March 8, 1960
`
`T. B. DELLINGER
`WELL HEAD BYPASS ASSEMBLY
`
`Filed Sept. 21, 1955
`
`2,927,643
`
`61
`
`CASING BOWL
`CASING HANGER
`CASING
`FIG.-2
`PACKER ASSEMBLY
`17
`Thomas B. Dellinger
`Inventor
`FIG-/
`B& t:f. ~ Attorney
`
`GREENE’S ENERGY 1006
`
`000001
`
`

`

`Unite.cl States Patent Office
`
`2,927,643
`Patented -Mar. 8, 196.0
`
`1
`
`2,927,643
`
`WELL HEAD BYPASS ASSEMBLY
`Thomas B. Dellinger, Tia Juana, Zulia, Venezuela, as(cid:173)
`signor, by mesne assignments, to Jersey Prodnction
`Research :company
`
`Application September 21, 19-55, Serial No. 535,64'5
`5 Cfalms. (CI. 166-75)
`
`2
`invention by the use of meiuis for bypassing the well. head
`assembly of a well an:d for isolating the well head as(cid:173)
`sembly .from the pressures that exist within the well dur•
`.More spe•
`ing the time of excessive injedive pressures.
`5 cifically, the invention makes use of an elongated chigh
`pressure conduit which extends from a point below the
`casing head and within the production tubing of :a well
`to a point vertically beyond and -above the well head
`assembly. The conduit rs selected iii size_._i.e., diam~
`10 eter-such that it may be inserted within .the .pfoducfion
`tubing by lowering it . vertically :through .the wen :head
`assembly.
`At. its lower end the conduit is provided with .a packer
`assembly of a type particularly adapted. for movement
`IS through the well head assembly and for. sealing off that
`portion of the production tubing which lies vertically
`below the packer assembly from the well ·head appa(cid:173)
`ratus. The upper end of the conduifis secured to and
`is sealed within a hold-down flange which in turn'.is se•
`20. cured .to a fixed support, preferably the well head assem(cid:173)
`bly itseif. The upper end of the bypass conduit is .further
`provided with a high pressure valve and any other ap~
`paratus which would be conventionally requiretl for in~
`troducing or withdrawing fluid within the well:
`The invention may be better understood by .reference
`to the attached figures wherein-
`Fig. Lis a vertical, partially cross-sectioned view ,of
`a well head assembly which · has . incorporated therein an
`embodiment of the invention.
`Fig. 2 is a view in cross section of a packer assembly
`which has been constructed and .used as a component
`part of the apparatus illustrated ,in Fig. J.
`Turning first to Fig. 1, t)lere is illustrated a .conventional
`type of well .· head assembly ·including a .casing .head
`35 flange ·10, tubing hanger 11, tubing . head flange .u, .a
`master valve l3, a cross 14, a top valve 1s;· 1ubricator
`connection 16, production tubing 17 and casing l8. ,Als.o
`illustrated in the figure are _bypass conduit 5, combina~
`tion blow-out preventer and stuffing ·box 4, liolddown
`40 assembly 3, valve ,2, ·cable members 6, hoisting mem(cid:173)
`bers 7, packer assembly .S, casing bowl 30, hanger 31
`and wing valves 20 and 21. . ...
`·
`In discussing the apparatus of ·Fig. I, :it will be .un.der(cid:173)
`stood that. the well head apparatus '.is installed at the
`45 surface of a conventional, cased well and that the casing
`head ·10 is secured in a conventional manner to a .flange
`on casing bowl.30 in which casing :hanger 3L(equipped
`v/ith the ustial slips and pack off seals) ·holds the .casing
`siispended and seals the pressure ·to within the casing
`50 and the well head.
`.
`It will further be understood in Figure 1 . that ,the
`various flanges are oolted or welded.together .in a conven(cid:173)
`tional manner. The flanges in the figure are actually
`spaced slightly apart for ~he .sake of Clarity and :ease 6f
`55 illustratfon.
`Attached to the casing head assembly 10 are two con·
`ventional wing valves 20 and 21 such as might be em(cid:173)
`ployed for injecting and wi.thdrawing fluid from the · an(cid:173)
`iitilar space between the tubing and the casing. Also .in-
`60 chided within casing head assembly 10 is ·tubing 'hanger
`11 which may be of a · conventional type normally em(cid:173)
`ployed for supporting the .production tubing 17. The pr.O·
`duction 'tubing itself extends from ti.thing head flange
`12 'down irito the well to one · or more producing forma-
`65 tions not shOwn. As in the case of the casing head as~
`sembly and the tubing. hanger, the production tllbi11g
`may be conventionally selected from any of the sizes
`and types of tubing that are usually employed in .oH .
`well operations.
`.
`'
`.
`.
`· . .
`.
`.. · .
`The upper.end of the production tubing 17 may be
`conventionally threaded or otherwise . secured . and seal~d
`within · the ' tubing head 1.2 'as illustrated. · Tub1ng 'heaa
`
`The present invention •generally . relates to an auxiliary
`and temporarily placed well head construction wherein
`th_e various components of a permanent well head are
`isolated from the pressures existing within the well. The
`inv.ention is particularly concerned with apparatus useful
`in conjunction with well formation fracturing processes
`or other treating operations where the pressures involved
`are beyond the safe operating limits of the permanent
`well head apparatus. The invention further relates to
`apparatus which permits for fracturing, acidizing or other(cid:173)
`wise treating subterranean well fonnations without the 25
`necessity for altering or changing the valves, fittings and
`the . like that form components of the . permanent well
`head. The invention has application to oil wells and
`gas wells and also to injection wells.
`In applying fracturing techniques to oil wells, it . is 30
`c£ten .necessary to replace the : well head equipment .on
`the wells before the fracturing may take place. This
`change in well head equipment is occasioned by the ·fact
`that the equipment in many instances possesses too low
`a pressure rating for the Pf.essures that are involved in
`tbe fracturing operation. Thus, it is very common . in
`producing areas where the formation and well ·pressures
`are relatively low to use valves and other fittings in the
`well head assemblies which are rated ·for 2000 p.s.i.g. or
`even less.
`Inasmuch . a.s most Ji;acturing operations re(cid:173)
`quire operating pressures of at least 4000 p.s.i.g. and
`sometimes as much as 7000 p.s.i.g., it follows that change
`of the well head equipment is a necessary step, especially
`from a safety standpoint, . before a . fracturing operation
`can proceed. Such a change requires that a workover
`rig be moved into the well and often necessitates killing
`the -well and making a trip with the production tubing,
`rendering it a costly and time-consuming operation.
`With :these shortcomiiigs of the presently employed
`conventional techniques of formation fracturing in mind,
`it : is. an objective .· of the ,present invention to take ad(cid:173)
`yantage of . high pressure fracturing operations in wells
`that possess low pressure well head apparatus without
`either operating at undesh;ably low pressures or requir(cid:173)
`It is · further an objective
`ing the use of a workover rig.
`of the invention to eliminate the necessity for making
`round-trips with the tubing and also for obviating the
`necessity of killing a well.
`It should be pointed out
`that, while the invention is extremely attractive . in its
`quality of eiiminating the use of a workover rig, the in(cid:173)
`vention also ·offers ·outstanding advantages when used in
`conjunction with woi:kover operations, ·Thus, . the inven(cid:173)
`tion makes it ·possible first to 9omplete a wen that has
`a workdver in progress and . then to subsequently fracture
`the wdl. Otherwise, it would be necessary to again kill
`the ·well after fracturing in order to complete it, thereby
`in ·some cases making it necessary to place undesirable
`high mutl differential pressures ·across a recently fractured
`formation.
`The above-mentioned objectives as well as other ob(cid:173)
`jedives which will ' become ~pparent 'as the ensuing . de~
`'Scfiptfon ·progresses ·are"reiilized 'in 'll'.ccordance · with the
`
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`2,927,643
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`3
`12 in turn is bolted or otherwise secured to the master
`valve 13 which likewise may be of a conventional type.
`Immediately above and bolted or otherwise secured to
`the master valve is a cross 14 which may in turn be
`connected to one or more valves 22 and 23. Such valves
`are conventionally installed at this point in a well head
`assembly for the purpose of withdrawing oil from the
`production tubing within the well, for introducing various
`fluids within the well, etc.
`Immediately above cross member 14 is top valve and a
`lubricator connection 16. These two component parts
`may also be of conventional type and are secured to one
`another and to the well head assembly itself as by means
`of bolted flanges or the like.
`The conventional parts of the well head assembly in
`Fig. 1 having been described, attention is now directed
`to the remaining parts shown there which constitute in
`combination the apparatus of this invention. Thus, one
`such part is the bypass conduit 5 which extends from a
`point vertically below and spaced from the casing head
`10 to a point vertically beyond and spaced above the
`lubricator connection 16. The conduit may be any con(cid:173)
`ventional type of high pressure tubing, piping, or the
`like which is available commercially. The tubing, in ac(cid:173)
`cordance with the invention, is particularly characterized
`by possessing a pressure rating or strength which is
`greater than that of the well head assembly itself. The
`tubing is further characterized by possessing a pressure
`rating or strength which is at least equal to the pressures
`that are required in a fracturing operation.
`At this point it is important to note that, for the pur(cid:173)
`poses of the present description, it is to be assumed that
`the well head assembly in Fig. 1 is mounted on a well
`which is to be fractured at a fracturing pressure far in
`excess of the pressures to which the well head assembly
`may be subjected. Thus, it may be assumed that the
`well head assembly has a pressure rating of the order
`of about 2000 p.s.i.g., and that the desired fracturing
`pressure is of the order of about 6000 p.s.i.g.
`In this
`situation the bypass conduit 5 must be sealed such that it
`has a pressure rating itself at least equal to that of the
`fracturing operation, i.e. of the order of about 6000
`p.s.i.g.
`Prior to the installation of the bypass conduit within
`the production tubing 17, the conduit must be provided
`at its lower end with a packer assembly 8 which is char(cid:173)
`acterized dimensionally by its ability to fit snugly within
`the production tubing 17 and structurally so as to with(cid:173)
`stand the aforesaid fracturing pressure. A variety of
`packer assemblies may be employed for this purpose. A
`packer that has proven to be very effective in a number
`of instances is the type illustrated in Fig. 2. A more de(cid:173)
`tailed description of this packer assembly will be pre(cid:173)
`sented a little later in this description.
`Prior to the installation of bypass conduit 5 within
`the production tubing 17, it is necessary to provide the
`upper member of the well head assembly (i.e. lubricator
`connection 16) with an apparatus adapted to provide a
`seal around the outer peripheral surface of the conduit
`5. An effective apparatus proven in the field for this
`purpose is the combination stuffing box and blow(cid:173)
`out preventer 4 which is illustrated in Figure 1. The
`packing members 36 within the stuffing box body 37
`are compressed against the outer wall surface of the
`conduit 5 by means by the member 32 which is driven
`inwardly of the body member 37 as by means of threaded
`members 33. The blow-out preventer portion of the com(cid:173)
`bination unit 4 consists of closure members 34 which are
`driven inwardly against the conduit 5 as by means of
`threaded members 35.
`At this point it should be noted that the combination
`blow-out preventer and stuffing box 4 may be selected
`from conventional commercial pieces of apparatus and
`that the structure of this member in itself is not a novel
`feature of the invention.· Rather, it is. the combination
`
`4
`of this unit afong with· the other previously mentioned
`and subsequently mentioned parts which constitutes the
`apparatus of the invention.
`The combination blow-out preventer and stuffing box
`5 4 is secured, as by means of the illustrated threaded con(cid:173)
`nections, to lubricator nipple 16 prior to insertion of the
`bypass conduit 5 within any portion of the well head
`below the top valve 15.
`Referring again to bypass conduit 5, it will be seen
`10 that the upper end of this conduit is threaded or other(cid:173)
`wise secured and sealed within a holddown plate 3. This
`plate is suitably pierced and threaded or otherwise ar(cid:173)
`ranged to receive the upper end of conduit 5 and to
`transmit fluids from the conduit to a point beyond the
`i;; plate itself. Thus, the plate may be conveniently pro(cid:173)
`vided with a suitable high-pressure valve 2 and any other
`connection such as a union 1 for conveying fluids in or
`out of the bypass conduit.
`As mentioned earlier, the holddown assembly 3 is held
`20 in place by means of cable members 6 which are fastened
`securely to some suitable fixed point. A fixed point such
`as the well head itself may be used for this purpose.
`The cables holding down the holddown flange may
`conveniently be steel cables, wire cables, steel chain, or
`25 the like. It will be appreciated of course that these hold(cid:173)
`down members may also be in part solid or tubular-like
`It is essential,
`members or even threaded members.
`however, that the cable (i.e. holddown) members be
`provided with means for changing the overall length of
`30 the cable. This may be done, as illustrated, by utiliza(cid:173)
`tion of chain hoists. Other devices such as turn buckles,
`hydraulic cylinders and rams, pneumatic cylinders, and
`the like, may also be adopted for this work. Essentially
`then, the holddown flange, the holddown members and
`35 the apparatus for adjusting the effective length of the
`holddown members combine to act as a snubbing unit for
`moving the bypass conduit 5 relative to the welJhead ap(cid:173)
`paratus proper.
`The various parts that are illustrated in Fig. 1 having
`40 been enumerated and described, attention is now di(cid:173)
`rected toward a consideration of the manner in which
`this apparatus is operated in a well-fracturing opera(cid:173)
`tion. In this vein, it will be considered that the well head
`apparatus illustrated in Fig. 1 is mounted at the top of an
`oil well which it is desired to submit to a fracturing op-
`45 eration.
`It will further be considered that the pro-
`duction tubing within the well is sealed at the bottom
`of the well to the casing by a packer and is of a strength
`sufficient to withstand the pressure of the hydraulic frac-
`50 turing operation, but that the well head apparatus atop
`the well possesses too low a pressure rating for this pur(cid:173)
`pose.
`At the outset of the operation, a flushing oil in the
`form of crude oil or a refined petroleum derivative is
`55 first pumped at low pressures (substantially equal to the
`well pressure) into the production tubing as by means of
`valve 23 and suitable pumps, supply lines, transfer tanks,
`etc. not shown in the figure. After sufficient flushing oil
`has been pumped into the tubing to quiet the well, the
`GO master valve 13 and valves 22 and 23 in the well head
`It will be appreciated that
`assembly may be closed.
`other procedures may be employed for this stage of the
`operation for example, the master valve 13 and valves
`22 and 23 ma1 be closed without any pumping-in oper-
`{j[) ation whatsoever.
`Following the initial step described above, the blow(cid:173)
`out preventer is mounted and secured to the top of the
`lubricator nipple 16, and the bypass conduit 5 with its
`attached packer assembly 8 and holddown assembly 3
`70 is inserted into the top of the well head assembly and
`down into the assembly to a point immediately above
`the closed master valve 13.
`The lifting and insertion of the bypass conduit may
`be achieved as by means of a gin pole or a boom truck
`75 or an:y other coµvenient liftins device. Alternatively~
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`fu(: assembiy may be stripped broken-down into the well
`creasing force in response to increasing pre8sures Within
`the tubing.
`.
`.
`.
`head and tightened up iI1 place.
`.
`Thus, the packer assembly generally consists of a suit-'
`Withthe bypass cimduit in the aforedescribed position
`above the master .valve 13, the conduit valve 2 is closed;
`able mandrel threaded on each end and provided with
`the stuffing box 4 is tightened, the holddown assembly 5 a rubber packer which is adapted to be . thrust radfally
`3 is secured to the bottom of the well head by means of
`outward from the. mandrel when pressure is applied to
`cable 6 and chain hoist 7 or other appropriate holddown
`the collar.
`·
`equipment such as hydraulic cylinders, etc. The master
`The present invention having been described in detail,
`valve is now opened and the bypass conduit is lowered
`it will be noted · that numerous variations and modifica_.
`If there is no pressure 10 tions may be employed without departing from the spirit ·
`into the production tubing 17.
`or substantially no pressure within the well, the bypass
`or scope of the invention. · Thus, . the apparatus may:
`conduit may be lowered of its own weight into the tubing.
`be constructed of steel or any of the other metals or'·
`If the well is under pressure, however, the chain hoist
`metal alloys that are conventionally employed in ap-
`7 or other appropriate equipment may be employed to
`paratus of this type. Furthermore, a variety. of tubing
`·pull . the assembly downward. . Any pressure within the 15 hangers, ' valves, blow-out preventers, tubing clamps,· etc.
`well reacts against the cross sectfonal area of the conduit
`may be used to suit any particular type of well or well
`untilthie packer assembly 8 enters within the production
`head construction. Furthermore, devices other ,than the.
`tubing. At this point the pressi.ire reacts opposite the
`chain and chain hoist apparatus may be • e!Dployed to
`cross sectional area of the inside of the tubing. As the
`regulate the movement of the bypass conduit within the
`bfoass conduit is forced downward within the tubing 17, 20 well head assembly. Hydraulic cylinders, · pneumatic
`the packer assembly 8 slides along the inner surface of
`cylinders, etc. may be readily adapted for. this purpose,
`the tubing but continues to maintain its sealing position
`and hydraulic cylinder or ram means. are preferred.
`with respect to the tubing.
`The great value of the invention is perhaps best illus-
`bnce the · bypass conduit has been lowered to a pre-
`trated by reference to the following · example in which
`determined suitable position and tightly fastened, a pump 25 the invention was employed in an actual fracturing oper- .
`frt1ck oi: other ptimping apparatus may be connected to ·
`ation.
`In this operation a well, which was . provided
`the top end connection of the bypass conduit · 5, and a..
`with 51;2" casing and 21h" production tubing with · a·
`frai:turing liquid may be forced down . within the con-
`7260 p;s.i.g. internal bursting pressure, was desired to. be
`duit and the production tubing to the formation that fa
`fractured at a pressure of the order of 6000 p.s.i.g. The
`to be fractured. Since the packer assembly seals the -30 well head was constructed of series 600 valves and other
`well head components from the fracturi11g pressure, there
`fittings and therefore was characterized by a working
`is no danger of the pressure rtipturing or damaging the
`· pressure · rating of 2000 p.s.i.g. and a .test pressure• rating
`of 4000 p.s.i.g. As is conventional In the art, the lower
`well head.
`.
`.
`end of the production tubing was· sealed to t _he casing
`Following the fracture treatment, the pumping ap-
`paratus may be disconnected, the holddown released and 35 adjacent the producing formation by means of packers','
`To have performed this operation · without the use of
`If the well
`the bypass conduit removed from the well.
`head is under pressure, . the assembly valve 2 should be
`the present invention, it would have . been nece5sary to
`closed arid the holddown assembly 3 or other appropriate
`kill the well, to take off the well head; to perform the
`eql1ipnient released slowly while removing the overall
`fracture · without the tubing head and to · then . reinstall
`assembly to a point just above the master valve. . When 4o the tubing head and bring in the well. This procedure
`the packer assembly · 8 clears the master valve ·· 13; that
`-would have entailed a period· of at least four days . .. With
`valve may be shut and the bypass assembly · remoyed
`the present invention the entire operation tOok only four
`from the · well.
`hours.
`· ·
`· ·
`fo. carrying out the operation in accordance with the
`It has been mentioned earlier irt this description that
`the packer assembly 8 in Fig. 1 may conveniently be 45 present invention, a 11h" double extra strong steel pipe
`of a construction such · as is illustrated in Fig. 2. Tum-
`was used as a ·bypass conduit and was provided at its
`ing then to Fig. 2, it will be seen that this form of packer
`upper end \vith a 1", 15,000 lb. valve and a 2" 15,000 lb,
`union. -A 3,000 lb. test blow"out preventer was mo1mted
`assembly
`includes an elongated, . cylindrically-shaped
`mandrel 50 which possesses a central passageway 51 ex-
`a~ the top ofthe well head -along with suitable clamping
`. tending the entire length of the mandrel.
`50 apparatus for holding the bypass conduit in a fixed posi-
`ti on. The blow-out preventer was required since the . w~Il
`The mandrel 50 is provided with a threaded section 52
`at one end which is ad'1pted to be connected with the
`had a natural well head pressure ·of. the order of 800
`lower end of the bypass conduit. The mandrel · is further
`p.s.i.g.
`The bypass . conduit was lowered into thewell head to a
`provided . with a threaded lower end 60 which may be
`connected to a suitable end piece 59 or a second such 55 point immediately above the closed master valve and was
`It may be desirable on occasion, especially in .
`held in position by means of four 6-ton chain hoists and
`mandrel.
`very high pressure. wells, . to employ two or more snch
`% " wire rope. At this point the blow-out preventer was
`packers in series. Hence, the provision is made for con-
`forced against the bypass conduit; the master valve. was
`necting more than one of these packers together in one
`O!Jened, and the chain hoists were operated to force· the
`60 conduit dowri within the production tubing. The con-
`integrated assembly.
`At a point intermediate the end of the mandrel 50, a _
`duit was provided at its lower end with a double packer
`rubber packer or other elastic collar· 61 is mounted · upon
`of the type shown . in Fig. 2. Once the . packer was in
`the mandrel and secured there as by ineans ()f locking
`position within the production tubing, fracturing fluid was
`It will be. appreciated
`Tecess 54 and retaining pins 53.
`pumped into the bypass conduit and thence into the.pro-
`that the rubber packer 61 may be bonded directly to the
`duction tubing and down to the producing formatfon at. a
`mandrel 50. Thie rubber packer 61 is held in position on
`pres,sure up to 6800 p.s.i.g. Maximum differential preS-
`the mandrel as by means of a locking gland 56 which is
`sures: of the order of 5000 p.s:i.g . . were observed across
`pressed against the rubber packer 61 by means of a com-
`the two packers, 1800 p.s.i.g. being maintained on the
`pressed spring 57. The spring in turn is anchored suit- 70 well head. The• maximum pressure on the well head
`itself never exceeded a safe value of 1800 p.s.i.g.
`ably by a shoulder member 58 . which is secured to or
`held in position by the end piece 59.
`Following the fracturing operation,
`the bypass .con-
`The rubber packer 61 is preferably flared as indicated
`duit and associated equipment were removed from the
`so as to contact the inner . wall surface of a production
`well head assembly and the well returned to a producing
`tubing and to be thrust against the tubing with ever in- 75 condition.
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`65 .
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`2,927,643
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`7
`What is claimed is:
`1. An apparatus for bypassing the well head assembly
`of a well apparatus and for isolating the assembly from
`the pressure prevailing within the well wherein the well
`apparatus is provided with a production tubing and a well
`head assembly including a master valve which apparatus
`comprises in combination an elongated conduit having
`an overall diameter which is smaller than the diameter of
`the passageway extending through the master valve and
`into. the production tubing, a packer assembly movable
`through said passageway and mounted on the lower end
`portions of said conduit for forming a seal in the annular
`space between the production tubing and said conduit,
`sealing means disposed around the upper end of said con(cid:173)
`duit for effecting a seal between the wall of said passage(cid:173)
`way and said conduit, means including a vaive in said con(cid:173)
`duit for introducing and withdrawing fluid to and from
`the interior of said conduit, and snubbing means for mov-
`ing the conduit in vertical relation to the production
`tubing.
`2. An apparatus for the transfer of fluid within a well
`apparatus wherein the fluid is at a pressure greater than
`the operating pressure of the well apparatus head assem(cid:173)
`bly atop the well but not greater than the operating pres(cid:173)
`sure of the production tubing within the well which ap(cid:173)
`paratus comprises in combination an elongated vertically
`disposed conduit having a smaller outside diameter than
`the passageway defined by the master valve and the pro(cid:173)
`duction tubing, a packer assembly movable through said
`passageway mounted at the lower end portions of said
`conduit for blocking off the annular space between the
`conduit and the production tubing, means for snubbing
`the conduit through the master valve and into the produc(cid:173)
`tion tubing, and means including a valve in said conduit
`for transferring fluid within said conduit.
`· 3. An apparatus for introducing a treating fluid with(cid:173)
`in a well apparatus wherein the fluid is at a pressure
`greater than the safe operating pressure the well head as(cid:173)
`sembly including the master valve will withstand but not
`greater than the safe operating pressure of which the pro- 40
`duction tubing within the well is capable which apparatus
`comprises in combination an elongated vertically disposed
`conduit having a safe operating pressure greater than the
`pressure of the fluid introduced, a packer assembly mount-
`ed at the lower end portion of said conduit, said con- 45
`duit and said packer assembly being freely movable
`
`35
`
`5
`
`8
`through the passageway defined by said master valve
`and said production tubing, snubbing means for mov(cid:173)
`ing said conduit and said packer assembly through said
`passageway, means including a valve in said conduit
`for establishing the flow of said treating fluid within said
`conduit, and means for effecting a seal between said con(cid:173)
`duit and the inner wall of said passageway near the upper
`end of said conduit.
`4. An apparatus for bypassing the well head assembly
`10 of a well which contains a production tubing and for iso(cid:173)
`lating the well head from the pressure prevailing with(cid:173)
`in the well wherein the well head assembly includes a
`master valve and a lubricator connection which com(cid:173)
`prises in combination an elongated conduit of smaller
`15 outside diameter than the port in the master valve ·and
`the inner diameter of the production tubing, a packer on
`the lower end of said conduit adapted to move through
`said port and said tubing and actuated to block off the an(cid:173)
`nular space between the conduit and the production tub-
`20 ing, a holddown flange sealed to the upper end of said
`conduit, at least one holddown member of adjustable
`length securing said holddown flange to a fixed support,
`means including a valve for establishing fluid flow within
`said conduit, and sealing means disposed around an upper
`25 portion of said conduit for sealing the space surrounding
`said conduit within said well head assembly from the
`atmosphere.
`5 .. An apparatus as defined in claim 4 in which the
`sealing means is a combination blow-out preventer and
`30 stuffing box.
`
`1,895,132
`2,087,528
`2,143,251
`2,162,179
`2,174,001
`2,211,206
`2,259,429
`2,335,355
`2,673,615
`2,766,828
`
`References Cited in the file of this patent
`UNITED STATES PATENTS
`Minor ----------------- Jan. 24, 1933
`Otis ------------------- July 20, 1937
`Savitz ------------------ Jan. 10, 1939
`Mueller ----------------June 13, 1939
`Howard ----------------Sept. 26, 1939
`Howard---------------- Aug. 13, 1940
`Simmons---------------- Oct. 14, 1941
`Penick et al. -~--------- Nov. 30, 1943
`Humason ------------- Mar. 30, 1954
`Rachford -------------- Oct. 16, 1956
`FOREIGN PATENTS
`Netherlands ------------ May 15, 1952
`
`70,001
`
`000005
`
`