US2163813A - Oil well packing head - Google Patents

Description

June 27, 1939- F. STONE ET AL OIL WELL PACKING HEAD Filed Aug. 24, 1956 4 Sheets-Sheet l Inventor: J iederick Sfon .Hlberl L.S0ne.

Attorney.

June 27,

1939. F. STONE ET AL OIL WELL PACKING HEAD Filed Aug. 24, 1956 4 Sheets-Sheet 2 lflvenians. fiederidlrfitone. eri L. tone.

F, STONE 51' AL 2,163,813

HEAD

June 27, 1939.

OIL WELL PACKING 4 Sheets-Sheet 3 Filed Aug. 24, 1936 Patented June 27, 1939 UNITED STATES PATENT OFFICE OIL WELL PACKING HEAD Frederick Stone, Torrance, and Albert L. Stone,

Palos Verdes Estates, Calif., assignors to Hydrii Company, Los Angeles, Calif" a corporation of California.

Application August 24, 1936, Serial No. 97,632 17 Claims. (Cl. 180-14) This invention has to do with oil well packing tlon. For purposes of describing certain aspects heads, used for the purpose of sealing around drill of the invention, as will later appear, the packing pipe or other work extending through the head head in this view is shown to take a drive stem of into the well pipe, and particularly with improvepolygonal cross section. ments in packing heads 01' the type disclosed in Figs. 4 and 5 are sectional views taken on lines Patent No. 2,038,140, issued April 21, 1938, on 4-4 and 55, respectlveiy,of Fig. 3;

Packing head, and in our copending application, Fig. 6 is a fragmentary enlargement of the check Ser. No. 50,482, filed November 19, 1935, on Packvalve in the vent passage leading from the chaming head. ber above the main packer; l0 In the present type of packing head, a radially Figs. 7 and 8 are fragmentary enlarged views m contractible packer is pressed into engagement showing a portion of the indicator mechanism in with the work by a contracter, preferably in the changed positions; form of a piston, that is movable vertically within Fig. 9 is a sectional view showing another form the housing. Various aspects of the invention of packing head embodying the invention; and l are conveniently applicable to packing heads of Fig. 10 is a fragmentary enlarged view of the a this type in which the packer contracting piston is indicator piston in Fig. 9. actuated by fluid pressure, although it is to be In the typical and illustrative form of the understood that in certain of its broad aspects, the invention shown in Fig. 1, a pa 0! Packing heads invention is not to be regarded as limited to pack- Ill and H are shown to be mounted in tandem ing heads in which the packer is piston actuated, arra t a e th w p p or casing the or, where a packer actuating piston is used, to one individual packing heads and their connections operated by fluid pressure. Without going into forming a general head assembly l3 adapted to detail at this point, it may be stated that the maintain a fluid tight seal about the drill pipe or main objects of the invention are directed to other Work during drilling Op t ons. OI While improvements in the packer construction and e p p is going into 011% Of e We 8-11 in the mounting, adjustable stop control means for the manner later to be described in detail. Heads l0 packer contracting piston, and t ariou 1 and II, while generally similar, have certain difprovemcnts in the construction, arrangement and ferences in construction and operation that adapt control of packing heads in tandem arrang ent. them t their particular functions in e p operating to maintain a fluid tight seal about the tion of the head assembly 3- In des the work as it is being lowered into or withdrawn from construction of the two packing heads, reference 80 the well. first will be made to their common structural All these generally stated purposes of the invenfeatures, using the same reference characters for tion, as well as various other features and objects, corresponding parts, and then to the structural will be most readily understood and explained to aspects in which the heads are differentiated. best advantage without further preliminary dls- The lower head II is attached to the well cascussion, from the following detailed description of me l2, and upp r hea to a P l4 intercon- Lhc invention in one of its typical and preferred fl e g e tWO heads, y up ngs l5 havin forms. Reference is had throughout the descripthreaded box ends l5a receiving the threaded ends m tion to the accompanying drawings, in which: of the pipes. Each packing head comprises a 0 Fig. 1 is a general view, in elevation, showing a tubular b y us ng It hav g a ower reduced typical emb diment of the invention ri i diameter bore I1 and a counterbore it, there being pair of packing heads in tandem arrangement, a downwardly tapering shoulder I9 between the certain of the connections therewith being shown two bores. A tubular head 20 having a bore 2| diagrammatically; and a threaded counterbore 22, is threaded at 21 5 Fig. 2 is a longitudinal sectional view of the into the upper end of the housing. Although the upper packing head illustrated in Fig. 1, the. main head 29 i5 apfl 0f Vertical l t e 1! packer being shown in radially constricted posiany reason such adjustment is found desirable, it tion; I will ordinarily be screwed fully down to seat on Fig. 2a is a fragmentary section as viewed on body shoulder 24. Fluid leakage from within the 50 line lit-4a of Fig. 3, but showing the packer com housing aroun the head is Prevented y ab e pressed into engagement with the flat surfaces of means, such as a packing ring 25. the drive stem; The tubular head 20 conveniently provides a Fig. 3 shows the lower packing head in longimounting for a radially compressible rubber tudinal section, with the packer in released posipacker 26 preferably in the form of a continuous 5 annular sleeve normally having a substantially uniform diameter bore 21 with beveled surfaces at 28 and so, see Fig. 3, an outer and upper cylindric surface ill, and a downwardly tapering or conical surface ll. The upper end of the packer sleeve is supported by the lower tubular portion of the head 20. One of the important features of the invention is an improved connection between the support and packer that will withstand, without damage to either the connection or packer, the various distortions to which the latter may be subjected under conditions of operation under high pressure. As illustrated in Fig. 2. the packer sleeve in its constricted condition. is deflected inwardly about the work, for example the drill pipe 82. Under extreme well pressures, the packer may be forced upwardly within space 33 between pipe 32 and the bore II, a distance considerably above the position shown. The result is that the packer is subjected to severe shearing stress at the lower edge Ila of bore 2!, as well as to an inward radial strain tending to shear the upper surface 28a of the packer from its mounting. This inward radial distortion of the upper end of the packer extends, though to a progressively lessening degree, to its outer periphery. Thus the radially inward deflection and distortion of the packer resulting from its being forced up into the space 33, is least within the outer portion indicated at N.

The packer mounting, generally indicated at 35, comprises a ring I that preferably is removably attached to the tubular head 10 by suitable means, as for example by pins 31, see Fig. 5, inserted within bores ll extending through the ring and intersecting the head Ill. As will be apparent, these pins may be driven out of the bores to disconnect the ring II. The packer 26 is connected to and suspended from the mounting 35 by a continuously annular fabric material 39. which may be formed in multiple ply or by a suitable number of separate fabric layers, embedded within the packer and extending downwardly and inwardly within the rubber at the outer portion 84. The upper and inwardly turned portion of the fabric is clamped between ring I and ring ll attached to the former by screws I. The top surface Ila of the packer bears against the bottom surfaces of ring it and head 28 which are provided with annular ridges, and into the spaces between which the rubber flows when the packer is subjected to upward compression. These ridged surfaces of the ring and head act to form an extremely strong bond with the packer for the reason that as the rubber is forced into the inter-ridge spaces, the air is expelled from the spaces, and thereafter the fluid pressure in the head tightly holds the rubber to the metal surfacm. An annular, double lipped packing 42 prevents any fluid that might leak outwardly between the lower end of head 20 and the packer. from escaping past ring 36. The packer sleeve is internally reenforced at its upper end by suitable flexible reenforcing material, preferably layers of fabric 43, embedded in the rubber and extending horizontally inwardly and then downwardly below the bottom of surface ll.

As will be understood from the foregoing, the fabric It connecting the packer with the mounting is advantageously positioned to withstand the most severe usage and distortion of the packer, by reason of its being embedded in the outer portion ll of the rubber at which the least deflection and distortion of the packer occurs. Tear-- ing and stripping of the rubber from the packer, as might otherwise result from rotation of the drill pipe with the packer rubber forced upwardly in space I8, is effectively prevented by the reenforcing fabric 43, and the fact that the latter is extended inwardly and downwardly adjacent the packer bore where the wear and stresses on the rubber are the greatest. We have previously explained how at times the combination of radial contraction of the packer and well pressure applied thereto will force the rubber upwardly within space 33 and cause greater displacement or movement of the rubber at the inner surface of the packer support than toward the peripheral portion thereof. The feature of locating the fabric attachment ll within the outer interior of the packer is of great importance in that the fabric thus is removed from the inner portion of the rubber subjected to greatest distortion and where the tendency of the rubber to become sheared from its support is greatest, with the result that the fabric is not subjected to bending and shearing strains that otherwise might be suflicient to rupture it and thereby sever the packer from its support. It will be understood that materials other than fabric may be utilized in the arrangement illustrated, to support and reenforce the packer, although fabric is preferred because of its inherent flexibility and rubber bonding qualities.

The packer contracting piston 45 has upper and lower portions a and Nb of diiferential diameters corresponding to the diameters of the housing bores I8 and I1, respectively, the piston having a sliding fit within the housing and carrying suitable packing rings 48 to prevent fluid leakage. The angularity of the intermediate tapered portion 41 of the piston is somewhat greater than the angularity oi the housing shoulder ll, so as to provide an annular space at 48 between the piston and housing, for the introduction of pressure fluid for purposes later to be explained. In its lowermost position, see Fig. 3, the piston seats on annular surface 50, the angularity of which corresponds to the taper of the piston surface 41.

The contracter 4! has a bore ll of substantially the same taper as surface 3! of the packer, so that as the contracter moves upwardly relative to the packer, it acts to constrict the latter radially inward against the work 32. The relative positions of the contracter 45 and packer 28 in constricted condition, are illustrated in Fig. 2, wherein the rubber is shown to be compressed against the pipe 32 with the upper bore surface 28, beveled to prevent tearing, of the packer forced inwardly at the bottom of space 31.

The lower depending portion of the tubular head 20 is spaced at 53 from the wall of the housing to provide an annular chamber containing a ring 54 that is attached to the contracter piston and forms with it, what may be termed the piston assembly. As illustrated in Fig. 5, ring 54 is detachabiy secured to the top of the contracter piston, by means of removable pins 55 inserted within open end bores 58 terminating in piston ll and intersecting ring 54. The latter carries suitable packing means 51 sealing the piston against downward fluid leakage. The purpose of ring ll primarily is to communicate to piston 45 the pressure of fluid introduced to chamber 53, as will later be explained. It will suflice to state at this point that as a result of fluid pressure applied to ring 54, the contracter I is moved downwardly from the position c! Fig. 2 to that of Fig. 3, to release the packer from the work. A vent passage II is formed in the upper portion of the contracter I for the purpose oi releasing irom space ll below ring Bl, any operating fluid that might leak past the piston into space 8| and otherwise tend to resist downward movement or the piston assembly. Vent passage II communicates at its lower end with chamber II and with space it by way of port ill, see Fig. 8, controlled by a spring pressed check valve ii. The valve unseats to pass fluid from space SI into chamber ll as the piston assembly moves downward, and at other times is held in seated position by the spring 62 to prevent return flow or the pressure fluid from chamber 49.

Adjustable stop means, generally indicated at 63, is provided for the purpose of limiting the upward travel of the piston assembly, and also to limit the degree to which the packer is constricted about the work in the uppermost position of the piston, independently of the amount of fluid pressure being exerted upwardly against the piston to compress the packer. In one form the adjustable stop means comprises a plurality of circularly arranged set screws 64 extending through the head and a packing retaining ring into space 53. Individual packing rings 8 prevent leakage of the high pressure fluid around the set screws. Normally, screws 64 will be set to limit the upward travel of the piston assembly at a point to which packer 26 will be constricted about the work with sufllcient tightness to prevent any considerable upward leakage of fluid, but at the same time to permit just enough fluid leakage through the packer to lubricate its engagement with the work. This type or adiustable piston stop is disclosed in the earlier flied application referred to above. The present invention constitutes an improvement in the stop means in that it provides means for the simultaneous adjustment of all the individual set screws 54, as by the adjustment or any one of them, thus obviating the necessity for adjusting each set screw, and assuring that the screws will be adjusted to exactly the same vertical positions.

Each of the set screws 84 carries a sprocket 68 meshing with a circularly continuous chain 89, see Fig. 4, contained within and tightened against the base of an annular groove l0 formed within rings II and 12. These rings are secured together by screws 13 and are supported on the annular shoulder 14 of a ring 15 resting on sprockets 58 and through which the upper ends of the set screws project. Rings Ii and I! serve as a floating carrier for the chain 6!, the rings in the lower head H extending loosely about the pipe I4 and similarly, in the upper head ill, about a nipple l6 threaded into counterbore 22 of memher I'll. As will be apparent, by adiusting any individual set screw Bl, all the other set screws whose sprockets 88 are meshed with the chain 69, are correspondingly adjusted in the same direction and to the same degree.

The upper head It is constructed to operate automatically as a blow out preventer, and in this respect its structure differs in certain respects from the construction of the lower head i i. The packing contracter piston 45 in the upper head is made automatically responsive to sudden increases in the well pipe pressure so as to auto matically constrlct the packer about the drill pipe, by means of a second packer, generally indicated at 18, carried within the lower portion of the piston 45. This lower packer ll preferably will be made to maintain a fairly tight fluid seal between the piston 45 and the drill pipe, although some leakage past the packer ll may occur without disturbing its eirectiveness as a blow out preventer, since the packer and constrictor assembly will necessarily be actuated when a blow out occurs, because oi the great volume or well fluid released under high pressure. Thus packer I8 serves primarily to provide sufliclent seal or restriction about the work that will cause a more or less sudden increase of fluid pressure in the pipe II to raise the piston l5 and constrict the upper packer 26.

Packer I8 comprises a rubber sleeve vulcanized to an outer cylindric tube ll inserted within the piston counter-bore t2, tube ll having clearance at I from the bore wall and at 8 from the shoulder at the top of the counterbore so as to be freely rotatable together with the packer, within the piston. The packer is supported on a retaining ring 84 threaded into the lower end of bore 82 and held in place by set screw 8. The bottom or the packer extends outwardly below the lower end of tube Bi and is provided with an annular lip "2 adapted to be forced outwardly by fluid pressure into sealing engagement with the wall of bore 82. The packer 80 is moulded about a perforated reenforcing metal tube iii, the rubber filling the tube perforations 85a to eflectiveiy integrate the metal tube with the rubber body in such manner that the former will hold the rubber from flowing" or gathering as the pipe collar 32a passes through. The rubber packer 80 has an inwardly projecting annular lip 86 engaging the outer surface of the pipe and having a downwardly inclined upper surface 81 and a lower substantially flat or slightly inclined suriace 88.

It is desired to taper the top surface 81 of the packing lip in order to facilitate downwar passage of the pipe collar through the packing against pressure in pipe It. By virtue of its shape, lip 85 is reenforced against and made relatively resistant to upward deflection by fluid pressure or by the pipe collar, so as to effectively withstand any severe conditions of wear that might result from repeatedly pulling the collars through it as the pipe string is elevated. The packer lip however offers less resistance to downward movement of the pipe collars through it,

since the lip will more readily deflect in a down direction. Upon engagement by the collar, the lip is doubled upwardly or downwardly, in accordance with the direction of collar movement, into the spaces at 89 and 90 proportioned to afford ample clearance between the packing and collar to accommodate deflection of the lip.

The lower packing head II is provided below the piston 45 with a vertically movable pipe contacting means, generally indicated at 9|, that operates as a part of a signalling system for indicating the upward passage of the pipe collars Ila past a predetermined pont below the packer constricting piston, during withdrawal of the drill pipe from the well. The vertically displaceable means indicated at BI is to be regarded merely as typical of various suitable devices that are upwardly displaceable upon engagement by the pipe collar, and capable of actuating the later described parts of the signalling system. In its preferred form, the device 9! comprises a cylindric ring 9! slidably engaging bores 94 and 95 of the head and coupling I 5, respectively, and having its outer surface channeled at 93 to reduce frictional contact with the bore walls. Normally, and

in its lowermost position, ring 92 seats on an 75 annular shoulder 90, the ring assembly being shown elevated from its seat in Fig. 3 merely for purposes of illustration and description. Clamped between the upper portion 92a of the ring and a retaining ring 91 threaded into its lower end, is a perforated tube 90 carrying a plurality of circularly spaced rubber lugs 98 molded integrally with the tube and project'ng inwardly to an extent that they will be engaged by the pipe collar 320 as the drill string is elevated. Preferably, in order to prevent the ring from becoming untimely raised as a result of contact between the rubber lugs and the pipe between couplings, the lugs will have the maximum clearance from the outside surface of the pipe 32 (assuming the work in Fig. 3 to consist of a circular drill pipe), that can be maintained and yet have the lugs engaged by the pipe collar with suflicient tightness to raise the ring. Rings 92 and 91 may contain circularly spaced openings I00 and IM to provide space, in addition to the spaces between the rubber lugs, for fluid to pass through the ring without the fluid flow being restricted to the extent that the ring assembly will be elevated by fluid pressure alone. In case the pipe is rotating with the collar in engagement with the lugs, tube 98 and the lugs, or the entire ring assembly, may rotate within the housing.

Upward movement of ring 92 past a predetermined point operates a suitable signal actuating device, typically of the character indicated generally at I02, and shown in detail in Figs. 7 and 8. The device I02 comprises a laterally displaceable tubular piston I03 including an enlarged diameter head portion I04 contained within the housing bore I05, and a tubular stem portion I06 movable longitudinally within the bore of fitting I01 threaded into the housing counterbore I08. The piston head I04 contains a check valve I00 which is normally seated by coil spring IIO to prevent leakage through opening III of the pressure communicating fluid contained in the signalling system. The piston normally is thrust outwardly to project the rounded end of the head I04 into the housing bore 90 by coil spring II2, the inward position of the piston being determined by engagement of the enlarged end lIIGa of the head with shoulder Ill at the end of the fitting bore H5.

The lateral or vertical pressure acting against the piston I03 is balanced by communicating the well pressure via space I030 and opening I03b, to annular grooves I03a in the piston, the groove at the left also connecting opening I031) with chamber I03d.

The fitting I01 is connected with a suitable pressure indicator or gage Ili, see Fig. l, by pipe 1, and the pipe, fitting and piston I00, all are filled with a suitable pressure communieating fluid, for example a rather heavy but flowable oil, so that outward displacement of the piston from the position of Fig. 7 to that of Fig. 8, will develop fluid pressure in line III that is indicated by the gage Hi. The system may be charged with the oil in any suitable manner, as by introducing the oil through a fitting IIO below the gage, and holding the check valve I09 open with the piston positioned as in Fig. '7, until oil discharges through opening ill, indicating that all the passages between the valve and gage are filled with oil. Preferably, line III will be charged with fluid at a pressure greater than the casing fluid pressure, to insure against the piston being forced outwardly by the well pressure. Should the fluid pressure in the signaling system tend to drop below well pressure, check valve I09 will open to balance the pressures. Figs. 7 and 8 indicate the two positions of the indicator piston I03 before and after engagement by the outwardly inclined surface 921; of the ring 92, as the latter is elevated by the engagement of collar 22a with the rubber lugs 99. As the ring moves up, surface 921) cams the piston I03 to the position of Fig. 8, developing a pressure in line III that is indicated on the gage IIB. Ring 92 is limited in its upward position of Fig. 8 by engagement with suitable stop means, for example circularly spaced screws S projecting into the housing bore 24 at a level permitting cam surface 92b to travel upward while in engagement with the piston, a distance sufficient to cause the piston to communicate a pressure impulse, but limiting the upward travel of the ring assembly so that after the pipe collar has passed through, the piston still will engage the cam surf ace. Thereupon, the ring assembly may drop by gravity to its lower position.

Referring now to Fig. l, the upper and lower packing heads are interconnected by tie bolts B 20 in the lower packing head. The packer contracting pistons in the heads I0 and II are operated by pressure fluid that may be derived from any suitable source via line H9, or from the well casing I! through line I20. The pressure fluid is supplied to the piston chambers in the two heads via line I2I which is communicable, under control of a four way valve I22, with chambers 53 and 49 in the upper head I0 via pipes I23 and I24, respectively, and with the corresponding chambers in the lower head II by way of lines I26 and I26, under control of four way valve I21. As the contracter pistons are moved vertically, fluid from one or the other of chambers 49 and 53, depending upon the direction of piston movement, is exhausted through lines I28 and I29.

Referring to Fig. 2, it will be noted that the piston assembly, including piston 45 and ring 54, provides an upwardly facing pressure area, the top surface of ring 54 exposed to chamber 53, and two downwardly facing pressure areas, the tapered surface 41 of piston 45. and the lower end of this piston including the area of packer 18 between the bore of the retaining ring 04 and the outside of pipe 32. These pressure areas. of the piston assembly may be conveniently designated in the order named, as P1, P2 and P3. As illustrated, the combined areas of P: and P3 is greater than the area P1. but P1 is greater than either P2 or P3, although it is only of importance that P1 be greater than P3.

Advantage is taken of the differential pressure areas of the piston assembly as a means whereby the packer 26 may be released from the work, while at the same time releasing movement of the contracter is resisted by the fluid pressure within the casing I2 acting against pressure area P3 of the piston. Referring to Fig. 1, assuming line I2I to be in communication with line I20 connecting with the casing, by reversing the position of valve I22 to connect the discharge pipe i20 with space 49 via line I24, the well pressure is applied through line I23 and chamber 53 against the upper pressure area P1 of the piston assembly. As stated before, the area Pi is greater than P3, and with the pressure exhausted from space Ill, the unbalanced pressure on areas Pr and P; results in downward movement of the contracter and release of the packer 26 from the work.

As will be understood, only a single packing head may be used to maintain a seal about the work and to serve as a blow out preventer, without necessitating the use of the illustrated dual tandem arrangement that has the added utility of enabling a seal to be maintained while lowering or removing the drill pipe. To illustrate the operation of a single packing head, for example the upper head III, the packer in the lower head may be assumed to be released from the drill pipe and valve I30, Fig. 1, closed to render the lower head inoperative. To illustrate the operation of the upper head when the well starts to flow, as for example during drilling or at any other time when the packer "normally is open, assume the parts to be in the positions of Fig. i

I with valve IBI closed and valve I32 opened, the

pipe II! to be connected with a source ofpressure fluid, for example with the circulating fluid pumps, .not shown. Valve I22 is thrown to the position illustrated to communicate the pressure fluid to chamber l9 and to relieve pressure from chamber 52 above the piston. With the packer in this position, the pipe 32 may be rotated and moved back and forth between the collars during the operation of conditioning the circulating mud in the well to the point where the flow is under control. Then the packer may be released by reversing valve I22 to communicate the fluid pressure to chamber 53 and ex- .haust the pressure from chamber it. when the packer contracter is independently controlled and operated by fluid pressure from line H9 as just explained, the lower packer 18 need not necessarily be used, as the operator has full control in the event of sudden development of pressure in the well.

Fig. 3 illustrates the adaptability of the piston actuated packer to seal about work of polygonal cross section, for example an octagonal drive stem or kelly 32b. The packer also is capable of sealing about drive stems of other cross sectional shapes, the octagonal form being shown as typical. The fact that our improved packing head can maintain a substantially fluid-tight seal about a polygonal cross section drive stem rotating within the packer, is of great advantage and importance in that the necessity for the usual relatively complicated and expensive devices employed to seal of! around the drive stem, is obviated in favor of a single and relatively simple packer sleeve capable of sealing around allowing a restricted leakage of fluid through the packer to lubricate its engagement with the drive stem surfaces. Lubrication is essential in i order for the rubber to withstand the wear and the packer about the drive stem, pressure fluid is introduced to chamber 4!, causing the piston to raise and constrict the packer into engagement with the flat surfaces of the drive stem as shown in Fig. 20. Movement of the piston in a packer contracting direction, and therefore the extent of packer contraction, are limited by proper adiustment or stop screws 84, to permit a slight upward leakage oi well fluid through the packer for the purpose, as stated, of lubricating its contact with the drivestem. Tests have demonstrated that under these conditions, the packer is capable of maintaining, except for the slight leakage, a seal about the drive stem over long periods of operation.

To understand the operation of the two packing heads Ill and II, assume that the drill pipe 32 is being pulled from the well, and that the packer 26 in the upper head is closed about the pipe as shown in Fig. 2, with the packer in the lower head in the released position of Fig. 3. Assuming the well to be under pressure, valve I32 may be closed and valve Ill opened to supply pressure fluid to line I2i from the casing I2. Generally speaking, the two packing heads are operated to pass successive pipe couplings 32a without loosening the fluid seal around the pipe, by keeping the upper head I! closed until the coupling passes above the packer 26 in the lower head II, after which the latter is closed and the packer in the upper head opened, to permit the collar to pass on through. The described signalling system is used to control the operation of the heads, since it indicates the position of the pipe collar with relation to the lower packer and enables the operator to determine when the coupling has passed through the lower packer, so that the latter may be closed and the upper packer opened.

Thus, as the collar 32a engages and elevates the ring assembly 9|, the signalling system indicates the position of the collar by pressure increase on the gage Iii resulting from outward displacement of the piston I03, all in the manner previously explained. By observing the movement of drill pipe extending above the upper head III the operator is able to visually gauge the distance that the coupling 22a must travel to move up through the packer in the lower head. At that point, valves I22 and I21 are reversed, causing the packer in the lower head to close about the pipe below the coupling, and the packer in the upper head to open for the purpose of passing the coupling.

As will be understood without the necessity of further and repetitious explanation, the upper and lower packing heads are operated in a reversed sequence while drill pipe is being lowered into the well. As the pipe goes into the well, the position of the coupling with relation to the packer in the upper head, is gauged by reference to the top portion of the housing, the described signalling system being used only during withdrawal of the pipe.

Fig. 9 shows a variational form of packing head similar in general respects to the type illustrated in Fig. 3, but differing principally in the particular form of piston stop adjusting means, the arrangement, relative to the packet, of the signal actuating device, and the construction of the main packer. Parts that are the same as those previously described are given the same reference characters. In this variant form, the vertically movable stop pins I35, slidable longitudinally within bores I38 in the head 20', are adjustable by means of a rotatable ring I21 provided with sockets I38 to receive a manipulating tool, and threaded at I55 on an upper tubular extension I of the housing screwed into bore I of member 25. The housing extension I45 has an interior work centering flange I42 presenting a downwardly and inwardly inclined surface I43, and a bottom shoulder I44 that serves as a stop for the signal actuating ring assembly I45. The upper ends of pins I35 are received within an annular groove I45 in the bottom face of ring I31.

In the drawings, the stop pins I35 are shown to be maintained in raised position by frictional engagement with the individual packers I41, As will be apparent, by rotating ring I31, the stop pins may be maintained in diiferent but corresponding positions of adjustment relative to the packer and its actuating piston.

In Fig. 9, the plunger actuating ring assembly I45 is movable vertically within bore I45 between shoulder I44 and shoulder I49 of the head 25'. The construction 01' the ring assembly is generally similar to the previously described form, excepting that the packing I5Il is more nearly the internal diameter of the outer sleeve I5I, and the rubber lugs I52 have square cut under-shoulders I53 that are engaged by the couplings as the pipe string is elevated.

The piston, generally indicated at I54, differs from the form shown in Figs. '1 and 8, principally in that the pressure of fluid in line II1, alone is utilized to maintain the plunger in its projected position, the spring being eliminated. The rounded plunger head I55 contains a bore I55 through which fluid pressure is communicated from within the housing to chamber I51; the sides of the piston being flattened at I55 to establish open communication between the chamber and transverse bores I55 connecting with bore I55. The piston is thrust into the housing bore to a limiting position determined by the engagement of the piston carried lugs I with bushing IN, by fluid pressure applied at the outer end of rod I 52 sealed around by suitable packing I53. Upward movement of ring I5I by the pipe collar to position of engagement with shoulder I44 thrusts the piston outwardly, developing an indicated pressure in line II1. After the collar passes through the rubber lugs, the fluid pressure against piston rod I52 returns the piston to the position illustrated, causing the rounded piston nose to cam ring I5I downwardly.

In Fig, 9 we have shown, in addition to the check valve 5| past which fluid is released from chamber 59 through passage 55, a second pressure relief passage formed by a bore I54 in portion 54 of the piston, and controlled by downwardly seating spring pressed check valve I55. This second pressure relief passage and valve are provided as a means of permitting the piston to move downwardly to its lowermost position, in the event passage 55 should for any reason become clogged against fluid escape therethrough. Assuming passage 55 to be closed, as the piston moves downwardly, check valve I55 will unseat and pass fluid from space 55 to chamber 53 at the point at which the pressure in 55 starts to exceed the pressure in 55. The piston will then continue its downward travel, despite the communication between the two chambers, by reason 01' the larger pressure area P1 exposed to the upper chamber.

The main packer I55 has a substantially cylindric bore I51, and an annular lip I55 projecting inwardly from the bore wall. Broadly speaking lip I58 may have any suitable shape, although preferably it is so formed that while in engagement with the work, as it normally is, the lip is more resistant to upward deflection than to downward deflection. Typically, the lip may be formed with an upper, downwardly and inwardly inclined surface I55, and a lower surface "I! of comparatively less angularity in a downward and outward direction. so as to render the lip less resistant to downward deflection. By reason of its under surface being cavitated as at I", the lip is less resistant to downward deflection because of the removal at "I of rubber that would otherwise reenforce the lip against downward deflection. comparatively, the lip is more resistant to upward deflection by reason of the reenforcement afforded by the rubber at I12. The outer surface of the packer has an annular cavity I13 substantially opposite the lip I55 to provide a space into which the rubber may flow or expand when the packer is contracted.

Lip I55 is itself capable of providing a fluidtight seal about the pipe 52, without contracting the packer from the position shown, at such times as the casing pressure is comparatively low, for example not in excess of 300 pounds per square inch. The lip is maintained in sealing engagement with the surface of the pipe by the upwardly applied fluid pressure, and by reason of its shape characteristics, the lip is sufflciently resistant to upward deflection that it will hold the pressure. As the pipe contacting surface of the lip becomes worn, the piston may be raised willciently to compensate for such wear by radially compressing the packer and lip, stops I35 being adjusted, if desired, to limit the piston travel. By virtue of its reenforced characteristics, the lip will withstand repeated passage of pipe collars upwardly through it, and, after the passage of each collar, the lip will return to its illustrated position of sealing engagement with the pipe. As the pipe string is being lowered through the packer, the lip will deflect downwardly to pass the collars, without becoming appreciably worn.

In the event the well develops comparatively high pressures that the lip I55 will not hold, the packer may be bodily contracted about the pipe to bring the packer bore I51 into sealing engagement therewith. Upon radial contraction of the packer, the lip, relatively, will be forced in the body of the packer and the rubber will expand into cavity I13 to compensate for the lip displacement. It is important to observe that even though the lip should be severely worn, even to the point of severance from the body of the packer, the latter still may be contracted about the pipe to maintain a fluid-tight seal.

We claim:

1. In a packing head for well pipe, a tubular housing adapted to take work through its bore, the walls of the housing forming a closed space, radially contractible packing in the housing and about the work, a member movable to contract the packing, a plurality of movable stops extending within said space and engageable by said member in its packing contracting movement, and means for adjustably moving said stops simultaneously relative to the housing and packing and said contractlng member.

2. In a packing head for well pipe, a tubular housing adapted to take work through its bore, the walls of the housing forming a closed space, radially contractible packing in the housing and about the work, a member movable to contract the packing, a plurality of movable stops exenamels tending through the wall 0! the housing into said space and engageabie by said member in its packing contracting movement, and an adjustable member movable relative to said housing and maintaining said stops in diiierent but corresponding positions of adjustment relative to the packing and said-contracting means.

3. In a packing head for well pipe, a tubular housing adapted to take work through its bore, said housing containing a closed space, radially contractible packing in the housing and about the work, a fluid pressure actuated piston ior contracting the packing, means for introducing fluid to said space to actuate the piston, a plurality of movable stops extending'within said space and engageable by said piston in its packing contracting movement, and adjustable means movable relative to said housirm and operable to maintain said stops in diilerent but corresponding positions 01' adjustment relative to the packing and said contracting member.

4. In a packing head for well pipe, a tubular housing adapted to take work through its bore, radially contractible packing in the housing and about the work, a fluid pressure actuated piston for contracting the packing, a plurality of movable stops engageable by said piston in its packing contracting movement, and an annular and rotatably adjustable means coasting with.

said stops to position them in different but corresponding positions of adjustment relative to said packing and contracting means.

5. In a packing head applied to a well pipe. a

tubular housing adapted to take an elongated member through its bore, a radially contractible packer in the housing and about the work, a packer support, a packer contracting piston movable upwardly within the housing by fluid pressure to constrict the packer about said member, said piston and support enclosing a chamber about the packer, means forming a fluid vent passage leading from said chamber, a check valve preventing return flow or fluid through said passage into the chamber, and means for moving said piston vertically by fluid pressure.

6. In a packing head for well pipe, a housing, a tubular packer within the housing and adapted to take work through its bore. a portion of the packer bore wail normally being spaced about the work, an annular lip projecting inwardly from said portion of the bore wall and engaging said work to seal around it, and a fluid pressure actuated tubular piston surrounding said packer and operating to press said normally spaced portion of the packer bore wall into engagement with said work, the outside of said packer within the piston being recessed to accommodate outward displacement of the packer material as the packer is contracted about the work.

7. In a packing head applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractible packing in the housing and about the pipe, means for contracting the packing about the pipe, means actuated by fluid pressure for indicating vertical movement of the pipe collar to a predetermined position relative to the packer, and an annular pipe surrounding member displaceable vertically by engagement with a pipe collar for actuating the last mentioned means,

8. In a packing head applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractible packing in the housing and about the pipe, means for contracting the packing about the pipe, a member movable laterally by virtue 01' vertical movement of the pipe collar, fluid pressure actuated means indicating lateral movement oi said member, and an annular pipe surrounding member displaceable vertically, by engagement with a pipe collar for actuating the last mentioned means,

9. In a packing head applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractible packing in the housing and about the pipe, means for contracting the packing about the pipe, an indicator, a line charged with fluid under pressure at least as great as the well casing pressure, and means actuated by virtue of pipe collar movement for communicating pressure to the fluid in said line, the last mentioned means including an annular pipe surrounding member displaceable vertically by engagement with a pipe collar. A

10. In a. packing head applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractlble packing in the housing and about the pipe, means for contracting the packing about the pipe, a vertically movable annular member surrounding the pipe and adapted to pass the pipe collar, said member being upwardly displaceable when engaged by the pipe collar, and means indicating upward movement of said member.

11. In a packing hea'd applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractibie tubular packing in the housing and about the pipe, means for contracting the packing about the pipe, a vertically movable member surrounding the pipe, and centering the pipe relative to said packing, said member being adapted to pass the pipe collar and being upwardly displaceable when engaged by the pipe collar, and means indicating upward movement of said member.

12. In a packing head applied to a well casing, a tubular housing adapted to take collared pipe through its bore, radially contractible packing in the housing and about the pipe, means for con tracting the packing about the pipe, an annular member surrounding the pipe and adapted to pass the pipe collar, yieldable means carried by said member and engageable by a pipe collar, said member being upwardly displaceable upon engagement of said yielding means by the pipe collar, and means indicating upward movement of said member.

13. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a tubular packer, a support for one end of the packer, a packer contracting piston movable toward said support to axially compress and radically contract the packer about the work, the inner portion of the packer adjacent said support being displaceable, when the packer is radially contracted, into a space between said support and the work, and fabric embedded in the packer and having a projecting end portion attached to said support, said fabric being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

14. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer, a support for one end of the packer, a packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being displaceable, when the packer is radially contracted, into a space between said support and the work and continuously annular fabric embedded in the packer and having a projecting end portion attached to said support, said fabric being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

15. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer having a longitudinally tapered surface, a support for one end of the packer, a tapered bore packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being dispiaceable, when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion attached to said support, said fabric extending longitudinally and inwardly within the packer from its point of attachment to the support and being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

16. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer, a support for one end of the packer, a packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being displaceable. when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion, an annular member clamping said projecting end portion of the fabric to said support, said fabric being spaced substantially further from the packer bore than from the outside oi the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

17. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer having a longitudinally tapered surface, a support for one end of the packer, a tapered bore packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being displaceable, when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion, an annular member against which the end of the packer bears, for clamping said projecting end portion of the fabric to said support, said fabric extending longitudinally and inwardly within the packer from its point of attachment to the support and being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

FREDERICK STONE. ALBERT L. STONE.

CERTIFICATE OF CORRECTION.

Patent No. 2, 165 ,815.

June 27 1959.

FREDERICK STONE, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, sec- 0nd column, lines 65 and 7h, claims 1 and 2 respectively, after the word "member" insert exposed to said space and; and that the said Letters Patout should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of September, A. D. 1939.

(Seal) Henry Van Arsdale,

Acting Commissioner of Patents.

the work, the inner portion of the packer adjacent said support being displaceable, when the packer is radially contracted, into a space between said support and the work and continuously annular fabric embedded in the packer and having a projecting end portion attached to said support, said fabric being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

15. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer having a longitudinally tapered surface, a support for one end of the packer, a tapered bore packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being dispiaceable, when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion attached to said support, said fabric extending longitudinally and inwardly within the packer from its point of attachment to the support and being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

16. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer, a support for one end of the packer, a packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being displaceable. when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion, an annular member clamping said projecting end portion of the fabric to said support, said fabric being spaced substantially further from the packer bore than from the outside oi the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

17. A packing head for well pipe comprising a tubular body adapted to take work through its bore, a continuously annular packer having a longitudinally tapered surface, a support for one end of the packer, a tapered bore packer contracting piston movable toward said support to axially compress and radially contract the packer about the work, the inner portion of the packer adjacent said support being displaceable, when the packer is radially contracted, into a space between said support and the work, and continuously annular fabric embedded in the packer and having a projecting end portion, an annular member against which the end of the packer bears, for clamping said projecting end portion of the fabric to said support, said fabric extending longitudinally and inwardly within the packer from its point of attachment to the support and being spaced substantially further from the packer bore than from the outside of the packer so as to permit said displacement of the inner portion of the packer adjacent the support without subjecting said end portion of the fabric to rupture by bending and shearing strains.

FREDERICK STONE. ALBERT L. STONE.

CERTIFICATE OF CORRECTION.

Patent No. 2, 165 ,815.

June 27 1959.

FREDERICK STONE, ET AL.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 6, sec- 0nd column, lines 65 and 7h, claims 1 and 2 respectively, after the word "member" insert exposed to said space and; and that the said Letters Patout should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 5th day of September, A. D. 1939.

(Seal) Henry Van Arsdale,

Acting Commissioner of Patents.

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