sq. in., and metering orifice of diameter, and effective plunger area of 1.80 sq. in., the maximum velocity of advance of the plunger element, when encountering no resistance (as when projected in free air without being lowered into a bore hole) will probably be of the order of 3.00 or less ft. /sec.,

possibly as low as one foot per second. Of course as the cutter head encounters resistance due to contact with the native rock of the wall of the bore hole, this resistance will slow down the rate of advance, but the force which will be exerted by the plunger element will become equal to whatever amount is required to continue the penetration at the instant in question (up to the full available force created by the gas pressure then existing).

In other words, the device is automatic in the sense that rate of advance is limited in any case; and at any given instant the rate of advance will be reduced to an amount such that the force will build up to that amount needed to continue the advance (within the limits available).

A further result of this condition is that at all times the device is protected against damage due to possible excessive velocity of projection of the plunger element. Said plunger element is not a projectile, and it does not attain its result of penetration and sampling by reason of velocity; but it is truly a pressure device, and attains its function by static pressure exerted in great degree, and under full control at all times. Even if the propellant charge should be ignited under conditions such that no resistance would be encountered by the cutter head (as for example, in

case the cutter head should enter a pocket in the wall of the bore hole) no damage would result to the sampling device, since the rate of advance of the plunger element would be so slow that the impact at termination of travel would be small and inconsequential. In this connection it is noted that the projecting movement of the plunger element is limited, in the case of the device of Figures 1 to 15, inclusive, by engagement of the lugs 82 against the ring 15, and in the case of the device of Figures 16 and 17, by engagement of the flange 82 with the ring 80.

It is also noted that after reduction of gas pressure through the leakage port 56, to a point such that return movement of the plunger element may commence under the force of the retracting spring, the oil or other liquid must again return to the chamber through the metering orifice 46; and such returning movement of said oil will also be subject to the laws of flow of liquids through orifices.

Insofar as concerns the ignition of the propellant charge any suitable scheme of electrical connections may be used to deliver the impulse of current to the circuit including the fusible element 38. I shall, however, now describe the arrangements herein disclosed for accomplishing the foregoing result, and for securing certain other and desirable functions.

Preferably one of the spring contacts engaging the propellant charge fuse, is grounded, being the contact 33 which is connected to the bod of the device. On the male connector element 27 I mount an insulating plate I33, having therein several circular contact rings I34, I35, I36, I31 and I38 (or as many as desired) and these contact rings are connected to the wires of a plural conductor I39 extending down through suitable passages in the body of the sampling unit. The wire from the central contact I38 is carried directly to the spring contact 34 for the propellant charge of the sampling unit in question, by a conductor extending through the passage I40. Thus, whenever the central conductor or ring of the insulating plate I33 is properly electrified the propellant charge of this particular sampling unit will be fired.

Within the female connector element 28 I mount an insulating cup member I4I, having therein the several circular or ring contacts I42, I43, I44, I45 and I46, to which are connected the spring contacts 200 as shown in Figure 1, said spring contacts extending down in position to engage with the circular contacts of the plate I33 of the sampling unit next below the one now being described. Now, within the sampling unit being described, the outermost ring contact I34 is connected to the next to the outermost ring or contact I43 at the bottom end; the next ring contact I35 is connected to the ring contact I44 at the bottom end; the next ring contact I36 is connected to the ring contact I45 at the bottom end; and finally the next ring contact I3! is connected to the central contact I46 at the bottom end. In other words, the central contact at the top end connects to the firing fuse of the propellant charge of the sampling unit in question; and each of the other upper contacts connects to a lower end contact progressively further in towards the center of the device. As a consequence, when several such units are connected together by threading their male top connectors into the female bottom connectors of the successive units, there is established a continuous series of connections through the entire group of units, and

with each unit separately controlled from above, and therefore under perfect independent control.

At this point I mention that I have also provided each of these samplin units with a band or electrode I41, carried in a band of insulating material, and preferably located near the bottom end of such sampling. unit, as shown in Figure 1. Also, in each case such electrode is electrically connected to the same. wire which is connected to the contact 34, and therefore to the central top contact I38, so that said top contact (central) I38 may be used either for delivery of current for firing the propellant charge or for electro-logging operations, as will presently appear.

It is also here'noted thatwith the arrangements so far explained the several sampling units may be connected together in any selected order, and in all such cases proper connections will be necessarily established to the firing fuses and to the: electrodes for the electro-logging operations.

If desired the surfaces of the sampling unit may be coated with suitable insulating material so that during various operations improper rounding will not occur, as for example when conducting electro-loggin operations. It will sometimes be found unnecessary to provide such insulation, but I contemplate the same whenever needed. I

It is, also here noted that when the male connector 21 of one sampling unit is connected tightly into the female connector of the next higher unit, th insulating plates I33 and MI are brought very firmly together with a sealing action, so that a tight chamber I48 is established in the body of the joint, and so that water and mud or other conducting liquids are excluded from the contacts at the points of junction from unit to unit.

Now referring to Figure 20 I have therein shown more or less diagrammatically one set of connections for use of a group of these units during a sampling and also during an e1ectro-log ging operation. In this case I have assumed that five of the sampling units are to be used (it being noted that in theforms of connectors shown in Figure 1 there are five contact rings), These are the unitsv I49, I58, I5I, I52 and I53, respectively. (It is noted that a special unit IE4 is also shown in Figure 20, but same is not a sampling unit, and is not used for sampling purposes, and constitutes merely a "spacer unit under some condi tions, as will presently appear.) These several units are all connected together, the lines I55, I56, I51, I58 and I59 extending from the cable I60 to and through the several units and being therefore connected to said units as shown, it being noted that the spacer unit has connections which extend directly through it. It is also noted that the cable is readily connected to the male connector of the top unit of th group by means of the head element I6I. Preferably, also, th female connector of the bottom unit of the group is closed by a plug I62 (shown in Figure 20) which plug is conveniently made of tapered section so that during the lowering operation into the bore hole the entire assembly will readily find its Way past irregularities in the hole.

The mechanical connection between th lower end of tht cable and the head element is not shown as manifestly same constitutes no portion of the present invention, but it will be understood that said cable constitutes the means whereby the entire assembly is lowered and raised in the borehole,

Said cable I passes over suitable pulleys or the like I63 at th ground level, and on to a winding drum I64 whereby the raising and lowering operations are taken care of. Such arrangements are well known and understood in the art of electro-logging.

The conductors I55, I56, I51, I58 and I59 of the cable are brought out from the drum I64 and through a cable I65 to the like lines as shown in Figure 20. A suitable source of current, such as a battery I66 is provided at the ground level. The head member I6I of the group of sampling units is effectively connected to the tension strands of the cable I60 by the ground line I61; and at the control stand on the ground level there is a switch I68 by means of which said tension strand or strands of the cable may be connected to one side of the battery, preferably the negative side thereof, .by suitable protection of the fuse I69, and lines I10 and HI. When the switch I68 is opened the good ground connection is broken.

The other side of the battery connects by a line I12 to a bus bar I13; and there are provided control firing switches I14, I15, I16, I11 and I18 corresponding to the several sampling units of the group. These switches connect the bus bar I13 to the respective lines coming from the sev eral sampling units as will be readily evident,

It is now seen that upon closing the grounding switch I68, any selected sampling unit may be fired by merely closing the corresponding firing switch I14, I15, I16, I11 or I18 as the case may be; or that two or more of the sampling units may be fired simultaneously if desired for any reason.

I have in Figure 20 shown more or less diagrammatically the two galvanometers I19 and I88, respectively, same being of suitable form, but preferably of the reflecting type. The galvanometer I19 is connected by the leads I8I and I82 to the lines I56 and I12; and the galvanometer I89 is connected by the lines I83 and I84 to the lines I55 and I 59, respectively.

It is now noted that when a group of the units is let down into the bore h'ole I85 the electrodes of the several units will occupy relative positions in the bore hole such that electro-logging operations maybe performed upon connecting said electrodes properly to the galvanometers I19 and I86 and it is possible to perform electro-logging tests by use of these electrodes. For simplicity I have herein designated the five units to which the lines I55, I56, I51, I58 and I59 are connected by the letters A, B, C, D and E, respectively, and I have also designated the unit between the units A and B, and to which no line is connected, by the letter S (for spacer). This unit is also designated as 25 Now it is further noted that the electrodes of the units B and C are relatively close together; and that the unit E is separated from the unit C by the interposition of the unit D and that the unit A is separated from the unit B by the interposition of the unit S.

According to certain well known and widely practised systems of electro-logging the following procedure is used: current is passed between the electrodes B and C, being indicated or recorded by a suitable galvanometer (and usually a permanent trace of the value of said current is created by use of a beam of light directed onto a recording photographic strip); and at the same time that this current passes between the electrodes of units B and 0 there will be caused to flow a current between the electrodes A and E,

due to side leakage of current through the strata of the native rock beyond the bore hole; and the value of such leakage current between said electrodes A and E may be used to determine the resistance of the strata, which resistance is, in turn an indication of the presence of such materials as oil and the like in said strata. The rise of such resistance'will usually be great in the presence of oil bearing strata. According to this scheme it is usual to make use of the deflection of the galvanometer I88 to indicate such resistance so that by making a photographic record of the deflection of said galvanometer we are able to permanently record the nature of the strata at different elevations of the bore hole.

It will thus be noted that a group of my sampling units may be readily used in connection with electro-logging operations, by merely providing suitable means for using the proper electrodes during such electro-logging operations. For this purpose I provide the test switch I86 which may establish connection between the line I51 (from the unit C electrode) to the line III which leads to the negative side of the battery, by means of the lines I81 and I88, respectively. Upon closing this test switch we have the following operations: A circuit is established from the positive side of the battery through the galvanometer I19, through the line I56 to the electrode of the unit B,

through the material around the units in the bore hole to the electrode of the unit C, through the line I51 and test switch back to the negative side of the battery. This will produce a local current through the strata or material close to the units B and C in the bore hole, and the value of this current will be shown by the deflection of the galvanometer I79, and may be recorded as a curve on a suitable photographic strip during the vertical movements of the test units through the bore hole. Such a curve is shown at I89 on the strip I99 (elevations in the bore hole being shown along the length of said strip).

At the same time, the presence of the local current between the electrodes of the units B and C will cause flow of the secondary current between the electrodes of the units A and E, which, in turn will be the measure of the resistance of the more distant strata, and by suitable means the inverse of this current may be plotted or shown on the strip I 90 as a curve I9I. The values of this curve I9I will therefore be a measure of the resistance of the strata, and therefore an indication of the presence of such materials as oils and the like therein.

In connection with the foregoing it may be noted that the terminals of this galvanometer I89 are permanently connected (if desired) to the lines I55 and I59 which connect to the electrodes of said units A and E, so that indications of this galvanometer will be given also by merely closing the test switch I86.

Now it is usual to use the electrodes of said units A, B, C and E to trace the curves I89 and I9I during a rising or withdrawing of the units from the bore hole, having previously, by suitable means, caused the tracing of a curve I92 on the photographic sheet or strip I98 to indicate the natural potential of the various strata. It will be noted that in a typical set of curves so traced or produced there will occur severe deflections such as at I93 and I94'in the curve I9I, the same indicating great and sudden variations of strata resistance, and being indicative of the presence of such desirable materials as oil in said strata. It is also noted that during the operations of producing these curves it is necessary to resort to special means, such as calibrations of cable stretch and the like under difierent loading onditions, to know exactly how low the test electrodes stand in the bore hole at the positions of such severe deflections, or other locations. Still, when once the curve I9I has been traced the locations of the severe deflections, such as I93 and I94 will indicate locations at which it may be desired to take side-wall samples in order to further test or check the accuracy of the indications of such curve, and the meanings of the deflections thereon shown. Said curve I9I may be traced in the first instance by use of the electrodes carried by my sampling units or by other means let down into the bore hole, as desired.

Now, having in hand a curve such as that shown at I9 I, procured either by means of my sampling units or by other separate test equipment, it will be seen that as a group of my sampling units is let down into the bore hole, the test switch I86 may be kept closed, so that during such lowering operation the galvanometers I19 and I89 may be caused to trace curves I95 and I96, respectively, on a strip I91 of sensitized material; and during such lowering said curves will closely follow the forms of the curves I89 and I9I of the electro-logging strip I90, which curve I9I contains the severe deflections I93 and I94 whose significance it is desired to check and further analyze by procurement of samples from the side walls of the bore hole. When, therefore, during such lowering of the group of my units, with the test switch closed during such lowering, the curve I96 reaches the location of the severe deflection (for example, I98, corresponding to the deflection I93 of the curve sh'eet I), there will be immediate indication that the sampling units have now reached the location of the exact stratum which it is desired to side-wall sample, and further lowering may now be arrested. Such indication of correct elevation and position of the sampling untis will be made with great exactness, and irrespective of exact elevation of the stratum measured in feet below the surface, and will be an indication of the position of the sampling units with respect to the stratum itself. Furthermore, this means of locating the sampling units in the bore hole completely eliminates uncertainties of cable stretch, and the necessity of cable calibration for such stretch, and ensures a reference of the location of the sampling units directly to the electro-logged position of the stratum which it is desired to analyze, without need of other comparisons or calculations.

Having so located the sampling units at the exact position desired in the bore hole it is then possible to fire any one or more of the sampling units by merely closing the switches I14, I15, I 16, I I1 and I18 to thereby selectively or simultaneously fire said sampling units at such location. In this connection, as a further refinement, and knowing the exact vertical dimensions of the sampling units, it would be possible to slightly adjust the elevation of the group of sampling units between firing of successive units, so that all the samples would be taken at exactly the same elevation, even to the fraction of a foot.

Now in connection with the foregoing operations it is noted that inadvertent closing of the test switch I86 and the firing switch I'I6 for the unit C simultaneously, the ground switch I68 being also closed, would result in short circuiting of the battery with consequent blowing of the protective fuse I69. In order to provide a protection against such inadvertent simultaneously closing of the switches I 86 and I16, I prefer to provide a suitable interlock I 99 whereby said two switches cannot be closed at the same time.

It is further noted that by provision of suitable insulating material on the outer surfaces of the various sampling units, the conducting of the electro-logging tests hereinbefore described will not be interfered with by improper flow of nondesired local currents at the location of the sampling units. Thus, for example, such insulation Will prevent the short-circuiting of local stratum currents by the considerable vertical dimension of the group of sampling units themselves.

It is further noted that generally it is desired to have the electrodes B and C close together, and with the electrodes A and E quite removed from each other vertically, so s to ensure measurement of local stratum currents through a corresponding and known range of native rock deposits. When using five sampling units, as shown, it is therefore desirable to place a dead or spacing unit 25 between the units A and B so that the distance between the units A and B will be equal to that between the units C and E, the unit D being a live or sampling unit. By this means proper complete spacing of the used electrodes willbe ensured.

Now it is also to be noted that upon closing of the test switch I86 the line I51 for the sampling unit C is connected to the battery. However, the fact that the ground switch I68 is still open will prevent premature firing of the propellant charge of said unit 0. It is further noted that the line I56 for the unit B is at all times connected to the positive side of the battery, but such connection is made through the galvanometer I19 which is high resistance, and therefore does not of itself permit flow of suflicient current to fire the propellant charge of said unit B. Such charge will only be fired upon closing of the switch I15, the ground switch I 68 also being closed. It is likewise noted that both of the lines I55 and I50 for the two units A and E are permanently connected together, but through the high resistance of the galvanometer I80; and hence the closing of either the firing switch I14 or the firing switch I18 will result in firing only the intended unit, since sufiicient current cannot reach the other unit through said galvanometer to fire such other unit.

It is also noted that the firing of any unit will cause a momentary disturbance in the indication being given by the galvanometer I80, and therefore in the form of the curve I96 at the position of the severe deflection I98 noted thereon. This is true because of the disturbance to the currents flowing through the several circuits caused at the instant of firing any sampling unit of the group. Consequently I have provided a means for making a permanent record of the exact locations at which side-wall samples have been taken, said record being a portion of the record of the electrologging operations themselves.

It may be noted that whereas the mechanical connection between the successive units as shown in Figure 1 is more or less rigid, it would be possible to make use of flexible connections between the units, as for example, the hook and eye arrangements shown in Figure 18. By this means a group of such units would be enabled to more readily follow sudden variations in form or direction of the bore hole.

said lines extending down from the ground level to the stratum being analyzed or tested. These lines generally are contained Within or carried by the cable which serves to carry its own Weight as well as the weight of the devices secured to its lower end; and it has been found that the large tensions to which such cable is subjected, as well as the severe pressures exerted on the lays of said cable where it passes over pulleys or onto the winding drum present conditions resulting frequently in short circuiting or other damage to the electrical lines carried by the cable. Such tendency is aggravated by increase of the number of the electrical lines which must be carried by the cable; and by my scheme of using the same lines for both the electro-logging and testing functions, as well as the firing of the propellant charges I reduce the total number of lines necessary accordingly with consequent great benefits.

It is noted that there is practically no tendency for leakage of either gas or liquid past the partition or plunger 42, since the pressures on both faces thereof are equal (disregarding very slight friction); and said partition serves primarily to keep the gases and the liquid isolated from each other.

It is noted that in the schemes herein illustrated the travels of the partitions 42 (see Fig. 1) or H4 (see Fig. 18) bear a relationship to the travels of the plungers 60 (see Fig. 1) I23 (see Fig. 18), respectively, dependent on the relative areas (efiective) of said parts. Hence it is possible to so design the device that the partition I I4, for example, may have a smaller travel than that of the working plunger.

The combustible charge or explosive used in the chamber 29, or IIZ, as the case may be will be selected according to the wishes of the user; but generally it should be a slow-burning propellant, and may be a nitro-cellulose. For example, deca-nitro-cellulose may be used, having substantially 6% moisture, and .4% stabilizer, said propellant having substantially 1,266,000 ft. lbs. energy released in the form of heat. per pound burned, at release to sea-level pressure and normal temperature. This propellant occupies substantially 27.66 cu. in. per pound.

If We assume an eifective pressure of substan tially ten thousand pounds on the cutter-head during a stroke of, say three inches, there will be consumed 2,500 ft. lbs. of energy. If therefore we make provision for release of 25,000 ft. lbs. of energy in the combustion chamber We shall have a factor of safety of ten to one. Such amount of energy may be readily released in thecombustion chambe when using the deca by use of a capsule or charge of, say, .019'74# weight] This will occupy a space of approximately .5449 cu. inches; so it is possible to readily accommodate such charge in the combustion chamber of, say 3 inches long by 1 inch diameter, as illustrated in Figure 1 of this case, and with a low density of loading. In fact, a considerably smaller chamber may be used, depending on the desired density of loading.

It is also noted that after complete combustion, and prior to completion of travel of the part tles 4 the expansion of the gases will be adiabatic, and will conform to the laws of adiabatic expansions, subject to heat losses to the walls. In this connection it is to be noted that event with a release of, say, 25,000 ft. lbs. in the form of beat this will be equivalent to 32.13 B. t. u., so that excessive heating of the metal of the chamber and other parts will not occur. Still, it may be found desirable in some cases to line the walls of the chamber 29 and passage 4| with hard heat-insulating material, such as compressed asbestos, or other material.

I claim:

1. Means to take and recover a sample of material from the side wall of a well bore, or the like, comprising a body of size to be lowered into said bore and provided with a radially extending cylindrical opening in communication with the exterior of said body, a plunger and cutter head assembly reciprocably and rotatably mounted in said cylindrical opening and including a circular cutter head of annular form surrounding a pocket o chamber in said assembly, said body also being provided with a chamber for accommodation of a charge of explosive combustible, and with another chamber for accommodation of a free piston movably mounted therein, and said body also having a gas passage connecting said explosive combustible chamber with one end of said free piston chamber and having a liquid passage connecting the other end of said free piston chamber with the radially extending cylindrical opening at a position behind the plunger assembly, there being a free piston working in the free piston chamber between the connections of said passages with said chamber ends, and serving to segregate 9 liquid in one portion of said free piston chamber from gas in the other portion of said free piston chamber, a ported partition extending across the liquid passage aforesaid, the port whereof is of small cross-section to thereby check flow of liquid therethrough and thus to check the rate of delivery oi said liquid to the cylindrical opening behind the plunger assembly, co-operative rotative means in connection with said body and said plunger assembly constituted to cause rotation of said plunger assembly during at least a portion of the reciprocation thereof in said body, and a spring connected to the plunger assembly and to the body and tending to draw said plunger assembly inwardly in the radially extending cylindrical opening of the body and within the confines of said body, together with electrical connections carried by said body for engagement by an explosive cartridge placed within the explosive combustible chamber for ignition of said cartridge when said electrical connections are electrically energized, substantially as desired.

2. Means to take and recover a sample of material from the side wall of a well bore, or the like, comprising a body of size to be lowered into said bore and provided with a radially extending cylindrical opening in communication with the exterior of said body, a plunger and cutter head assembly reciprocably and rotatably mounted in said cylindrical opening and including a circular cutter head of annular form surrounding a pocket or chamber of said assembly, said body also being provided with a chamber for accommodation of a charge of explosive combustible, and with another chamber intermediate between said cylindrical opening and said explosive combustible chamber, and said body also having a gas passage connecting said explosive combustible chamber with one portion of said intermediate chamber, and having a liquid passage connecting another portion of said intermediate chamber with the radially extending cylindrical opening at a position behind the plunger assembly, said gas passage connecting into said intermediate chamber at a position higher than the connection of said liquid passage into said chamber, whereby said passages establish gas and liquid connections to said chamber, respectively, a ported partition extending across the liquid passage aforesaid, the port whereof is of small cross-section to thereby check the flow of liquid therethrough and thus to check the rate of delivery of said liquid to the cylindrical opening behind the plunger assembly, said intermediate chamber, liquid passage and port of said ported partition, and said cylindrical opening behind the plunger assembly being adapted to receive and retain a body of liquid filling said liquid passage and port, and filling said space behind the plunger assembly, and filling said intermediate chamber to a pressure surface of said body of liquid which pressure surface contacts the walls of said intermediate chamber on a continuous line of contact which line passes between the connection of the gas passage into said intermediate chamber and the connection of the liquid passage into said chamber, whereby pressure exerted through the gas passage from the explosive combustible chamber into said intermediate chamber acts through the intermediary of said pressure surface of said body of liquid to place said body of liquid under pressure dependant on said gas pressure, and said body of liquid acts through said port of said ported partition to exert pressure against said plunger assembly, co-operative rotative means in connection with said body and said plunger assembly constituted to cause rotation of said plunger assembly during at least a portion of the reciprocation thereof, in said body, and a spring connected to the plunger assembly and to the body and tending to draw said plunger assembly inwardly in the radially extending cylindrical opening of the body and within the confines of said body, together with electrical connection carried by said body for engagement with an explosive cartridge placed within the combustible chamber for ignition of said cartridge when said electrical connections are electrically energized, substantially as described.

3. Means as defined in claim 1, wherein said ported partition includes a ported plug removably mounted in said partition and said plug having a ported opening of calibrated size, substantially as described.

4. Means as defined in claim 1, wherein said body is provided with a leakage port extending from the explosive combustible chamber to the outside of the body, substantially as described.

5. Means as defined in claim 1, wherein said body is provided with a leakage port extending from the explosive combustible chamber to the outside of the body, and a fusible plug closing said leakage port and fusible under temperatures generated by the combustion of the explosive cartridge, substantially as described.

6. Means as defined in claim 1, wherein said body is provided with a port extending from the explosive combustible chamber to the outside of the body, together with a removable ported plug inserted in said body port and having a leakage port of calibrated size, substantially as described.

'7. Means as defined in claim 1, wherein said ported partition includes a ported plug removably mounted in said partition and said plug having a ported opening of calibrated size, and wherein said body is provided with a port extending from the explosive combustible chamber to the outside of the body, together with a removable ported plug inserted in said body port and having a leakage port of calibrated size, substantially as described.

8. Means as defined in claim 1 wherein said means to rotate said plunger assembly acts to rotate said plunger assembly in one direction during outward projection of said assembly against spring tendency, substantially as described.

9. Means as defined in claim 1, wherein said means to rotate said plunger assembly acts to rotate said plunger assembly in one direction during outward projection of said assembly against spring tendency and acts to permit retraction of said plunger assembly by spring tendency without rotation of said assembly during such retraction, substantially as described.

10. Means as defined in claim 1, wherein said means to rotate said plunger assembly acts to permit initial projection of the plunger assembly outwardly against spring tendency and without rotation of said assembly, followed by rotation of said assembly during further outward projection of said assembly, substantially as described.

11. Means as defined in claim 1, wherein said means to rotate said plunger assembly acts to permit initial projection of the plunger assembly outwardly against spring tendency and without rotation of said assembly, followed by rotation of said assembly in one direction during further outward projection of said assembly, and wherein said means to rotate said plunge rassembly acts to permit initial retraction of said assembly under spring tendency with an initial retraction without rotation, followed by rotation of said assembly in the direction contrary to said rotation during outward projection aforesaid, substantially as described.

12. Means as defined in claim 1, wherein said plunger assembly includes a plunger element reciprocably and rotatably mounted in said cylindrical opening of the body and an annular cutter element removably connected to said plunger element removably connected to said plunger element, substantially as described.

13. Means as defined in claim 1, wherein said plunger assembly includes a plunger element reciprocably and rotatably mounted in said cylindrical opening of the body, and having a material receiving chamber, together with an annular cutting element removable connected to said plunger element, substantially as described.

THOMAS A. BANNING, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,303,727 Douglas L Dec. 1, 1943 2,131,980 Seale Dec. 5, 1939 1,560,492 Powell Nov. 3, 1925 2,344,598 Church Mar. 21, 1944 Re. 20,120 Schlumberger Sept. 29, 1936 2,055,506 Schlumberger Sept. 29, 1936 1,338,676 Constantinesco May 4, 1920 2,067,693 Carey Jan. 12, 1937 2,173,532 De Long Sept. 19, 1939 2,005,913 Coffman June 25, 1935 1,935,123 Lansing Nov. 14, 1933 FOREIGN PATENTS Number Country Date 548,727 Great Britain Oct. 22, 1942 OTHER REFERENCES SchlumbergerSide Wall Sampling-A bulletin recd. Feb. 10, 1939; pgs. 1-4 inc,

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