US2642141A - Collapsible packer for well instruments - Google Patents

Description

.lu-ne 16, 1953 4 R, H, KQLB 2,642,141

COLLAPSIBLE PACKER F03 INSTRUMENTS Filed Aug. 3l, 1951 Fu. l lBY; S

HIS. ATToRNaY Patented June 16, 19753 ooLLAPsTLE PAoKER Fon WELL INSTRUMENTS Robert H. lI {jol/b, Houston, Tex., assigner to Shellv Development Company, Vcorporation of Delaware Emeryville, Calif.,

Application August 31, 19,51, Serial No. ,2444498 4 Claims. (o1. rse-#10) This invention relates to paokrs for usein Swell .boreholes and ypertains more particularly to collapsible packers for use with rin'strur'nents employed in oil Wells, forexample, Well instruments adapted'to be lowered-into a well borehole, [casing ortubing on a wire line.

The packers presently used on 'Wire line instruments have certain drawbacks and are considerably limited in vtheir application, thus often decreasing the f vflexibility and usefulness of the instrumenten which they are mounted. For example, the expansion of most packers 'i's limited to Yabout twice their collapsed vdiameter or the diameter'ofthemandrfel on which they may `be mounted. Thus, `in lorder 'to `employ a packer vcapable fof Vsealing on fa large-diameter borehole or well casi-ng it is necessary to yuse afpacker having a large diameter lin its collapsed position. Most packers halve an additional disadvantage finthat they are capable of being actuated l'(or setin a flxedposition Va Well borehole) only once .with-out removing the instrument and'its l `lpacker from thewell and V resetting vthe packer.

While a few packers are adapted tto be moved Y and re-actuated several times `when the instrument on `which the 'packer is mounted jis 'runV into the Well. or 'Withdrawn therefrom, there is at present no packer which Vmay 'be actuated, 'retracted and then Ares'et at several locations as it is moved both and down in a Acas'edjor un'- cased Vwell borehole.

It is therefore a primaryobjject of this-inventionto provide an improved packerl-foruse with o a Well instrument, which packer is' capable r4of beingreset `at any desired number of locations infa cased or uncased Well rborehole asl-the inzstruinent is run in and/or out of the well.V

`,Another ob'je'ot of the present invention is to provide a collapsible packer adapted Ttojbe run through 'a small diameter rproduction tubing Yin either" direction while remaining in its retracted position. l v

Aiur'ther object 'of this invention istoprovide acollapsible packer contained tWithin a housing adapted to be unhouse-d and-'expanded 'as it t-lleg'eS from the lower d 'O'fV a vpilfocru'oti'0n tubing and capable of being automatically-'revtracted Within its housing las it again -ent'ers the tubing.

Another object of the #present invention is 'to provide a readily collapsible packer yforus'eon a wire line well instrument, 'said packer Vbeing rcapable 'of expanding to several 'times its lapsed diameter.' y

'further objectof this invention 'isjtoprovide a collapsible packer for well instruments oi small diameter capableoi passing .through a well vprod'u'ct'i'on tubing, saidjpacker being adapted to be automatically setV upon emergence from the end of the vtubing, .in a larger-diameter portion ofa well. y

These and other objectsy of this `invention will be understood' Vfrom the following description taken with wherein:

Figure 1 Vis a longitudinal view of -the lpresent Well packer in its retracted or collapsed position when attached t'o the lower end of ja Well instrument 'and'positioned Within a Well tubing;

zll-iure 2 'is Aa longitudinal view, partly in cross se'cti'on,'of the present 'well packer in its operreference 'to the attached drawing,

ative or expanded position when located in `a well bore or casing;

Figure 3 Vis a side view 'offthe ,atching mechanisms k3B and 131i shown in Figure 42.

ligurejl` is ja plan view of the latching mechanism of Figure 3 taken along line 4,-4 of Figure 2. Referring toFigure 1 of the drawing, 'thepresent well Vpacker 'IVI 'is illustrated in its retracted position in 'a fwell tubing 'l2 'together with Aa Well 'instrument 'I3 removably secured in any lsuitable manner Vto the upper end of said packer.

Theh'present packer 4comprises 'a tubular body member l5 having 'a 'coupling I4 at its upper end Vjfor attachment to a coupling yHla on 'the lower end of fthe 'well 'instrument lf3, as shown in Figure '2. `While the bodymember VI5 may lbe a isinglegtubular elementgit is preferred for ease of assembling the "present packer that the body ffember be vmade of two tubular :pieces AI5 and [Eijjoined togetherY by a coupling l1. 1

secured-to the lower encor the tubular 'body lr'nembe'r I6, 'in anvsuitable manner, is a cone- 'Sl-l'al'p'd element Which will hereinafter 'burelferredto 'asthe vparachute `vt8.k Theapex of the y conejor `the rcenter of `the parachute lris open allowing 'lfluid [to .pass from the parachute up through 'the tubular Vbody members l5 and IB landmip linto meten-'instrument l's. The `p'a'ra'- t chute "isfpre'ferably made of "any suitable thin ilexiblev material such as rubber, synthetic rub-- ber, Vrubberized jlc'anvas, Vfoanvas, plastid-metallic cloth or scr'een, etc. Additionally the parachute may comprise ja plurality of relatively thin petallike segments' of-metal or Iplastic material, "the contiguous 'edges-of said segments circumferen- /tially overlapping 1when-the packer lis in` its Sexpanded 'or actuated position.

A Therapex'of the parachute I t8 'is suitably seicur'edin a Sfixed manner to the lower end 'oftubular body member I6, as by a ring clamp I9.

'tube or sleeve 26.

Fixedly secured to the outside of the tubular body member I3, or to the ring clamp I3, are a plurality of parachute ribs 2B which reinforce the parachute in its extended position, as shown in Figure 2, and aid in folding the parachute into its retracted position. The ribs are preferably made of spring-steel wire or narrow metallic bands which may be provided with fixed rings 2| to which the lower edge of the parachute may be secured.

The lower ends of the ribs 2 Vare welded or otherwise fixedly attached to a ring 22 which is slidably mounted on a guide rod or extension shaft 23. The guide rod 23 inV turn is affixed by one or more thin vanes 24 to the lower end of the tubular body member i6. The spaces -between the vanes 24 allows uid to pass around the end of the rod 23 and into the bore of tubei6. A stop member 25 aixed to the rod 23 limits the upward movement vof the slidable ring 22.

Mounted for sliding coaxial movement on the tubular body member I5 is a parachute housing Preferably the sleeve 26 has an inside diameter greater than the outside diameter of the body member I5 whereby an an nular space 21 is formed between the two elements. Formed or afdxed on the top ofthe sleeve 26 is a bearing 28 in sliding contact with the outer wall of the body member I5. At least one port 3'I is providedthrough the sleeve 25 near the top thereof to allow the escape of fluid which may become trapped within the sleeve. The outside diameter of the coupling I1 is preierably substantially equal to the inside diam-eter of the sleeve .25 whereby the outer face orv wall of the coupling IT acts as a bearing surface for the lower end of the sleeve 26. It is to be realized, however, that the tubular body member I5 may be constructed as a single element with its outer surface acting as the bearing surface for a close-fitting parachute housing sleeve '26.

The housing sleeve 23 is ,of a length such that Vthe vparachute is entirely covered when the packer isin its retracted position, as shown in Figure l. The guide rod 23 extending for some distancebelow the body members I5 and is of a diameter substantially smaller than the bore of the housing sleeve 26 whereby the parachute are mounted on the packer assembly. The Y upper ends of the springs 29 are ixedly secured lin any suitable manner, as by welding or clamping, to the housing sleeve 2S'while the lower ends of the springs are alxed to a centraliser slide 3U mountedl for movement along rod 23.

The slide 3i) is equipped with latch means 3| adapted to slide radially and seat in a groove 32 in the rod 23 near the lower end thereof. One form of latch means is illustrated in Figures i. to 4 wherein "the latch. 3| comprises dovetailed bar members slidably mounted on either side of rod 23 in a dovetailed slot 3|a. (Figure 3) in the top of the'slid-e 30. One spring 29 passes through each end of the latch means 3| and is ancho-red on slide 3B. The springs 29 are secured to the latch means 3| so as tol springload the latch means whereby said latch means disengages the groove 32 when the `centralizer springs are allowed to expand outwardly against the walls of a well casing 33, as illustrated in Figure 2. I

. I8 may be folded and contained within the space I As shown in Figure l, the wall of the housing sleeve 26 is provided with a series of longitudinal slots 34 equal in number to centra-lizer springs 29 and in alignment therewith. The slots 34 are wider than the springs 29 thus allowing offsets in the springs, as at numeral 35, to extend into said slots and seat against fthe shoulder formed by the top of the coupling I'I. The operation of the centralizer springs 23 will be described hereinbelow. IThe springs 29 are of a length such as to. extend from the coupling I'| to a point well below the parachute it and its ribs 20. Preferably, the centralizer springs are formedy ord'esigned so that a substantial length of each spring 29 is in fractional contact with the inner wall yof the well casing 33 when the packer assembly is in its operative position.

In operation, the present packer assembly may be attached to the lower end of various types of well instruments for packing oi a well casing and directing the production well fluid through the well instrument. For example, the present packer assembly may be 'attached to the lower end of a well fiowmeter as described in U. S. Patent No. 2,593,285 to Fay et al.

Prior to insertion of the packer assembly and well instrument into a lubricator at the well head or into thev top oi the tubing string I2, the parachute "ribs 2Q are collapsed with the parachute I8 folded within them and the parachute housing sleeve 25 is lowered over the parachute I8 and ribs 2Q so as torestrain them from opening. The centralizer springs 29 are then collapsed and manually'held in a collapsed state. As the centralizer springs 29 are collapsed, the slide 3E) and its latch 3| are forced down the rod 23 until the latch 3| engages the groove 32 in the lower end of the rod 23. As long as the walls of the tubing i2 as shownin Figure l, the latch means 3| engages groove 32 'and prevents the spring 29 and the Vhousing sleeve 25 attached thereto from moving upwardlyand unhousing the parachute I8. In this condition, thepresent packer assembly i i may be lowered through the tubing without danger of the packer closing the bore of the. tubing I2 and interfering with the production of oil therethrough. At the same time the parachute I8, being within the housing sleeve 2S, is protected from damage by abrasion against the tubing wall while `being lowered through the tubing i2.

When the packer assembly I I passes out of the lower end ofthe tubing I2, as illustrated in Figure 2,the centraliser springs 29 expand and disengage the latch `3I from the groove 32 on rod 23. Frictional contact between the centralizer springs 29 and the well wall, or the wall of the casing 33, causes the housing sleeve 2li, attached to the springs 29, to be moved upwardly along the tubular body member l5, lthus unhousing the parachute -|8. n

Upon reaching the depth in the well at which an instrument reading is tobe taken, the lowering of the instrumenta-nd packer assembly is stopped and the combined appara-tus is raised for pulled upwar ly Ya few feet. Reversed wall friction on thecentralizer springs causes the housing sleeve 26 to be forced downwardly relative to the parachute I8. Downward movement of the housing sleeve'i on body member I5 is limited by the latchmeans formed by the offsets 35 in the centralizersprings 29 which extend through slots 34 and Lcome to bear on the *aman shoulder formed by the top .of coupling I1. 'With the housing sleeve 26 in this position thelargest diameter of the cage formed by the bowed centralizer springs 29 is located opposite the largest diameter of the parachute I8 'which is at this f time able to contact the inner wall of the well casing. Due to the exib'ility of both the para.-

chute I8 with its ribs 20 and the springs' 29,

the vanes 24., up the tubular body membersli and I6, and up into -the well instrument* vIn testing a well, it vis oftendesirable to move the well instrument up and downfin the well-borehole or well casing33,r and take -readings ata. Plurality of stations. of the `present packeris that it is designed to be readily moved either upward or downward in a well borehole. To lower the .instrument and its packer from one location rto another, tension is released on the cable by which theinstrument is suspended, `and the weight ,of the instrument I3 moves the tubularbody `members 'I5 .and I6 and the parachute IS downwardly. At the same time wall friction on the centralizer springs 29 causes them to remain substantially stationary so that the parachute is wedged into the tapered lower section of the centralizer and is partially collapsed. 'I'his allows iiuid to pass around the lower edges of the parachute and 'permits rapid lowering of the instrument, while the parachute is removed from abrasive contact with well wall.

Whenfa tnew test location has 'been reached, the packer is again pulled upward a few feet so the centralizer springs 29 move downward with regard thereto until the oiTsets 35 in thesprings stop in operating position once more against the collar I'I. Readings may be taken at as many stations as desired with the instrument I3 and packer II traversing the well borehole any desired number of times in either or both directions. The operation of the packer is not adversely affected by the raising or the lowering of the combined instrument and packer. When the instrument is being One of the .great advantages raised in the well the parachute collapses partially due to the downward pressure of the well fluid on the top of the parachute, and a clearance is provided between the parachute I8 and the well casing 33 for any well fluid to be by-passed around the parachute packer. At the same time, the parachute is removed from abrasive Contact with well walls.

When the instrument and packer is to be removedfrom the well through a tubing string, it is pulled upwardly until the open lower end of the tubing I2 contacts the nearly perpendicular upper portions of the centralizer springs 29 at 29a.. A continued upward pull on the instrument causes the centralizer spring 29 to collapse. It will be seen from the drawings that the shape of the springs 29 is such that the bending to which they are subjected in collapsing causes them to pivot about a point 36 (Fig. 1) on the housing sleeve 26 a short distance below the slots 34. n The collapsing centralizer springs 29 begin' partially to collapse and to fold the parachute I8.

This pivoting action, upon continued raising of the springs 29 into the tubing I2, causes the offsets 35 to spring out of their respective slots 34,

thus'freeing the. hcusing'sleeve 26 which moves j downwardly to ollapse'andsurround the paravchute I8 andr its -ribs 20, Further collapsing of the centralizer springs 29 causes them to extend axially downwards, thus mov-ing the slide 30 down rod `23 until latch 3| again engages the groove 3-2. The parachute assembly remains latched as long as the centralizer springs are held in a retracted `position vby the tubing I2. The packer II, in its retracted vposition shown in Fig. 1., can be withdrawn through the tubing I2 without interfering with thecontinuous production of iiuid therethrough,A lThe springs 29 space the retracted packer in 'the center of the tubing I2 allowing the flow of fluid past it and eliminating any swabbing action within the tubing by the packer. At the same time the parachute I8 is encased in the y housing sleeve k26 and is thus protected Vvfrom abrasion on the walls of the tubing.

I claim as. my invention:

l; lA wellpacker assembly Vadapted to be lowered through a well tubing, comprising a tubular jbody member, a rod co-aXiajlly secured to the lower en d of saidV body member, said rod having a diameter substantially smaller than said body member, a radially expansible parachute packer .axially mounted on saidbojdy member, said parachute packer in its retracted position being folded about said rod, a housing nsleeve lslidably mounted on said body member., Said Sleeve beine adapted .to Surroundk Said parachute packer and 'hold Said packer in its retracted nasition during .both the Vlowering and raising operation, and y,radially ex..

substantially smaller than said body member, a

radially. expansible parachute packer axially mounted on said body member, said parachute packer in its -retracted position being folded downwardly about said rod, a plurality of flexible metallic reinforcing ribs aixed at one end to the body member and extending radially and downwardly about the parachute packer, a housing sleeve slidably mounted on said body member, said sleeve being adapted to surround said parachute packer and ribs and hold said packer and ribs in their retracted position during the lowering operation, and radially expansible centralizer spring means carried outwardly on said housing sleeve, said spring means developing a suiiicient friction force against the well walls to free said parachute packer from said housing sleeve when the entire packer assembly is moved out of the lower end of the well tubing.

3. A packer assembly adapted to be lowered through a well tubing suspended within a well casing, said packer assembly comprising an elongated tubular body member having open ends, a guide rod co-axially affixed to and extending from the lower end of said body member, fluid port y end of said body member, said parachute packer opening downwardly whereby the sides of the parachute engage the walls of the well casing when said packer is actuated, a plurality of flexible metallic reinforcing ribs axed at one end to the lower end of the body member above said parachute packer, said ribs extending radially and downwardly along the top surface of the packer for reinforcing said parachute packer against the upward thrustof a well iiuid, an elongated housing sleeve slidably mounted in a cri-axial manner on said body member for alternately covering and uncovering the parachute packer and the reinforcing ribs when said packer is alternately in its inoperative and operative positions, and centralizer kmeans comprising a plurality of bow springs affixed at their upper ends to the housing sleeve above the parachute packer and at their lower ends to a slidable member mounted on said guide rod below said parachute packer, said bow springs being radially expansible from said housing sleeve and guide rod for frietionally engaging the wall of the well casing whereby the housing sleeve is removed from the parachute packer on further lowering of the packer assembly.

4. A packer assembly adapted to be lowered through a well tubing suspended within a well casing, said packer assembly comprising an elongated tubular body member having open ends, a guide rod co-axially axed-to and extending from the lower end of said body member, fluid port means about the upper end of said rodand in communication with the bore of said body member, said rod being of smaller diameter than said body member, a radially expansible parachute packer of a thin impervious flexible material carried on said body member, the central portion oi said parachute packer being secured to the lower end of said body member, said parachute packer opening downwardly whereby the sides of the parachute engage the walls of the well casing 8 when said packer is actuated, a plurality of ilexible metallic reinforcing ribs aixed at one end to the lower end oi the body member above said parachute packer, said ribs extending radially and downwardly along the top surface of the packer for reinforcing said parachute packer against the upward thrust of a Well fluid, an elongated housing sleeve slidably mounted in a co-axial manner on said body Vmember for alternately covering and uncovering the parachute 'packer and the reinforcing ribs when said packer is alternately in its inoperative and operative positions, centralizer means comprising a plurality of bow springs affixed at their upper ends to the housing sleeve above the parachute packer and at their lower ends to a slidable member mounted on said guide rod below said parachute packer, said bow springs being radially expansible from said housing sleeve and guide rod for frictionally engaging the wall of the well casing whereby the housing sleeve is removed from the parachute packer on further lowering of the packer assembly after the springs have engaged the casing wall, stop means carried by the housing sleeve for limiting the downward movement of said sleeve when the parachute packer is in its eX- panded position, and latch means caried by the slidable member for engaging the lower end of the guide rod to retain the centralizer springs in a retracted position as the packer assembly passes through a well tubing.

ROBERT H. KOLB.

References Cited in the file of this patent UNITED STATES PATENTS Burt Sept. 20, 1949

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