US2381844A - Core taking apparatus - Google Patents

Description

.1. c. s'roKEs CORE TAKING APPARATUS Aug. 7, 1945.

f Filed May 11, 2 L94Z M Y "lillllllw Afro/P Patented Aug. 7, 1945 Y l-rcom; TAKING APPARATUS John Stokes, Houston, Tex., assignor to Reed Roller Bit Company, Houston, Tex., a corpora-Iv tion` of Texas Application May 11, 1942, Serial s claims. '(ol This invention relates in general to core take ing apparatus and has for itsgeneral object the provisionA of a novel and advantageous means for suspending for free rotation during the taking of a core the core barrel which is adapted to receive the core.

It is customary in connection with core taking apparatusnof the type' in which the'core receiving vbarrel is carried within an outer barrel and inserted into the well when the drill stem is runvin,

to provide somev` means whereby the'inner core barrel assembly may be suspended so that it may rotate freely during the taking oi a core.- However, such means in the past have consisted of some sort of mechanical latching means where-y by the core barrel assembly is latched within the outer barrel so that it will be suspended within the outer barrel from its upper end. Such a relatively small diameter,

form of suspension makes-it necessary that before thevinner barrel 'can be removed for the purpose ofremoving and examining the core,A some mechanical latching means must be ilrst releasedl The presence of vs uch latching means kkalso introduces the ever present hazard that the latching means may accidentally become released l during the use of the device and thus render useless the intended means for suspending the inner core barrel.

It is therefore an vobject of the present invention to provide-a means for suspending an inner core barrel which means will not involve the use of any mechanical latching device. y y,

Another object of this invention is to provide a suspending means for an inner core barrel assemblyywhich suspending means will automatically be released upon withdrawal'of the device to the surface of the ground after the taking of a core, so that the inner core barrel assembly may be withdrawn from the outer barrel without necessity for releasing any'latching device whatever. v

Other objects and advantages of this invention l will become apparent from the following descrip7 tionY taken in connection with the accompanying drawing wherein is set forth by way of illustration one embodiment of this invention. In the drawing: Fig. 1 is a longitudinal cross section through theupper portion .of the device constructed in accordance with this invention.` y

Fig. 2 is a similar view through'the lower portion of the same device. Fig. 3 is a view similar to Fig. 1 the position occupied bythe various parts when the d'wice is vat the surface of the ground and not Vturn carried by the lower end of r No. '442,401

. ass-12) l A under y the iluidv lpressure -which exists at the bottom of. a well. e

, Fig. 4 shows across section taken along the yline f4 of Fig. 3.

Referring now more articularlysto the drawing, theouter core barrel is illustrated at l and has threadedly secured toits upper end a collar 2, the same being welded to the outer corebarrel 'at 3 to provide a more secure Joint, The upper end of the collar 2 is internally threaded for the purpose of receiving the special sub 4 that is in the drill stem; This special sub 4 has a bore therethrough with zones of various -dierent diameters. An upper portion of this bore is provided with a zone b of this zone having a recess 6 interrriediate its ends adapted to receive a U,shap`ed packing member l sri-disposed as to prevent the passage of fluid downwardly about a cylindrical 4member located in this portion of the bore as will be presently described. low the zone 5 isa zone 8 of relatively much larger diameter-and below this zone @is a third zone @i which is again of a smaller diameter but not oi as small diameter as the zone 5. Just below the zone is still a fourth zone I0 of slightly larger diameter than the zone 9 so as tovprovide a shoulder it therebetween. l y

' The lower end oi the outer barrel i is threaded to receive the upper end ofia sub i2 which is additionally secured to the outer: barret by means o'f welding i3. This sub l2 is threaded at its lower kend to receivethe core drill @d which may be of any usual or desired vconstruction andL in the present instance isshown as provided with roller cutters I5 and i6 such as are ordinarily. used for the purpose of drilling through'hard of the-'inner barrel, and a suitable core catcher,

but showing element i9 is carried within the drill bit lli inst belowI the lower end of the iitting i8. A suitabie protector sleeve 20 is`initially suspended upon the core catcher i 3 and prevented from upward movement into the core barrel by means of the projections 2| adjacent its lower end. The'se projectionsy 2| are mounted on exible parts of the sleeve 20 so that when a substantial amount .of force is exerted on thelower end of the'sleeve 20 it may be forced upwardly into `the core barrel. Suspension ofvthis sleeve 20 by means of the core catchers I9 is made possible by virtue of the tact that the outer surface of the sleeve 2B adjacent nection being locked by means of a lock nut 3l.

Ithat shown lin Fig.

its upper end is notched as shown receive the core catcher lingers.

At its upper end the inner core.barrel I1 is provided with the usual core barrel head 2l which may be of any desired i'or'm. In this instance it is provided with an enlarged valve chamber 24 adapted to receive a ball valve 28 which is in turn held in `placeand prevented from upward movement out oi' the valve chamber 24 by means o! a tubular member 28. This valve 25 is adapted to seat against a valve seat 21 which is in turn held in place by means of a nut 2l. -:It will readily be seen that this valve will permit ilow upwardly from the inner core barrel during the taking o! a core but will not permit ilow downwardly into the inner core barrel. However, with this type of device it is intended that after the core barrel has been withdrawn from the well and it is desired to vremove the core, the core barrel may be laid on its side so that the valve 25 will move into a lateral portion lof the chamber 24, whereupon pressure fluid may be forced in through the tubularY` member 26 vto force the core of the core barrel.

Threadedly secured to the `upper end of the core barrel head 23 is acage 2 9 having lateral openings 30 therefrom. 'I'his cage 20 is suspended by means Iof *a suspension head Il threadedat 32 to the cage 29, this threaded conout oi' the lower end This suspension headis rotatably mounted be- .tween two suitable bearing rings 34 and II which may be of rubber or some similar materialr'the suspension head 3| having a flange 2l that fits' between these bearing rings.

.'I'he bearing yrings themselves are carried within a cup-shaped retainer 31 which has van inturned flange ll at its ls at its upper end lower end and is threaded at on to the plunger 40. g

The plunger'40 has a bore 4I therethrough oorresponding in` diametery to the diameter of the bore 42 through the suspension head II, and this plunger is also provided with lateral outlets 4I from this bore.

The plunger is provided with an upper cylin-` drical Part 44 adapted to be withinthe zone 5 oi' the special ntting 4, and with a lower part 45o! relatively larger diameterfadapted to -ilt within the zone I0 of the tting 4 but ofa suiliciently large diameter so that it will not pass Aupwardly past the shoulder II. This portion 4I is provided with a circumferential groove adapted' v to receive a sealing ring 48 which may be of U- as to prevent the shaped form and soudisposed ilow of any iiuid between the lunger 4l and the' inner surface o! the fitting 4 in an upward direc'- tion. 'I'he ring 1 previously mentioned also forms a seal about the portion 44 of the plunger and prevents the downward now Vof any iluid about the outside of this plunger and within the tting 4. There is thus provided what may be termed a diilerential piston, or one having a greater effective area at one end than at. the ult/her, so that when both ends are subjected to t e same pressure, the net result will be a force tending to move whichinthiscaseisinanupwarddirection.

Irr operation the device is placed within the well with the parts in the positions shown in the drawing with the exception that the plungerwill occupy the position shown in Fig.A 3 instead o! 1. `It will be seen that when the piston in one direction ing tending to raise the inner core barrel assembly to l 2,361,844 at 22 tol 4I. As the device is lowered into the well however, the pressure due to the drilling-huid in the well increases.l Due to the difiference in area between the portion 45 of the plunger 40 and the portion 44 thereof, this increase in pressure oi drilling iluid surrounding the device will have a diilerentialeilect tending to raise the inner core barrel assembly. When the pressure of the iluid surrounding the device becomes great enough this inner core barrel assembly will rise until the upper' end of the portion 45 of, the plunger 4G comes in contact with the'shoulder. II. This disposition of the various'parts is illustrated'in Fig. 1 of the drawing and it will be seen that in this figure the inner kcore barrel assembly will be suspended fromthe plunger 40.

With the parts in the position indicated the Vcore is taken, the core barrel assembly'within' the means of the differential ilad' essure.

After the core has been'taken the entire device is removed td the ysurface of the well. As it is withdrawn and the hydraulic pressure surroundthe device decreases,y the differential pressure its uppermost position as shown in Figs. 1 and 2 will decrease until the point is reached where this core barrel assemblywill drop down and the lower end of the inner core barrel will rest upon the interior ofthe drill bit I4.

When the device has been completely withdrawn from the well, the drill blt I4 may be taken oil' andv the entire inner core barrel assembly removed without the necessity for disconnecting any mechanical latch or other device of any kind.

It will thus be seen tha vided whereby the inner core barrel assembly of a coring apparatus may be suspended' during the taking of a core so that it may rotate freely, but this has been accomplished without th use of any mechanical latching mechanism which would require release before the inner core barrel assembly could be withdrawn, or which might become accidentally released so that it would be of no eil'ect. On the other hand, with the device provided bythe present invention a sure suspension is provided during the taking of a core.' and this the inner core barrel assembly of the l inner barrel the parts 2l, 2l, 3| and v4l car-y provided with radially suspending means is released automatically as the device is withdrawnfrom the well.

Means has thus been provided i'or carrying out all of the objects and advantages' sought by this invention. i

, While it forms fno part of the present invention, it will be understood that the tube 28 .may be left out when the device is run into the well and that the ball valve 2l may then be droppedinto place after the device is in place in the well. In order that the upper end of this tubular member 2| may be properly centered within the. bere through the plunger 40, the tubular member is extending ilngers or vanes which serve to center it within the plunger.

.f Having described my invention, I claim:

1. I n e, coring apparatus, an outer core barrel, an inner core barrel, and a dierential piston on the inner core barrel and iltting within the outer tra means has been proonthe surfaces when e under pressure.

- piston. having a passageway core barrel, said piston between 'said an inner core barrel. and a rangement comprising s. gas nlled spaced core barrel, said`pistcnhaving opposed suriaces of diiierent areas and arranged to be subjected to the action oi a fluid exerting the same pressure the device is immersed in said outer core barrel having a cylinshaped to receive'the piston and provide a space intermediate the diiierential surfaces of the piston containing a. compressible nuid, and sewing for suspending the inner core barrel' when the device is immersed in a fluid said iluid. der correspondingly 2. In a vcorina apparatus. an outer core barrel, Il inner core barrel, and piston on the inner core barrel and fitting within the cuter core barrel, said piston having opposed surfaces ci different areas and arranged to subjected to the same pressure on is immersed in saidfiluid, said outer core barrel having a cylinder correspondingly shaped to receive the piston and provide a space intermediate the diiierential surfaces of the piston containing a compressible iiuid, and `serving for suspending the inner core barrelwhen the deviceis immersed ina nuid under pressure, said.hollow therethrough ylongitudinally for the purpose of conveyingdrilling tluid therethrough.l I

3. In a coring apparatus, an outer core barrel,

action of a; uid exerting the. the surfaces when the devicev v arrangement comprising a relatively larger lower a hollow differential an inner core barrel, and a differential piston on the inner core barrel and tting within the outer having opposed surfaces oi diner-ent areas and arranged to be subjected to the action of a fluid exertin'g the same pressure on the surfaces when the device is immersed in said iluid, said outer core barrel having a cylinder correspondingly shaped. to receive the y piston and provide a space intermediate the difierential'surfaces of core barrel when Vthe device is immersed in a fluid 'under pressure,

piston and said inner core barrel whereby when said inner core barrel is suspended by .said lpiston the inner c'ore barrel may rotate .freelyduringithe taking oi a core. y

4. In 'a coring apparatus; an outer core barrel. diierential piston-ar?- a relatively larger lower and a relatively' smaller upper piston partk having therebetween at a pressure relatively lower than the pressure of the iluid in which said device is adapted to operate, said dinerential piston arrangement ntting within parteci the outer correspondingly dimensioned core barrel for suspending the inner core barrel when thedevice 'is immersed in a fiuid under pressure. In a caring apparatus, an outer core-barrel,

A an inner core barrel, and

and a swivel connection a diierentiai piston the-piston containing a compresi sible duid. and serving for suspending the im 4c.

' to both sides 0f the pistoxn Vunder pressure.

and a relatively smaller upper piston part and si.'- space therebetween lled with air at atmospheric differential piston arrangement the inner core barrel and fitting pressure, said being carried on within correspondingly dimensioned parts of the outer core barrel for suspending the inner core barrel whenthe device is immersed in a iluid 6. .In a coring apparatus, an

barrel', and means closing the upper end of said cylinder and providing a chamber above the piston containing a compressibleuid ycapable of compression when the apparatus isimmersed -in a fluid under pressure for suspension of the core barrel. v '1. In a coring apparatus, an outer core barrel, an inner core barrel, a cylinder `carried by the outer core barrel, a piston reciprocably mounted der; the lower end of .the cylinder being open to 'expose the under surface of the piston, and

uid under pressure to .I

means for supplying a v both the upper and lower surfacesl of the piston f to effect an upward movement of the piston and the inner core barrel due to the differential erfectof the pressure applied to both sides o! the y piston and suspend the inner core barrel.

`8. In a coring apparatus, an outer core barrel, an inner core barrel, acylinder carried bythel outer core barrel, a piston reciprocably mounted in said cylinder and carrying said inner core barrel, said cylinder being of restricted diameter at its upper end and the pistonhaving a portion of reduced diameter extending through said restricted portion oi the cylinder, the cylinder being Aopen to expose the under surface ot the piston, means for supplying a fluid under pressure toboth the upper and lower surfaces ot the piston to eiiect an upward movement of the piston and the inner core'barrel due to the diilerential eiiect 'or the pressure applied land suspend the inner core barrel, and means associated with the cylinder intermediate the upper 'and lower piston surfaces providing a chamber containing a compressibie medium to oppose outer core barrel, an inner core barrel; a cylinder carried by the f outer corebarrel, a piston reciprocably mounted in. said cylinder `andfcarrying said. inner core non-restricted portion of the piston and the restricted portion of the cylin-` the lower end ofA upward movement of so c. scimmie;`

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