US2652232A

US2652232A - Core recovery indicating device

Info

Publication number: US2652232A
Application number: US298781A
Authority: US
Inventors: Jr Hal H Holland
Original assignee: Standard Oil Development Co
Current assignee: Standard Oil Development Co
Priority date: 1952-07-14
Filing date: 1952-07-14
Publication date: 1953-09-15
Anticipated expiration: 1970-09-15

Description

Patented Sept. 15, 1953 Hal Haflolland; J r.,,6or y mesne assignmen pus Christig-Texaassignor, ts, to Standard: Oil Devel opment Company, Elizabeth, N. J., a, corporatlon'of Delaware Application July 14, 1952, Serial no, 298,781

8 Claims.

ingwhiol t:

Fig: L is an elevation, artly in section, showing an embodiment of the core barrel in position in the drill stem for receiving a core;

Fig. 2- is an enlarged fragmentary View; partly in section; showing further details of constructiono! the embodiment of Fig; 1;

Fig; 2A is a view in section taken along the. line 2A-2A of Fig; 2; and,

Fig. 3 is an. enlarged fragmentary view similar to Fig. 2 showing another embodiment of the present invention.

Turning now specifically to the drawing and first to Fig. I, a conventional drill bitA mounted in the lower end 015 drill stem B is shown in posi-' tion for cutting a core at the bottom of a borehole C'.

I e" principal parts of the core barrel shown -D with a packer tion of barrel D has moiznteet on its interior a vertically arranged series ofstops K designated 5 6; 7 8, and 9 ofs rogressively decreasing diam-- eterrin' the upward direction.

Cooperating with series of stops are dogs In the drawing the parts of latch assembly F shown are clogs I 6 and retriev'ahl'e spear head' member [1. Since such latchesare WEIF known to the art, of construction have been omitted 111 order to a pluralitiy'oi'. spaced longitudinally extending slots I 5.

2. Within the barrel D is mounted the circular ing a suitable recess into which spring I3 is arranged to bias dogs i2 outwai'dly into contact with. graduated stops KL Plate 20 is also provideo withslips 20a so as to allow only upward movement of assembly G.

25 having a central passage" with packing ring 26 which embraces and packs off rod 22" of assembly GFa-t-a" point between piston Ll and lower plate 20. Partition 2?, in elfect, divides core barrel D into progressively'decreasmgthe area of fiOW.- In the the annulus becore barrel into the slots, it is desirable to provide a fluid passage from the part of the annulus above packer E to that part below packer E to facilitate the withdrawal oi the core barrel assembly. In the embodiment of Figs. inasmuch as the packer E is mounted on the exterior of the barrel and piston 2| makes contact with the interior of the barrel, thus the thickness of the wall of barrel D allows slots IE to serve as passages even if the upper end of plunger 2! is at the same level as packer E. When piston 25 is raised so that its lower end is past the lower end of slots it an increased flow area is provided by passageways 24 of piston 25 as will later be explained.

The two springs J and I3 are proportioned so that a change in the effective length of J is suincient to cause a predetermined change in the efiective length of l3. Thus, as spring J is cornpressed by core l8 entering the barrel, the plunger assembly G moves upwardly compressing spring l3 and causing the dogs ii to move in turn past the stops I I.

In using the device of the present invention it may either be dropped down the drill stem and then retrieved with a sand line after a core has been cut or alternatively may be lowered on the end of a sand line. In any event, it assumes the position shown in Fig. 1 when in core cutting position. The interior mechanism is initially arranged with plunger assembly G in a lower position with clogs ii in contact with the lowermost stop of the graduated stops l2. The interior of the barrel is, of course, free from a core so that circular plate H is in its lowermost position and spring J is in its extended position. In the position of plunger assembly G described, the upper wall of piston 2! is below the lower ends of longitudinal slots I5.

In cutting the core, the drill stem is rotated and drilling fluid is pumped downwardly through the drill stem in the usual manner. When the drilling fluid reaches the point in the drill collar where the core barrel assembly i arranged, it flows in the annular space between the outer wall of barrel D and the inner wall of drill stem 13 until it reaches packer E where it is forced to flow through slots into barrel D, then downwardly in the flow passage between the wall of barrel D and rod 22, then outwardly through the lower portion of slots [5 and downwardly in the annular space between the outer wall of barrel D and inner surface of drill stem B and then through the mud courses 10 of the drill bit. The mud then flows upwardly in the usual manner between the outer wall of drill stem D and the wall of borehole C.

As core 5% is cut it necessarily forces circular plate II upwardly in order to enter the core barrel. This upward movement of plate H in turn causes spring J to compress. Since springs J and spring l3 are selected to have a predetermined relationship, the compression of spring J a certain initial amount causes such a force to be exerted through plunger assembly G as to compress spring 13 and move it past stop 5, which is the lowermost series of stops K. Upon movement of plunger assembly G, piston 2| of the assembly is forced upwardly until its upper end is above the lower portion of longitudinal slot [5 thus reducing the amount of flow area for the drillin fluid and causing an indication at the surface by an increase of pump pressure in the mud pumps. As additional core enters the barrel D, plate II is forced upwardly an additional amount, in turn additionally compressing spring J and when this compression exceeds a predetermined amount the dogs 12 are pushed past stop 6, the second stop of the series of stops K, piston 2| moving upwardly and further reducing the flow area of slots l5 and causing another increase of pump pressure.

The device as shown is proportioned such that as dogs l2 move upwardly against

stop members

5, 6, and 1 piston 2| progressively reduces the flow area of slots is thus causing three stepwise increases in mud pressure. However, in the embodiment shown, when the dogs I2 reach this position, the upper end of piston 2! has moved up even with the lower end of packer E so that the pump pressure remains substantially constant while dogs I2 move along stop member a. Further upward movement of piston 21 (at which time dogs l2 are in contact with stop 9) causes the lower end of piston 2! to rise above the lower end of slot 15 and fluid may flow through passages 24 of the piston and out through the exposed lower portions of slot l5 which will cause a reduction in pump pressure. Summarizing, the five stepwise movements along stops 5, 6, 1, 8, and 9 result in three stepwise increases in pump pressure, then a step where the pump pressure remains constant and a. final step where the pump pressure decreases. When the pump pressure decreases or drops suddenly (the final step) this is an indication to the operator that the desired amount of core is in the core barrel. At this point the lower end of piston 2! is above the lower ends of slots It, thus affording a bypass for the flow of mud around cup packer E which allows the entire assembly to be easily withdrawn.

It will be understood that if difilculty is encountered during the coring operations so that core is not entering the barrel, the stepwise increases in mud pump pressure will not occur, and this will indicate to the drilling crew that some correction of the coring operation should be made. Thus, the device of the present invention enables a signal to be transmitted to the drilling crew at the surface at the time a core is being cut in the borehole so that it is unnecessary to withdraw the core barrel in order to determine whether or not the attempt to take the core is successful.

When the core barrel is to be removed from the drill stem, as when a core has been cut, it may be removed in the usual manner with a sand line.

As a further embodiment of the present invention, instead of a single series of longitudinal slots 15, two series of longitudinal slots, an upper series and a lower series, may be used. Such an embodiment is shown in a fragmentary View in Fig. 3. In Fig. 3 barrel D is provided with an upper series of longitudinal slots 36 arranged above packer E and a lower series of longitudinal slots 3i below packer E. This embodiment will operate in exactly the same way as in the embodiment of Figs. l and 2 except that bypass passages are not provided adjacent cup packer E for flow of fluid.

From the description of the present invention, it will be seen that I have provided a retrievable core barrel having a construction which causes stepwise changes in pressure in the mud pump as a core enters the core barrel during the cutting of a core. Thus, the crew is provided with a signal which indicates the success of the coring operation.

While I have disclosed specific embodiments of drill stem for the passage. of drilling mud, said barrel having a partition to divide it into a lower compartment fluidly sealed from an upper compartment and having alt-least one longitudinally extending slot in its wall above said partition, re-- leasab'le latching means mounted on said barrel for latching it to said drill stem, a packing mentber mounted on said barrel in such a way that at least aportion of said longitudinally extending slot is exposed below said packing member, a longitudinally movable slide valve member mounted in the upper compartment in slidable sealing contact with the inner wall of said barrel and arranged to be moved longitudinally from a first position to a second position in which more of the slot area below the packing member iscovered than in said first position, a contacting in the lower end of said barrel in the lower compartment adapted to be forcausingsaid slide valve member to move from its'first position to'its second position upon longitudinalm'oveinent of said contacting member,

partition; a packing member mounted on said barrel in such a way that at least aportion of said" longitudinally extending slot is exposed be lowsaid packing member,

second pos tion in which more of the slot areal below the: packing member is covered" than in said first position, a contacting member'slidably fitting in the lower end. of said barrel. adapted to be pushed. upwardly asthe core enters said.

slide valve member to aocaaaa trail passage to divide 1 meat:

" :the upper compartment in slidinner wall of said moved longitudinally upwardly as the core enters the barrel, a, rod passing? through: the central passage of said par.-

titi'on and mechanically linking said contacting partment from the lower compartment.

4.. A core barrel for use in a drill stem adsaid barrel having a lower compartment,

compartment adapted to be pushed upwardly as the core enters said barrel, a linkage mechanically connecting said contacting of said contacting member and carrying dogs arranged to make contact with said series of stops! and a. spring member. operatively arranged to bias said dogs into contact with said stops.

5; A core" barrel for use in a drill stem adjain combination, an barrel adapted to fit loosely in clearance between the outer surface of the barrel and the inner surface of the passage of drilling mud, said barrel having apartition to divide it into a lower-compartment. fluidly sealed from an upper compartmentat least one longitudinally extending slot in its wall above said partition and a; longitudinally arranged series of stopsof pro-- gressively differing diameter carried by the inner wall of said barrel, releasable latching means mounted. on said barrel for latching it to said drill stem, a packing member mounted on said barrel in such a way that at least a portion of said longitudinally extending slot is exposed below said packing member, a longitudinally movable slide valve member mounted in the upper compartment in slidable sealing contact with the inner wall of said barrel and arranged to be moved longitudinally from a first position to a second position in which more of the area of the slots below the packing member is covered than in said first position, a contacting member slidably fitting in the lower end of said barrel in the lower compartment adapted to be pushed upwardly as the core enters said barrel, a linkage mechanically connecting said contacting member with said slide valve for causing said slide valve member to move from its first position to its second position upon longitudinal movement of said contacting member and carrying dogs arranged to make contact with said series of stops, a first spring member operatively arranged to bias said dogs in contact with said stops and a second spring member operatively arranged between said contacting member and said plunger member, said first and second spring members bearing such a relationship that a predetermined change in the efiective length of said second spring member causes a predetermined change in the effective length of the first spring member whereby a progressive upward movement of said contacting member causes a predetermined and smaller longitudinal movement of said plunger assembly.

6. A core barrel for use in a drill stem adjacent a drill bit comprising, in combination, an elongated tubular barrel adapted to fit loosely in the drill stem with clearance between the outer surface of the barrel and the inner surface of the drill stem for the passage of drilling mud, said barrel having a partition pierced by a central passage to divide it into a lower compartment and an upper compartment and having a plurality of circumferentially spaced longitudinally extending slots in its'wall above said partition and a longitudinally arranged series of stops of progressively differing diameter carried by the inner wall of said barrel, releasable latching means mounted on said barrel for latching it to the drill stem, a packing member mounted on said barrel in such a way that at least a portion of each of said longitudinally extending slots are exposed below said packing member, a contacting member slidably fitting in the lower end of said barrel in the lower compartment adapted to be pushed upwardly as the core enters said barrel, a plunger assembly mounted in said barrel for slidable 1ongitudinal movement including a cylindrical slide valve member mounted in the upper compartment in slidable sealing contact with the inner wall of said barrel and arranged to be moved longitudinally from a first position to a second position in which more of the area of each of the slots below the packing member is covered than in said first position, and a rod passing through the central opening of the partition and extending into said lower compartment and having dogs mounted thereon arranged to make contact with said series of stops, a sealing member carried by the partition making a fluid-tight seal with said rod portion of the plunger assembly for sealing the lower compartment fluidly from the upper compartment, a first spring member operatively arranged to bias said dogs into contact with said stops, a second spring member operatively arranged between said contacting member and said plunger assembly, said first and second spring members bearing such a relationship that a predetermined change in the effective length of the second spring member causes a predetermined change in the effective length of the first spring member whereby a progressive upward movement of said contacting member causes a predetermined and smaller longitudinal movement of said plunger assembly.

'7. A core barrel for use in a drill stem adjacent a drill bit comprising, in combination, an elongated tubular barrel adapted to fit loosely in the drill stem with clearance between the outer surface of the barrel and the inner surface of the drill stem for the passage of drilling mud, said barrel having at least one longitudinally extending slot in its wall and a longitudinally arranged series of stops of progressively differ ing diameter carried by the inner wall of said barrel, releasable latching means mounted on said barrel for latching it to said drill stem, a packing member mounted on the slotted portion of said barrel for making contact with the inner wall of said drill stem and of such dimensions that at least a portion of a longitudinally extending slot extends above and at least a portion of a longitudinally extending slot extends below said packing member, a contacting member slidably fitting in the lower end of said barrel adapted to be pushed upwardly as the core enters said barrel, a plunger assembly mounted in said barrel and including a valve member having a cylindrical imperforate wall in slidable sealing contact with the inner wall of said barrel and arranged to be moved longitudinally from a first position to a second position in which more of said slot area is covered than in said first position, said plunger assembly having dogs arranged to make contact with said series of stops, a first spring member operatively arranged to bias said dogs into contact with said stops, a second spring member operatively arranged between said contacting member and said plunger member, said first and second spring. members bearing such a relationship that a predetermined change in the effective length of the second spring member causes a predetermined change in the effective length of the first spring member whereby a progressive upward movement of said contacting member causes a predetermined and smaller longitudinal movement of said plunger assembly.

8. A core barrel for use in a drill stem adjacent a drill bit, comprising in combination, an elongated tubular barrel adapted to fit loosely in the drill stem with clearance between the outer surface of the barrel and the inner surface of the drill stem for passage of drilling mud, said barrel having a partition pierced by a passage to divide it into a lower compartment and an upper compartment and having at least one opening in its side wall above said partition, a packing member mounted on said barrel in such a way that at least a portion of said opening in the side wall is exposed below said packing member, a movable valve member mounted in the upper compartment in slidable sealing contact with the inner wall of said barrel and arranged to be moved from a first position to a second position in which more of the area of said position upon longitudinal movement of said opening in the side wall below the packing contacting member. member is covered than in said first position, a HAL H. HOLLAND, JR.

end of said barrel in the lower compartment 5 References Cited in the file of this patent adapted to be pushed upwardly as the core en- UNITED STATES PATENTS ters said barrel and a linkage mechanically con- Number N D t necting said contacting member with said slide 2,145,191 Pennington Jan. 24, 1939 valve member for causing said slide valve mem- 2,213,595 Salnikov Sept. 3, 1940 her to move from its first position to its second 10 2,613,918 Long Oct. 14, 1952