US2159541A - Blowout preventer - Google Patents

Description

Patented May 23, 1939 UNITED STATES PATENT OFFICE} nLoWoU'r rnnvnu'rna" John w. MacClatchie, Newliall, cum, assignor to MacClatchie Manufacturing Company oi California, Compton, Call! a corporation of California Application May 19, 1937. Serial No. 143.411 4 Claims. (01. 166-15) 1o In the invention described in'my above mentioned application, the packing of the cooperating closure elements is adapted dor pressmeresponsiye"expansible distortion after the closure elements have been relatively radially contracted 1 around a well stem whereby the packing seals tightly around the well stem even though the-latteris non-circular in cross-section, e. g.'a square telly."

An obiect of my invention is to provide a strucgo ture which is adapted to receive a drill stem'which is non-circular in cross section, which permits the usual operation oi the drill stem, which is adapted to seal of! against the drill stem, and

- against which structure cooperating closure ele- 5 ments are adapted to be relatively radially contractible. The advantage oi such a structure is that the cooperating closure elements are enabled to'eile'ct a tight seal without subjecting the packing material of the closure elements to the amount 3o '01 expansible distortion required without the use of such a structure to seal oil against a. noncircular drill stem as described in my above mentioned copending application.

It is a iurtherobiect my invention to pro-- 5 vide a structure which is adapted to be mounted in the opening 0! the housing which is adapted to receive the drill stem and which' consists of a "non-rotatable'member and a rotatable member mounted in said now-rotatable member, and in v 0 which the rotatable member has anon-circular bore, formed in'part ot pacldng material, which isadapted to receive. the non-circular drill stem and ,which is adapted to'permit the usual opera- 7 tion ,0: the-drill stem, such as vertical and roas tational movement therethrough.

= Still another object of my'invention is to provide a meansoi. sealing of! between the'rotatable member andthe drill stem;

' till another object 0! my invention is to mount 50 the rotatable member on anti-frictional bearings in the non-rotatable. member and to also provide a means of sealing'oii between the nonrotatable member and the rotatable member.

Other and i'urther objects and advantages 0! a ing specification and by reference to the accompanying drawing, in which an example of the invention is shown, and wherein;

Figure 1 is an elevational sectional view of th blowoutpreventer, showing the blowout preventer 5 in operative position.

Figure 2 is a section taken on the line 2-2 oi. Figure 1.

Figure 3 is a section taken on the line 8-3 of Figure 2. a 10 The blowout preventer'is incorporated in a string of well casing i which is adapted to receive a well stem shown in the present instance as a usual kelly 2; and the blowout preventer comprises cooperating closure elements I which are -1 adapted for relative radial contraction around a structure for the well stem as shown in Figures 1 and 2, or relative radial expansion to clear the bore of the well casing. The closure elements project radially from a housing 5 which is con- :0 nected to proximate lengths oithe string of wellcasing l and which has a bore 6 iorming'a proiongation of the bore I of the well casing. The structure against which the closure elements I non-circular drill stem is adapted to extend is mounted in the bore 6 oi' the housing 5. The

housing I is provide'd with an internal flange 8 which extends into the bore 0. Rigidly but removably secured to said flange I is a bearing so flange ill.

As shown in Figure 3, attached to the bearing flange ll by means oi screws Ii is an annular non-rotatable member i2, the lower portion of which is provided with ashoulder ll. Arotatable as retaining means which is adapted to be rotated with a non-circular drill stem is adapted to be anti-irictionally mounted in the non-rotatable member l2.

As an instance of this arrangement the rotat- 40 able retaining means may consist oi an annular bearing retaining member it, having a recess II, and a shoulder ll, packing gland nutll, packing gland washers II and i9, and packing".

The packing gland washer I! may be provided g with a shoulder 2| which is adapted to:- engagement with the shoulder ii of the bearing retaining member I4 and thereby prevents any downward movement of the packing washer l9.

In order to provide for both end and lateral thrust and thereby insure operation with a minimum oi frictional resistance, ball bearings 25 are provided between the shoulder in and the bearing retaining member ll, ball bearings It between the bearing retainingmember ll and g5 the shoulder ii of non-rotatable member i2, and

roller bearings 21 are provided in the recess l5 between the non-rotatable member 12 and the bearing retaining member 14.

The packing which is provided between the lower end of the non-rotatable member i2 and the packing gland washer [9 for preventing escape of well pressure is so arranged as not to obstruct free rotational movement of the rotatable retaining means with relation to the nonrotatable members and for this purpose the lower part of the non-rotatable member l2 may be recessed as indicated at 2 8 for the reception of a ring of inverted U packing 29. The inverted U packing 29 is mounted in the recess 28 with the interior of the ring open to well pressure from the bore 1 of the casing by means of an opening 30 in the lower end of the member i2, so that the packing may be operatively expanded for packing off between the lower end of the member i2 and the packing gland washer IS.

The packing 29 is also designed to prevent drainage from the space surrounding the bearings 25, 26, and 21 so as to seal against the escape of a lubricant which may be supplied to said space for lubricating the bearings, and a packing ring 3| is preferably secured to the bearing flange i0 and packs off against the packing gland nut II for similarly seating the opposite end of the space for the lubricants.

The packing gland nut -li and the packing gland washers l8 and I9 may be of any suitable wear resisting material such as a suitable metal. The packing may be of any resilient material such as rubber and is designed to permit the usual operation of the kelly. For convenience', the packing may be in the form of a plurality of washers with non-circular bores. The packing gland washers l8 and i8 and the packing-2ll are provided with non-circular bores which are only slightly larger than the dimensions of the non-circular drill stem, and are preferably split so that they may be readily mounted on said drill stem.

45 The packing gland'nut I1 is threaded into the bearing retaining member II as indicated at 32 and is adapted to be tightened by a suitable wrench against the'packlng gland nut it, therecontained therein.

by squeezing and expanding the packing 2i! and eflecting a tight seal between the bearing retaining member I4 and the non-circular drill stem 2.

When it is desired to add another length of drill pipe to the drill string, the screws securing the bearing flange III to the internal flange 8 are removed. The kelly may be then raised carrying with it the bearing flange Ill, the non-rotatable member I2 and the rotatableretaining means After the additional drill pipe has beenadded to the drill string the kelly carrying with it the bearing flange iii, the nonrotatable member l2 and the rotatable retaining means is again lowered into the housing 5 and reassembled as described hereinabove.

The closure elements 3 may be reciprocated in cylinders l toprovide for their relative radial expansion or contraction, the cylinders project ing radially from the housing 5. The cylinders 4 open into the bore 6 and are equi-distantly circumferentially spaced around the housing 5. In the present instance the cooperating closure elements are three in number, and therefore the housing! is. formed with three of the radially proiectingcylinders 4, though any convenient plurality of closure elements may be used.

The closure element in each cylinder l comprises a packing cup 40 and one or more cooperating abutment plates II. The abutment plates prevent distortion of the packing cups longitudinally of the bore 6 when the closure elements are relatively radially contracted around the nonrotatable member i2, and since this distortion may be in either of opposite directions, an abutment plate ll is preferably provided both above and below the cup 40 as shown at Fig. 1. When the closure elements are relatively radially contracted around the non-rotatable member l2, the abutment plates ll above the packing cups cooperate to define a closure means in the annular space between the non-rotatable member l2 and the wall of the bore 6 for preventing upward distortion of the packing cups, and the abutment plates 4| below the packing cups similarly cooperate to define a closure means in said annular space for preventing downward distortion. of the packing cups of the well casing.

Each packing cup 40 is adapted for pressure responsive shifting along its cylinder 4 until relative radial contraction of the closure elements around the non-rotatable member i2 effects a closure means in the annular space between the non-rotatable member l2 and the wall of the bore 6, and shifting of the closure elements being then arrested, the fluid pressure expands and distorts the bottoms 40a of the packing cups member l2. For this purpose each packing cup is of yieldable material and is preferably resilient, e. g. rubber or the like, and is preferably a deep cup, the wall 40b of which fits snugly in the bore of cylinder 4 with the wall preferably tapering to a thin lip 40c, and with the bottom Illa of the cup of appreciable thickness and having an outer surface tapered as shown at 4001, with an arcuate recess Me at the apex of the taper and having its axis parallel to the axis of the bore 6.

Fluid pressure'in the cylinders 4 in back of the packing cups seals the walls of the cups against the cylinder walls and then shifts the cups in their cylinders until thetapering surfaces 40d of next adjacent cups abut, the angles of the surfaces 40d being such that these surfaces of the plurality of cups will abut when the packing cups have formed a complete closure around the non-rotatable member 12; and the arcuate recesses we of the plurality of cups are arranged so as to cooperate to define a bore at the axis of the housing 5 when the packing cups have been projected to operative position, with this bore of a size to receive the non-rotatable member l2. When the cup packings have I been thus operatively projected and their movement has been arrestedby abutment of their surfaces 40d, fluid pressure in the cups distorts and expands the bottoms of the cups in order to tightly seal thepacking cups around .the nonrotatable member i2..

The abutment plates H are shown as partially encircling the upper and lower portions of the peripheries of the packing cups, and are adapted for retraction and projection with the cups. For this purpose the upper and lower portions of the peripheries of'the packing cups are arcuately recessed for some appreciable distance from the bottoms of the cups along their axial length, and theplates ii are arcuate plates received in said recesses with the outer peripheries of the plates prolonging the peripheral working surfaces of the pistons which are formed by the cuppackings, The outer ends of'the plates 4| taper as shown at 4|d andare recessed to corre- When'the packing cups are shifted in their cylinders to operative position, the plates 4| are thus also operatively projected; and when the surfaces 48d of the packing cups abut, the surfaces 4|d of the plates 4| similarly abut for arresting further relativeradial contraction of the closure elements while permitting expansible distortion of the bottoms of the 'cup packings to complete the seal as previously described. In practice the arcuate recesses 48a of the packing cup and of the abutment plates are preferably of such depth that when the closure elements are relatively radially contracted around the nonrotatable member l2, the bore which is deflned by said recesses, prior to expansible distortion of the bottoms 48a of thejpa'cking cups, is very slightly 'largerthan the circumference of the non-rotatablemember l2. The expansible dis-' tortion to which the bottoms 48a of the cup'packings 48 are then subjected closes this space so that the packing seais'tightly around the annular member l2 with the small space-which still remains between the-plates 4| and the annular member I2 of such restricted area that, the plates 4| will effectively prevent excessive distortion of the packing vertically in the bore 8.

Means are provided for retracting the closure elements within their cylinders so as to relatively radially expand them from theiroperative position, and said means is preferably fluid operated.

As an instance of'this arrangement a cover plate 44 for the outer end of each ofthe cylin ders 4 may have a depending extension 44a forming a cover-plate for acylinder "which is flxed to the cover plate so, as to extend parallel to the overlying cylinder 4, and a piston 48 is adapted for reciprocation in each of the cylinders 48. At each of-the cooperatingcylinders 4-48, a lever 48a is medially pivoted to a supporting arm 41 which-may project from the cover plate 44-44a, and one end of this lever is connected to a rod which is connectedto the closure element 8, and the opposite end of the lever is connected to a piston rod 48 which is secured to the piston 48. when fluid pressure is sup plied to the cylinder 4 and exhausted from the cylinder 48, the closure element 8 is thus shifted in its cylinder to its operative position. thereby retracting the piston 48 in its cylinder 48 and when fluid pressure is exhausted from the cylinder 4 and is supplied to the cylinder 48, the piston 48 is projected, thereby retracting the closure element 8.

A flexible connection is preferably provided between the rod 48 and the closure element 8, whereby the rod retracts the closure element when the piston 48 is projected; but when the closure element is shifted to operative position responsive to fluid pressure in the cylinder 4, the

packing cup of the closure element may distort relative to the rod 48 so as to permit sealing engagement by the packing cup with the -wall of the cylinder 4 and around the non-rotatable member I2, without strain on the rod 48. As an instance of this arrangement a spider 88 may be fixed to the rod 48, with its periphery comprising a plurality of circumferentially spaced arcuate members II. and the members 8| are slotted for reception of tongues 82 of arcuate members 88 which are adaptedv for reception in arcuate grooves 84, in the inner'peripheral surface of the side wall 48b of the packing cup. This con- 48 against relative longitudinal displacement for retracting the packing cup when the rod is retracted, but permits radial displacement of the side wall 48b of the packing cup with relation to the rod 48, so that when the packing cup is operatively projected responsive to fluid pressure, the pressure may radially distort the cup with relation to the rod 48 in order to insure an effective seal, without transmitting strain to the rod 48.

Means are provided for substantially simultane'ously supplying fluid pressure to the plurality of cylinders 4 and exhausting the plurality of'scylinders 48, or exhausting the plurality ofcylinders 4 and supplying fluid pressure to the plurality of cylinders 48. As an instance of this arrangement a manifold 88 may extend around the housing 8 below the cylinders 4 and radially inwardly from the cylinders 48, and the manifold may be provided with a pair of conduits 8l-82. Below each of the cylinders 4 a pair of conduits 88-84 extend parallel to said cylinder, with the inner ends of said conduits communicating respectively with the conduits 8l-82. The

"outer ends of each of the said conduits 83 opens into its cooperating cylinder 4 as shown at 88 and eachcof the conduits 84 opens into its cooperating cylinder 48 as shown at 88, and when fluid pressure is exhausted from the cylinders 4, the fluid preferably drains through the conduits '88 into the conduit 8|. r I

When fluid pressure is supplied to the conduit 8| and the conduit 82 is open to the atmosphere, the closure elements 8 are thus shifted to operative position; and when fluid pressure is supplied to the conduit 82 and the conduit 8| is open to the atmosphere, the pistons 48 retract the closure elements 8 to their inoperative position. Pipes 81-88 may be connected to the conduits 8i-82 for supplying and exhausting fluid pressure, anda valvular" control 89, which may .be

ranged so that movement thereof in one direction supplies fluid pressure to the conduit 8| and exhausts the conduit 82, while movement of the valvular control in the opposite direction exhausts the conduit 8| and supplies fluid pressure to the conduit 82.

For this purpose the valvular control is shown as a plug valve, the casing of which has an inlet port 18 connected to a source of fluid pressure, a port 1| which may open to the atmosphere, and a pair of ports 12-18 connected to the pipe 81-88 respectively.

The plug of the valve has passageways 14-18 arranged so that when the plug is turned to the position shown at Fig. 2' the pipe 88 exhausts to the atmosphere and the pipe 81 is open to the fluid pressure supply, and when turned ninety degrees the pipe 88 is open to thefluid pressure supply and the pipe 81 exhausts to the atmosphere.

In operation the annular space betweenthe nection secures the packing cup 48 and the rod i "elements arrested by abutment of the surfaces lid-d of the cooperating closure elements. Continued fluid pressure exerted against the cup packings then expansively radially distorts the bottoms a 'of the cups so that they seal around the non-rotatable member II, with the abutment plates ll prevent ng distortion of the packing cups vertically of the bore 6. Suflicient pressure may be maintained in the cylinders l as will hold the seal against any well pressure liable to be encountered.

In wells in which only low pressures are .encountered or by the use of suitable packing material, the abutment plates ll may be omitted.

Although I have described my invention in connection with the use of three cooperating closure elements, excellent results can be obtained by the use of two, or any other convenient plurality of closure elements.

Although I have described my invention with respect to certain particular embodiments thereof, nevertheless I do not desire to be limited to the particular details shown and described except as clearly specified in the appended claims, sincemany changes, modifications and substitutions may be made without departing from my invention in its broader aspects, which may be found useful in many other applications thereof.

I claim:

1. Closure means for a well casing, including a stationary body arranged to be mounted on a well casing, a non-rotatable member arranged for direct'vertical movement into and out of said body, a rotatable member in said non-rotatable member and movable vertically therewith, a closure means in said body relatively radially contractible for sealing around said non-rotatable member, the portion of said closure means which is adapted to seal around said non-rotatable member being formed of packing material, and means functioning independently of pressure in the bore for exerting fluid pressure against said portion of said closure means for expansibly distorting said packing material for projection against and into sealing engagement with said non-rotatable member.

2. In a blowout preventer, ahousing having a bore arranged to be mounted on a well casing, a plurality of cylinders opening into said bore, a non-rotatable member arrangedfor direct vertical movement into and out of said boreya rotatable member in said non-rotatable member and adapted to be moved vertically therewith,

closure elements in each of said cylinders radially v movable into sealing engagement with said nonrotatable member, the portions of the closure elements which are adapted to abut said nonrotatable member being formed of packing material and adapted for expansive distortion into said bore, and means for expansively distorting the packing material for projection into the bore for sealing around said non-rotatable member. 3. Closure means for a well casing, including a stationary body arranged to be mounted on a member and said rotatable member arranged to be expanded by fluid pressure, and closure elements mounted in said stationary body and adapted to be expanded by fluid pressure other than well casing pressure for sealing around said cylindrical non-rotatable member.

4. Closure means for a well casing, including. a stationary body arranged to be mounted on a well "casing, a cylindrical non-rotatable member arrangedfor direct vertical movement into and out of said body, a rotatable member adapted to be mounted entirely within said cylindrical nonrotatable member, anti-frictional end and lateral bearing means between the rotatable member andthe non-rotatable member, sealing means between the cylindrical non-rotatable member and the rotatable member adapted to be expanded by well pressure, a packing in said rotat able member'for engaging and packing ofl a drill pipe, whereby said members may be bodily raised and lowered into said body by said drill pipe, and closure elements mounted in said stationary sure other than well casing pressure for sealing around said cylindrical non-rotatable member.

JOHN w. mccm'rcnm body and adapted to be expanded by fluid pres-' 5

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